As filed with the Securities and Exchange Commission on September 3, 2013.March 1, 2022

Registration No. 333-               

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON,Washington, D.C. 20549

FORMForm S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

KaloBios Pharmaceuticals,Humanigen, Inc.

(Exact name of registrant as specified in its charter)

260 East Grand Avenue

South San Francisco, CA 94080830 Morris Turnpike, 4^th Floor

(650) 243–3100Short Hills, New Jersey 07078

(973) 200-3010

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

David Pritchard

Cameron Durrant, M.D.
Chief Executive Officer
Humanigen, Inc.
830 Morris Turnpike, 4^th Floor

KaloBios Pharmaceuticals, Inc.Short Hills, New Jersey 07078

260 East Grand Avenue(973) 200-3010

South San Francisco, CA 94080

(650) 243–3100

(Name, address, including zip code, and telephone number, including area code, of agent for service)

CopiesCopy to:

Bennett

Kevin L. Yee, Esq.

Richard C. Blake, Esq. Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP 1200 Seaport Boulevard Redwood City, CA 94063 (650) 321-2400Vold
Polsinelli PC
1401 Eye Street, NW, Suite 800
Washington, DC 20005
(202) 783-3300

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box:box.  ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box:box.  xþ

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:offering.  ¨o

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:offering.  ¨o

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box:box.  ¨o

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box:box.  ¨o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer”filer,” “smaller reporting company” and “smaller reporting“emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

CALCULATION OF REGISTRATION FEEIf an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ¨

The Registrantregistrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrantregistrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until thisthe Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This registration statementRegistration Statement contains two prospectuses:

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The sales agreement prospectus immediately follows the base prospectus. The $50,000,000 of common stock that may be offered, issued and sold by the registrant under the sales agreement prospectus is included in the $100,000,000$200,000,000 of securities that may be offered, issued and sold by usthe registrant under the base prospectus. Any portion of the $75,000,000 included in the sales agreement prospectus that is not previously sold or included in an active placement notice pursuant to the sales agreement is available for sale in other offerings pursuant to the base prospectus, and if no shares are sold under the sales agreement, the full $75,000,000 of securities may be sold in other offerings pursuant to the base prospectus and a corresponding prospectus supplement.

The information in this prospectus is not complete and may be changed. We may not sell thethese securities pursuant to this prospectus until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy or sell these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED SEPTEMBER 3, 2013MARCH 1, 2022

PROSPECTUS

$100,000,000

KALOBIOS PHARMACEUTICALS, INC.

BY THIS PROSPECTUS, KALOBIOS MAY OFFER, FROM TIME TO TIME:

COMMON STOCK

WARRANTS

UNITS 

KaloBiosCommon Stock
Preferred Stock
Warrants

Rights
Units

_________________________

We may offer and sell, from time to time, in one or more seriesofferings, together or issuances and on terms that KaloBios will determine at the time of the offering,separately, our common stock, preferred stock, warrants, rights or any combination of the foregoing, either individually or as units composed of one or more of the other securities. We may also offer securities described inas may be issuable upon conversion or exchange of any securities registered hereunder. This prospectus provides you with a general description of the securities. The aggregate public offering price of all securities issued by us under this prospectus up to an aggregate amount of $100,000,000.may not exceed $200,000,000.

We

Each time we offer and sell securities, we will provide specific terms of any offering in a supplement to this prospectus. Any prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus.prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement as well asbefore you invest in any of our securities.

We may offer and sell the documents incorporated or deemed to be incorporated by referencesecurities described in this prospectus before you purchaseand any of the securities offered hereby.

These securities may be offered and sold in the same offering or in separate offerings;prospectus supplement to or through one or more underwriters, dealers and agents;agents, or directly to purchasers. The namespurchasers, or through a combination of these methods. If any underwriters, dealers or agents are involved in the sale of ourany of the securities, their compensationnames and any over-allotment options held byapplicable purchase price, fee, commission or discount arrangement between or among them will be describedset forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus titled “About this Prospectus” and “Plan of Distribution.”Distribution” for more information.

No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

Our common stock is listed on The NASDAQ Globalthe Nasdaq Capital Market under the symbol “KBIO.“HGEN.” We will provide information in any applicable prospectus supplement regarding any listing of securities other than sharesOn February 28, 2022, the last reported sale price of our common stock on any securities exchange.the Nasdaq Capital Market was $2.03 per share.

INVESTING IN OUR SECURITIES INVOLVES SIGNIFICANT RISKS. SEE “RISK FACTORS” BEGINNING ON PAGE 4 OF THIS PROSPECTUS AND IN THE APPLICABLE PROSPECTUS SUPPLEMENT BEFORE INVESTING IN ANY SECURITIES.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The dateInvesting in our securities involves significant risks. See “Risk Factors” on page 5 of this prospectus, in our most recent Annual Report on Form 10-K, in our Quarterly Reports on Form 10-Q and in any applicable prospectus supplement. You should read this prospectus, any accompanying prospectus supplement and the documents incorporated by reference herein and therein carefully before you make your investment decision.

_________________________

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

_________________________

This prospectus is dated           , 20132022.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the U.S. Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf process,registration statement, we may from time to time,offer or sell any combination of the securities described in this prospectus, from time to time, and in one or more offerings, up to a total dollar amount of $100,000,000.

This prospectus provides you with a general description of the securities we may offer.$200,000,000 as described in this prospectus. Each time that we offer and sell securities, we will provide a prospectus supplement to this prospectus that will containcontains specific information about the securities being offered and sold and the specific terms of that offering. The prospectus supplement may also add, to, update or change information contained in thethis prospectus and, accordingly,with respect to that offering. If there is any inconsistency between the extent inconsistent, information in this prospectus is superseded byand the applicable prospectus supplement, you must rely on the information in the prospectus supplement.

The prospectus supplement to be attached to the front of this prospectus may describe, as applicable: the terms of the. Before purchasing any securities, offered; the public offering price; the price paid for the securities; net proceeds; and the other specific terms related to the offering of the securities.

Youyou should only rely on the information contained or incorporated by reference incarefully read both this prospectus and anythe applicable prospectus supplement, or issuer free writing prospectus relatingtogether with the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.”

We have not authorized anyone to a particular offering. No person has been authorized to giveprovide you with any information or to make any representations in connection with this offering other than those contained or incorporated by reference in this prospectus or any accompanyingapplicable prospectus supplement prepared by, or on behalf of, us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any related issuer free writing prospectus in connection with the offering described herein and therein, and, if given or made, suchother information or representations mustthat others may give you. We will not be relied upon as having been authorized by us. Neither this prospectus nor any prospectus supplement nor any related issuer free writing prospectus shall constitutemake an offer to sell or a solicitation of an offer to buy offeredthese securities in any jurisdiction in which itwhere the offer or sale is unlawful for such person to make such an offering or solicitation. This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits.

You should read the entire prospectus and any prospectus supplement and any related issuer free writing prospectus, as well as the documents incorporated by reference into this prospectus or any prospectus supplement or any related issuer free writing prospectus, before making an investment decision. Neither the delivery of this prospectus or any prospectus supplement or any issuer free writing prospectus nor any sale made hereunder shall under any circumstances imply that the information contained or incorporated by reference herein or in any prospectus supplement or issuer free writing prospectus is correct as of any date subsequent to the date hereof or of such prospectus supplement or issuer free writing prospectus, as applicable.permitted. You should assume that the information appearing in this prospectus anyand the applicable prospectus supplement orto this prospectus is accurate as of the date on the respective covers of such documents, and that any documentinformation incorporated by reference is accurate only as of the date of the applicable documents,document incorporated by reference, regardless of the time of delivery of this prospectus, such prospectus supplement or any sale or issuance of securities.a security, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed materiallysince that date.

Humanigen, Inc.

Attention: Corporate Secretary
830 Morris Turnpike, 4^th Floor

Short Hills, New Jersey 07078

(973) 200-3010

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Our third antibody, KB004 (a Humaneered®, recombinant anti-EphA3 receptor tyrosine kinase monoclonal antibody), is in the dose escalation portionTable of a Phase 1 clinical trial in patients with hematologic malignancies. We plan to initiate the Phase 2 expansion phaseContents

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement and the documents incorporated by reference herein and therein may contain forward-looking statements that are based on management’s beliefs and assumptions and on information currently available to management. They can be identified by the use of forward-looking words, such as “anticipate,” “believe,” “could,” “estimate,” “expects,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” or the negative of these terms or other comparable expressions that convey uncertainty of future events or outcomes, although not all forward-looking statements contain these terms. Forward-looking statements may include, but are not limited to, statements about our expectations regarding: our beliefs as to the potential benefits of lenzilumab as a treatment for hospitalized COVID-19 patients; the timeline for announcement of release of topline results from the ACTIV-5/BET-B study being conducted by the National Institutes of Health; our efforts and potential timeline to make future regulatory submissions in respect of potential emergency use authorization or other marketing authorization or approval from applicable regulatory agencies in the United States, United Kingdom, European Union and other foreign jurisdictions for commercial use of lenzilumab in COVID-19 patients; our other plans to initiate or participate in planned clinical trials and otherwise explore the effectiveness of lenzilumab and our other product candidates in our development portfolio as therapies for other inflammation and immune-oncology indications; our opportunity to benefit from various regulatory incentives; expectations for our financial results, revenue, operating expenses and other financial measures in future periods; the availability and adequacy of our sources of liquidity to satisfy our working capital needs, capital expenditures, and other liquidity requirements and continue as a going concern; and any statement that contains forward-looking words and other similar expressions.

The forward-looking statements included in this prospectus, any prospectus supplement and the documents incorporated by reference herein and therein reflect our current expectations and beliefs, and we do not undertake publicly to update or revise these statements, even if experience or future changes make it clear that any projected results expressed in this prospectus, any prospectus supplement and the documents incorporated by reference herein and therein will not be realized. In addition, the inclusion of any statement in this prospectus, any prospectus supplement and the documents incorporated by reference herein and therein does not constitute an admission by us that the events or circumstances described in such statement are material. Furthermore, we wish to caution and advise readers that these statements are based on assumptions that may not materialize and may involve risks and uncertainties, many of which are beyond our control that could cause actual events or performance to differ materially from those contained or implied in these forward-looking statements.

Forward-looking statements are subject to a number of risks and uncertainties including, but not limited to, the risks inherent in our lack of profitability and need for additional capital to conduct our business; our dependence on partners to further the development of our product candidates; the uncertainties inherent in the development, attainment of the requisite regulatory authorizations and approvals (including EUA in the United States and CMA in the United Kingdom and European Union) and launch of any new pharmaceutical product; challenges associated with manufacturing and commercializing a biologic such as lenzilumab; and the outcome of pending or future litigation or arbitrations to which we are a party. Additional factors that could cause actual results to differ materially are the factors discussed under “Risk Factors” in our most recent Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and our other reports filed with the SEC. We also will include or incorporate by reference in each prospectus supplement important factors that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Should one or more known or unknown risks or uncertainties materialize, or should underlying assumptions prove inaccurate, actual results could differ materially from past results and those anticipated, estimated, projected or implied by these forward-looking statements. You should consider these factors and the other cautionary statements made in this prospectus, any prospectus supplement or the documents we incorporate by reference herein or therein as being applicable to all related forward-looking statements wherever they appear in this prospectus, any prospectus supplement or the documents incorporated by reference herein or therein. While we may elect to update forward-looking statements wherever they appear in this prospectus, any prospectus supplement or the documents incorporated by reference herein or therein, we do not assume, and specifically disclaim, any obligation to do so, whether as a result of new information, future events or otherwise, except as required by law. Because of these uncertainties, you should not place undue reliance on these forward-looking statements.

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Table of the trial, which willpre-screenContents subjects for EphA3 expression and assess the activity of KB004, in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) when confirmatory safety and pharmacokinetic data is obtained from the Phase 1 trial.

THE COMPANY

Overview

We are a clinical stage biopharmaceutical company, developing our portfolio of proprietary Humaneered^® anti-inflammatory immunology and immuno-oncology monoclonal antibodies. Our proprietary, patented Humaneered technology platform is a method for converting existing antibodies (typically murine) into engineered, high-affinity human antibodies designed for therapeutic use, particularly with acute and chronic conditions. We have developed or in-licensed targets or research antibodies, typically from academic institutions, and then applied our Humaneered technology to optimize them. Our lead product candidate, lenzilumab, and our other two product candidates, ifabotuzumab (“iFab”) and HGEN005, are Humaneered monoclonal antibodies. Our Humaneered antibodies are closer to human antibodies than chimeric or conventionally humanized antibodies and have a high affinity for their target. In addition, we believe our Humaneered antibodies offer further important advantages, such as high potency, a slow off-rate and a lower likelihood to induce an inappropriate immune response or infusion related reaction.

We are focusing our efforts on the development of our lead product candidate, lenzilumab. Lenzilumab is a monoclonal antibody that has been demonstrated to neutralize human granulocyte-macrophage colony-stimulating factor (“GM-CSF”), a cytokine that we believe is of critical importance in the hyperinflammatory cascade, sometimes referred to as cytokine release syndrome (“CRS”) or cytokine storm, associated with COVID-19, chimeric antigen receptor T-cell (“CAR-T”) therapy and acute Graft versus Host Disease (“aGvHD”) associated with bone marrow transplants.

Corporate Information

We were incorporated on March 15, 2000 in California and reincorporated as a Delaware corporation in September 2001. OurWe completed our initial public offering in January 2013. Effective August 7, 2017, we changed our legal name to Humanigen, Inc. We maintain a website at www.humanigen.com where you may obtain copies of our reports, information and proxy statements and other filings with the SEC as soon as they are filed. Information contained on our website is not part of this prospectus, and the inclusion of our website address in this prospectus is intended to be an inactive textual reference only. The address of our principal offices are located at 260 East Grand Avenue, South San Francisco, CA, 94080,executive office is 830 Morris Turnpike, 4^th Floor, Short Hills, New Jersey 07078 and our telephone number is (650) 243-3100. We maintain a website on the Internet at www.kalobios.com. Our website, and the information contained therein, is not a part of this prospectus.

The Securities We May Offer

We may offer up to $100,000,000 of common stock, warrants and/or units in one or more offerings and in any combination. This prospectus provides you with a general description of the securities we may offer. A prospectus supplement, which we will provide each time we offer securities, will describe the specific amounts, prices and terms of these securities.

Common Stock

Each holder of our common stock is entitled to one vote for each share on all matters to be voted upon by the stockholders, and there are no cumulative rights. Subject to any preferential rights of any outstanding preferred stock, holders of our common stock are entitled to receive ratably the dividends, if any, as may be declared from time to time by the board of directors out of funds legally available therefor. If there is a liquidation, dissolution or winding up of our company, holders of our common stock would be entitled to share in our assets remaining after the payment of liabilities and any preferential rights of any outstanding preferred stock.

Warrants

We may issue warrants for the purchase of common stock. We may issue warrants independently or together with other securities.

Units

We may issue units comprised of one or more of the other classes of securities issued by us as described in this prospectus in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit.(973) 200-3010.

 

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Table of Contents

RISK FACTORS

An investment

Investing in our securities involves a high degree of risk. The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in our securities. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk“Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under Item 1A, “Risk Factors,” in our most recent Annual Report on Form 10-K forand in any subsequently filed Quarterly Report on Form 10-Q, together with the fiscal year ended December 31, 2012, all of which are incorporated hereinrisk factors contained in our other SEC filings that we incorporate by reference andinto this prospectus or that may be amended, supplemented or superseded from time to time by other reports we file with the SECincluded in the future and any applicable prospectus supplement related to a particular offering.. The risks and uncertainties we have described are not the only ones we face.facing our company. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations.

FORWARD-LOOKING STATEMENTS

This prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement includes forward-looking statements. We have based theseforward-looking statements largely on our current expectations and projections about future events and financial trends affecting the financial condition of our business. Forward-looking statements should not be read as a guarantee of future performance or results, and will not necessarily be accurate indications of the times at, or by, which such performance or results will be achieved. Forward-looking statements are based on information available at the time those statements are made and/or management’s good faith belief as of that time with respect to future events, and are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in or suggested by the forward-looking statements.

Forward-looking statements include all statements that are not historical facts. In some cases, you can identify forward-looking statements by terms such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “anticipate,” “project,” “target,” “design,” “estimate,” “predict,” “potential,” “plan” or the negative of these terms, and similar expressions intended to identify forward-looking statements, and similar expressions and comparable terminology intended to identify forward-looking statements. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

our expectations regarding our expenses and revenue, the sufficiency of our cash resources and needs for additional financing;

our anticipated growth strategies;

our expectations regarding competition;

the anticipated trends and challenges in our business and the market in which we operate;

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the timing and success of preclinical studies and clinical trials conducted by us and our development partners, including the timing of Sanofi’s initiation of a Phase 2b clinical trial of our KB001-A product candidate for ventilator associated pneumonia (VAP) caused by Pseudomonas aeruginosa (Pa)(Pa VAP), and our expectations as to the timing of enrollment and availability of clinical data;

the ability to obtain and maintain regulatory approval of our product candidates, and the labeling for any approved products;

the scope, progress, expansion, and costs of developing and commercializing our product candidates;

the size and growth of the potential markets for our product candidates and the ability to serve those markets;

the rate and degree of market acceptanceoperations. The occurrence of any of our product candidates;

our abilitythese known or unknown risks might cause you to establish and maintain development partnerships;

our ability to attractlose all or retain key personnel;

our expectations regarding federal, state and foreign regulatory requirements;

regulatory developmentspart of your investment in the United States and foreign countries; and

offered securities.

 

our ability to obtain and maintain intellectual property protection for our product candidates.

Forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements.

Any forward-looking statement made by us in this prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement speaks only as of the date on which it is made. Except as required by law, we assume no obligation to update these statements publicly, or to update the reasons actual results could differ materially from those anticipated in these statements, even if new information becomes available in the future.

Unless required by U.S. federal securities laws, we do not intend to update any of these forward-looking statements to reflect circumstances or events that occur after the statement is made.

You should read this prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we willintend to use the net proceeds from sales of the sale of securities offered by described in this prospectus primarily to develop and advance our product candidates through clinical trials, as well as for general corporate purposes, which could include working capital, and general corporate purposes.

The amounts and timing of anycapital expenditures, will vary depending on: the type, number, costs, and results of the product candidate development programs which we are pursuing or may choose to pursue in the future; the scope, progress, expansion, costs, and results of our clinical trials; the amounts and timing of any contingent payments from Sanofi; competitive and technological developments;acquisitions and the raterepayment of growth, if any, of our business. Accordingly, unless otherwise indicated in the prospectus supplement, our management will have significant flexibility in applyingindebtedness outstanding from time to time. Pending these uses, the net proceeds of the offerings, and investors willmay also be relying on the judgment of our management regarding the application of these net proceeds. Pending the uses described above, we intend to invest the net proceeds from this offeringtemporarily invested in short-term interest-bearing, investment-grade securities.

DESCRIPTION OF CAPITALCOMMON STOCK

The following description summarizes

This section describes the most importantgeneral terms and provisions of our capital stock. Because it is only a summary, itcommon stock and does not contain allpurport to be complete. It is subject to, and qualified in its entirety by reference to, the information that may be important to you. For a complete description, you should refer toapplicable provisions of our amended and restated certificate of incorporation, as amended from time to time (as so amended, the “Charter”), and our second amended and restated bylaws which have been filed with(the “Bylaws”). We encourage you to read the SEC as exhibits to our registration statement of which this prospectus forms a part,Charter, the Bylaws and to the applicable provisions of the Delaware law.General Corporation Law, or the DGCL, for more information.

The prospectus supplement relating to any offering of common stock, or other securities convertible into or exchangeable or exercisable for common stock, will describe more specific terms of the offering of common stock or other securities, including the number of shares offered, the initial offering price and market price and dividend information. The prospectus supplement may provide information that is different from this prospectus. If the information in the prospectus supplement with respect to our common stock being offered differs from this prospectus, you should rely on the information in the prospectus supplement.

General

Our authorized capital stock consists of 47,500,000250,000,000 shares of which 225,000,000 shares shall be common stock, par value $0.001 per share, and 25,000,000 shares shall be preferred stock, par value of $0.001 per share.

As of August 30, 2013,February 16, 2022, there were 24,296,96265,329,177 shares of common stock outstanding, held by 81approximately 33 stockholders of record, although we believe that there mayto be a significantly larger number of beneficial owners of our common stock. We derived the numberstock, and no shares of stockholders by reviewing the listing of outstanding commonpreferred stock recorded by our transfer agent as of August 30, 2013.outstanding.

Common Stock

Each holder of our common stock is entitled to one vote for each share of common stock held on all matters submitted to a vote of the stockholders and there are no cumulative rights.stockholders. Holders of our common stock are entitled to receive ratably the dividends, if any, as may be declared from time to time by the board of directors out of funds legally available therefor. If there is a liquidation, dissolution or winding up of our company, holders of our common stock would be entitled to share in our assets remaining after the payment of liabilities. Holders of our common stock have no preemptive or conversion rights or other subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The outstanding shares of common stock are fully paid and non-assessable. Holders of shares of our common stock are not liable for further calls or to assessments by us. The rights, powers, preferences and privileges of holders of common stock would be subordinate to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock which our board of directors may designate and issue in the future. Certain of our existing holders of common stock have the right to require us to register their shares of common stock under the Securities Act in specified circumstances.

Listing

Our common stock is listed on The NASDAQ Globalthe Nasdaq Capital Market under the trading symbol “KBIO.” “HGEN”.

Transfer Agent and Registrar

The transfer agent and registrar for theour common stock is Computershare Trust Company, N.A. The transfer agent’s address is 250 Royall Street, Canton, Massachusetts 02021 and its telephone number is (800) 662-7232.

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Dividend Policy

We have never declared or paid any cash dividends on our capital stock, and we do not currently intend to pay any cash dividends on our common stock for the foreseeable future. We expect to retain future earnings, if any, to fund the development and growth of our business. Any future determination to pay dividends on our common stock will be at the discretion of our board of directors and will depend upon, among other factors, our financial condition, operating results, current and anticipated cash needs, plans for expansion and other factors that our board of directors may deem relevant.

Anti-Takeover Provisions of Our Charter Documents and Delaware Law

Some provisions of our Charter, our Bylaws and Delaware law and our amended and restated certificate of incorporation and amended and restated bylaws could make it more difficult to acquire our company by means of a tender offer, a proxy contest, or otherwise.

Our amended and restated bylawsBylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our board of directors or a committee of our board of directors. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, for a proposal to be timely submitted for consideration at an annual meeting, notice must be delivered to our secretary not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our Bylaws specify the requirements as to form and content of all stockholders’ notices. These provisions might preclude our stockholders from bringing matters before our annual meeting of stockholders or from making nominations for directors at our annual meeting of stockholders if the proper procedures are not followed.

Our amendedCharter and restated certificate of incorporation and amended and restated bylawsBylaws both provide that vacancies on our board of directors, including newly created directorships, may be filled only by a majority vote of directors then in office, and directors so chosen shall hold office for a term expiring at the next annual meeting of stockholders or until such director’s successor shall have been duly elected and qualified. Accordingly, the board of directors could prevent any stockholder from filling the new directorships with such stockholder’s own nominee.

Our Charter provides that, unless we consent in writing to the selection of an alternative forum, the Delaware Court of Chancery shall be the sole and exclusive forum for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our current or former directors, officers or other employees to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the Delaware General Corporation Law, our Charter or our Bylaws, or (iv) any action asserting a claim against us governed by the internal affairs doctrine; in all cases subject to the court having personal jurisdiction over the indispensable parties named as defendants. This choice of forum provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits against us and our directors, officers and other employees.

Delaware Anti-Takeover Law

We are subject to Section 203 of the Delaware General Corporation Law which contains anti-takeover provisions. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date that the person became an interested stockholder, unless the business combination or the transaction in which the person became an interested stockholder is approved in a prescribed manner. Generally, a business combination includes a merger, asset or stock sale or another transaction resulting in a financial benefit to the interested stockholder. An interested stockholder is a person who, together with affiliates and associates, owns 15% or more of the corporation’s voting stock. The existence of this provision may have an anti-takeover effect with respect to transactions that are not approved in advance by our board of directors, including discouraging attempts that might result in a premium over the market price fortfor the shares of common stock held by stockholders.

No Cumulative Voting

Under Delaware law, cumulative voting for the election of directors is not permitted unless a corporation’s certificate of incorporation authorizes cumulative voting. Our amended and restated certificate of incorporationCharter does not provide for cumulative voting in the election of directors. Cumulative voting allows a minority stockholder to vote a portion or all of its shares for one or more candidates for seats on our board of directors. Without cumulative voting, a minority stockholder will not be able to gain as many seats on our board of directors based on the number of shares of our stock the stockholder holds as compared to the number of seats the stockholder would be able to gain if cumulative voting were permitted. The absence of cumulative voting makes it more difficult for a minority stockholder to gain a seat on our board of directors to influence our board’s decision regarding a takeover.

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Stockholder Action by Written Consent

Delaware law generally provides that the affirmative vote of a majority of the shares entitled to vote on such matter is required to amend a corporation’s certificate of incorporation or bylaws, unless a corporation’s certificate of incorporation or bylaws requires a greater percentage. Our Charter permits our board of directors to amend or repeal most provisions of our Bylaws by majority vote. Generally, our Charter may be amended by holders of a majority of the voting power of the then outstanding shares of our capital stock entitled to vote. The stockholder vote or consent with respect to an amendment of our Charter or Bylaws would be in addition to any separate class vote that might in the future be required under the terms of any series of preferred stock that might be outstanding at the time such a proposed amendment were submitted to stockholders. Delaware law and the provisions of our Bylaws generally permit stockholders owning the requisite percentage of shares of common stock necessary to approve an amendment to our Charter and Bylaws to act by written consent in lieu of a meeting of our stockholders.

Limitation of Liability and Indemnification of Officers and Directors

Our Bylaws provide indemnification, including advancement of expenses, to the fullest extent permitted under applicable law to any person made or threatened to be made a party to any threatened, pending, or completed action, suit, or proceeding, whether civil, criminal, administrative, or investigative by reason of the fact that such person is or was a director or officer of the company, or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust, or other enterprise, including service with respect to an employee benefit plan. In addition, our Charter provides that our directors will not be personally liable to us or our stockholders for monetary damages for breaches of their fiduciary duty as directors, unless they violated their duty of loyalty to us or our shareholders, acted in bad faith, knowingly or intentionally violated the law, authorized illegal dividends or redemptions or derived an improper personal benefit from their action as directors. This provision does not limit or eliminate our rights or the rights of any stockholder to seek nonmonetary relief such as an injunction or rescission in the event of a breach of a director’s duty of care. In addition, this provision does not limit the directors’ responsibilities under Delaware law or any other laws, such as the federal securities laws. We have obtained insurance that insures our directors and officers against certain losses and which insures us against our obligations to indemnify the directors and officers. We also have entered into indemnification agreements with our directors and executive officers.

DESCRIPTION OF PREFERRED STOCK

Our Charter provides that we may issue up to 25,000,000 shares of preferred stock, par value $0.001 per share. As of the date of this prospectus, no shares of preferred stock were outstanding. Shares of preferred stock may be issued from time to time in one or more series, each of which will have such distinctive designation or title as shall be determined by our Board prior to the issuance of any shares thereof. Preferred stock will have such voting powers, full or limited, or no voting powers, and such preferences, privileges and relative, participating, optional or other special rights and such qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, voting rights, redemption rights, liquidation preference, sinking fund terms and the number of shares constituting any series or the designation of any series, as shall be stated in such resolution or resolutions providing for the issue of such class or series of preferred stock as may be adopted from time to time by the Board prior to the issuance of any shares thereof.

While we do not currently have any plans for the issuance of any shares of preferred stock, the issuance of such preferred stock could adversely affect the rights of the holders of common stock and, therefore, reduce the market price of the common stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock on the rights of holders of the common stock until the Board determines the specific rights of the holders of the preferred stock; however, these effects may include:

·

Restricting dividends on the common stock;

·

Diluting the voting power of the common stock;

·

Impairing the liquidation rights of the common stock; or

·

Delaying, deterring or preventing a change in control of the Company.

DESCRIPTION OF WARRANTS

General

We may issue, either separately or together with other securities, warrants for the purchase of our common stock. Warrantsany of the other types of securities that we may be issued independently or together with our common stock and may be attached to or separate from any offered securities. Each series ofsell under this prospectus.

The warrants will be issued under a separate warrant agreementagreements to be entered into between us and a bank or trust company, as warrant agent. Theagent, all to be set forth in the applicable prospectus supplement relating to any or all warrants in respect of which this prospectus is being delivered. Copies of the form of agreement for each warrant, agentwhich we refer to collectively as “warrant agreements,” including the forms of certificates representing the warrants, which we refer to collectively as “warrant certificates,” and reflecting the provisions to be included in such agreements that will act solely as our agent in connectionbe entered into with respect to the particular offerings of each type of warrant, will be filed with the warrants. SEC and incorporated by reference as exhibits to the registration statement of which this prospectus forms a part.

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The warrant agent will not have any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. This summary offollowing description sets forth certain general terms and provisions of the warrants is not complete. Forto which any prospectus supplement may relate. The particular terms of the warrants to which any prospectus supplement may relate and the extent, if any, to which the general provisions may apply to the warrants so offered will be described in the applicable prospectus supplement. To the extent that any particular terms of the warrants, warrant agreements or warrant certificates described in a prospectus supplement differ from any of the terms of a particular series of warrants,described below, then the terms described below will be deemed to have been superseded by that prospectus supplement. We encourage you should refer to read the prospectus supplement for that series of warrants and theapplicable warrant agreement and certificate for that particular series.additional information before you purchase any of our warrants.

General

The prospectus supplement relating to a particular series of warrants to purchase our common stock will describe the terms of the warrants in respect of which this prospectus is being delivered, as well as the related warrant agreement and warrant certificates, including the following:following, where applicable:

 

the title of the warrants;

the offering price for the warrants, if any;

the aggregate number of warrants;

the designation and terms of the common stock that

·

the principal amount of, or the number of, securities, as the case may be, purchasable upon exercise of each warrant and the initial price at which the principal amount or number of securities, as the case may be, may be purchased upon such exercise;

·

the designation and terms of the securities, if other than common stock, purchasable upon exercise of the warrants and of any securities, if other than common stock, with which the warrants are issued;

·

the procedures and conditions relating to the exercise of the warrants;

·

the date, if any, on and after which the warrants, and any securities with which the warrants are issued, will be separately transferable;

·

the offering price, if any, of the warrants;

·

the date on which the right to exercise the warrants will commence and the date on which that right will expire;

·

if applicable, a discussion of the material United States federal income tax considerations applicable to the exercise of the warrants;

·

whether the warrants represented by the warrant certificates will be issued in registered or bearer form and, if registered, where they may be transferred and registered;

·

call provisions, if any, of the warrants;

·

antidilution provisions, if any, of the warrants; and

·

any other material terms of the warrants.

The description in the prospectus supplement will not necessarily be complete and will be qualified in its entirety by reference to the warrant agreement and warrant certificate relating to the warrants being offered.

Exercise of Warrants

Each warrant will entitle the holder to purchase for cash that principal amount of, or number of, securities, as the case may be, at the exercise price set forth in, or to be determined as set forth in, the applicable prospectus supplement relating to the warrants. After the close of business on the expiration date, unexercised warrants will become void. Upon receipt of payment and the warrant certificate properly completed and duly executed, we will, as soon as practicable, issue the securities purchasable upon exercise of the warrants;

if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each security;

if applicable, the date from and after which the warrants and any securities issued with the warrants will be separately transferable;

the number of shares of common stock that may be purchased upon exercise of a warrant and the exercise price for the warrants;

the dates on which the right to exercise the warrants shall commence and expire;

if applicable, the minimum or maximum amountwarrant. If less than all of the warrants that mayrepresented by the warrant certificate are exercised, a new warrant certificate will be exercised at any one time;

issued for the remaining amount of warrants.

 

the currency or currency units in which the offering price, if any, and

No Rights of Security Holder Prior to Exercise

Before the exercise price are payable;

if applicable, a discussion of material U.S. federal income tax considerations;

the antidilution provisions of thetheir warrants, if any;

the redemption or call provisions, if any, applicable to the warrants;

any provisions with respect to the holder’s right to require us to repurchase the warrants upon a change in control or similar event; and

any additional terms of the warrants, including procedures, and limitations relating to the exchange, exercise and settlement of the warrants.

Holdersholders of warrants will not have any of the rights of holders of the securities purchasable upon the exercise of the warrants, and will not be entitled:entitled to, in the case of warrants to purchase equity securities, the right to vote or to receive dividend payments or similar distributions on the securities purchasable upon exercise.

 

to vote, consent or receive dividends;

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to receive notice as stockholders with respect to any meeting of stockholders for the election of our directors or any other matter; or

DESCRIPTION OF RIGHTS

 

As specified in the applicable prospectus supplement, we may issue rights to exercisepurchase the securities offered in this prospectus to our existing stockholders, and such rights may or may not be issued for consideration. The applicable prospectus supplement will describe the terms of any such rights. The description in the prospectus supplement will not purport to be complete and will be qualified in its entirety by reference to the documents pursuant to which such rights as stockholders of KaloBios.

will be issued.

DESCRIPTION OF UNITS

We may, from time to time, issue units consistingcomposed of any combinationone or more of the other types of securities that may be offered under this prospectus, in one or more series. We may evidenceany combination. Each unit will be issued so that the holder of the unit is also the holder of each seriessecurity included in the unit. Thus, the holder of units bya unit certificates that we will issue underhave the rights and obligations of a separate agreement.holder of each included security. We may enter into one or more unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicateThe unit agreement under which a unit is issued may provide that the name and address ofsecurities included in the unit agent, ifmay not be held or transferred separately at any in the applicabletime, or at any time before a specified date.

You should read any prospectus supplement relatingrelated to a particular series of units. This summary of certain provisions of the units is not complete. Forbeing offered, as well as the complete unit agreements that contain the terms of a particular series of units, you should refer to the prospectus supplement for that series of units and the unit agreement for that particular series. Specific unit agreements will contain additional important terms and provisions and weunits. We will file as an exhibit to the registration statement of which this prospectus isforms a part, or will incorporate by reference from another report that we file with the SEC, the form of each unit agreement relating to units offered under this prospectus.

Any applicable prospectus supplement may describe, among other things:

·

the material terms of the units and of the securities composing the units, including whether and under what circumstances those securities may be held or transferred separately;

·

any material provisions relating to the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units;

·

the date, if any, on and after which the constituent securities composing the units will be separately transferable;

·

any special United States federal income tax considerations applicable to the units; and

·

any material provisions of the governing unit agreement that differ from those described above.

FORMS OF SECURITIES

Each warrant, unit and right will be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Certificated securities will be issued in definitive form and global securities will be issued in registered form. Definitive securities name you or your nominee as the owner of the security, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable. Global securities name a depositary or its nominee as the owner of the warrants, rights or units represented by these global securities. The depositary maintains a computerized system that will reflect each investor’s beneficial ownership of the securities through an account maintained by the investor with its broker/dealer, bank, trust company or other representative, as we explain more fully below.

Registered Global Securities

We may issue the registered warrants, rights or units in the form of one or more fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement and registered in the name of that depositary or nominee. In those cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees.

If not described below, any specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement relating to those securities. We anticipate that the following provisions will apply to all depositary arrangements.

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Ownership of beneficial interests in a particular seriesregistered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may hold interests through participants. Upon the issuance of unitsa registered global security, the depositary will describecredit, on its book-entry registration and transfer system, the termsparticipants’ accounts with the respective principal or face amounts of the securities beneficially owned by the participants. Any dealers, underwriters or agents participating in the distribution of the securities will designate the accounts to be credited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by the depositary, with respect to interests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some states may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary, or its nominee, is the registered owner of a registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities represented by the registered global security for all purposes under the applicable warrant agreement, rights agreement or unit agreement. Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the applicable indenture, warrant agreement, unit agreement or rights agreement. Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any rights of a holder under the applicable warrant agreement, rights agreement or unit agreement. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the applicable warrant agreement, rights agreement or unit agreement, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Any payments to holders with respect to warrants, right or units includingrepresented by a registered global security registered in the following:name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of us, the warrant agents, the rights agents, the unit agents or any other agent of ours, agent of the trustees or agent of the warrant agents, rights agents or unit agents will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests.

We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment of any distribution of underlying securities or other property to holders on that registered global security, will immediately credit participants’ accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will issue securities in definitive form in exchange for the registered global security that had been held by the depositary. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or names that the depositary gives to the relevant warrant agent, rights agent, unit agent or other relevant agent of ours or theirs. It is expected that the depositary’s instructions will be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in the registered global security that had been held by the depositary.

 

the title of the series of units;

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identification and description of the separate constituent securities comprising the units;

the price or prices at which the units will be issued;

the date, if any, on and after which the constituent securities comprising the units will be separately transferable;

a discussion of certain United States federal income tax considerations applicable to the units; and

any other terms of the units and their constituent securities.

PLAN OF DISTRIBUTION

We may sell the securities being offered through this prospectus (1)hereby, from time to time, by one or more of the following methods:

·

to or through underwriting syndicates represented by managing underwriters;

·

through one or more underwriters without a syndicate for them to offer and sell to the public;

·

through dealers or agents;

·

in “at the market offerings”, within the meaning of Rule 415(a)(4) of the Securities Act, to or through a market maker or into an existing trading market on an exchange or otherwise;

·

in block trades; and

·

to investors directly in negotiated sales or in competitively bid transactions.

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing shareholders or other security holders. In some cases, we or dealers (2) directlyacting with us or on our behalf also may purchase securities and reoffer them to purchasers, includingthe public by one or more of the methods described above. This prospectus may be used in connection with any offering of our affiliates, (3)securities through agents,any of these methods or (4) through a combinationother methods described in the applicable prospectus supplement.

Any underwriter, agent or dealer involved in the offer and sale of any these methods. Theseries of the securities maywill be distributed at a fixed price or prices, which may be changed, market prices prevailing atnamed in the time of sale, prices related to the prevailing market prices, or negotiated prices. The prospectus supplement will include the following information:supplement.

 

the terms of the offering;

the names of any underwriters or agents;

the name or names of any managing underwriter or underwriters;

the purchase price of the securities;

the net proceeds from the sale of the securities;

any delayed delivery arrangements;

any underwriting discounts, commissions and other items constituting underwriters’ compensation;

any public offering price;

any discounts or concessions allowed or reallowed or paid to dealers; and

any commissions paid to agents.

Sale through underwriters or dealers

If underwriters are used in the sale, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. The underwritersWe may reselldistribute the securities from time to time in one or more transactions:

·

at fixed prices, which may be changed;

·

at market prices prevailing at the time of sale;

·

at varying prices determined at the time of sale; or

·

at negotiated prices.

Each prospectus supplement will set forth the manner and terms of an offering of securities, including:

·

whether that offering is being made to underwriters or through agents or directly;

·

the rules and procedures for any auction or bidding process, if used;

·

the securities’ purchase price or initial public offering price; and

·

the proceeds we anticipate from the sale of the securities.

In addition, we may enter into derivative or hedging transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. In connection with such a transaction, the third parties may sell securities covered by and pursuant to this prospectus and an applicable prospectus supplement or pricing supplement, as the case may be. If so, the third party may use securities borrowed from us or others to settle such sales and may use securities received from us to close out any related short positions. We also may loan or pledge securities covered by this prospectus and an applicable prospectus supplement to third parties, who may sell the loaned securities or, in an event of default in the case of a pledge, sell the pledged securities pursuant to this prospectus and the applicable prospectus supplement or pricing supplement, as the case may be.

In compliance with guidelines of the Financial Industry Regulatory Authority, or FINRA, the maximum consideration or discount to be received by any FINRA member or independent broker or dealer may not exceed 8% of the aggregate amount of the securities offered pursuant to this prospectus and any applicable prospectus supplement.

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Sales through Underwriters

If we use underwriters in the sale of some or all of the securities covered by this prospectus, the underwriters will acquire the securities for their own account. The underwriters may resell the securities, either directly to the public or to securities dealers, at various times in one or more transactions, including negotiated transactions. Underwriters may selltransactions, at a fixed public offering price or at varying prices determined at the securities in order to facilitate transactions in anytime of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicated in the prospectus supplement, thesale. The obligations of the underwriters to purchase the securities will be subject to certain conditions, andconditions. Unless indicated otherwise in a prospectus supplement, the underwriters will be obligated to purchase all the securities of the series offered securities if they purchase any of them. The underwriters may change from time to time anythe securities are purchased.

Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers. The prospectus supplement will include the names of the principal underwriters the respective amount of securities underwritten, the nature of the obligation of the underwriters to take the securities and the nature of any material relationship between an underwriter and us.dealers may be changed intermittently.

If dealers are used in the sale of securities offered

Sales through this prospectus, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The prospectus supplement will include the names of the dealers and the terms of the transaction.Agents

Direct sales and sales through agents

We may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such securities may also be sold through agents designated from time to time. The prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent by us. Unless otherwise indicated in the applicable prospectus supplement, anywhen securities are sold through an agent, the designated agent will agree, to use its reasonable best efforts to solicit purchases for the period of its appointment.

We mayappointment as agent, to use its best efforts to sell the securities directly to institutional investorsfor our account and will receive commissions from us as will be set forth in the applicable prospectus supplement.

Securities bought in accordance with a redemption or others whorepayment under their terms also may be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing by one or more firms acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the prospectus supplement. Remarketing firms may be deemed to be underwriters withinin connection with the meaning of the Securities Act with respect to any sale of those securities. The terms of any such sales will be describedsecurities they remarket.

If so indicated in the prospectus supplement.

Delayed delivery contracts

If theapplicable prospectus supplement, indicates, we maywill authorize agents, underwriters or dealers to solicit offers from certain types ofby specified institutions to purchase securities at the public offering price underset forth in the prospectus supplement pursuant to delayed delivery contracts. These contracts would provideproviding for payment and delivery on a future date specified date in the future. Theprospectus supplement. These contracts wouldwill be subject only to those conditions describedset forth in the prospectus supplement. The applicable prospectus supplement will describe the commission payable for solicitation of those contracts.

Market making, stabilization and other transactions

Unless the applicable prospectus supplement, states otherwise, each seriesand the prospectus supplement will set forth the commissions payable for the solicitation of the contracts.

Direct Sales

We may sell offered securities will be a new issue and will have no established trading market. We may elect to listdirectly as principal for our own account, without involving any series of offered securities on an exchange. Any underwriters thator agents.

Rights Offerings

If we use in the sale of offered securities may make a market in such securities, but may discontinue such market making at any time without notice. Therefore, we cannot assure you that the securities will have a liquid trading market.

Any underwriter may also engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Securities Exchange Act of 1934, as amended. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of theoffer securities in the open market after the distribution has been completed in ordera subscription rights offering to cover syndicate short positions.

Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

Derivative transactions and hedging

We, the underwritersour existing shareholders or other agents may engage in derivative transactions involving the securities. These derivatives may consist of short sale transactions and other hedging activities. The underwriters or agents may acquire a long or short position in the securities, hold or resell securities acquired and purchase options or futures on the securities and other derivative instruments with returns linked to or related to changes in the price of the securities. In order to facilitate these derivative transactions,security holders, we may enter into security lending or repurchase agreementsa standby underwriting agreement with dealers, acting as standby underwriters. We may pay the standby underwriters or agents. The underwriters or agents may effect the derivative transactions through sales ofa commitment fee for the securities they commit to the public, including short sales, or by lending the securities in orderpurchase on a standby basis. If we do not enter into a standby underwriting arrangement, we may retain a dealer-manager to facilitate short sale transactions by others. The underwriters or agents may also use the securities purchased or borrowed from us or others (or, in the case of derivatives, securities received from us in settlement of those derivatives) to directly or indirectly settle sales of the securities or close out any related open borrowings of the securities.manage a subscription rights offering for us.

Electronic auctions

We may also make salesSales through the Internet or through other electronic means. Since we may from

From time to time, elect towe may offer securities directly to the public, with or without the involvement of agents, underwriters or dealers, utilizingand may use the Internet or other forms ofanother electronic bidding or ordering systemssystem for the pricing and allocation of such securities, you should pay particular attention to the description of that system we will provide insecurities. Such a prospectus supplement.

Such electronic system may allow bidders to participate directly, participate, through electronic access to an auction site, by submitting conditional offers to buy that are subject to acceptance by us, and which may directly affect the price or other terms and conditions at which such securities are sold. These

Such a bidding or ordering systemssystem may

present to each bidder, on a so-called “real-time”real-time basis, relevant information to assist you in making a bid, such as the clearing spread at which the offering would be sold, based on the bids submitted, and whether a bidder’s individual bids would be accepted, proratedpro-rated or rejected.

Other pricing methods also may be used. Upon completion of such an electronic auction process, securities will be allocated based on prices bid, terms of bid or other factors.

The final offering price at which securities would be sold and the allocation of securities among bidders would be based in whole or in part on the results of the Internet or other electronic bidding process or auction. Many variations of the Internet auction or pricing and allocation systems are likely to be developed in the future, and we may use such systems in connection with the sale of securities. The specific rules of such an auction would be distributed to potential bidders in an applicable prospectus supplement.

If an offering is made using such a bidding or ordering system you should review the auction rules, as described in the prospectus supplement, for a more detailed description of the offering procedures.

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General informationInformation

Agents,

Broker-dealers, agents or underwriters may receive compensation in the form of discounts, concessions or commissions from us or the purchasers of securities for which such broker-dealers, agents or underwriters may act as agents or to which they may sell as principal, or both. The compensation to a particular broker-dealer might be in excess of customary commissions.

Underwriters, dealers and agents that participate in any distribution of the offered securities may be deemed “underwriters” within the meaning of the Securities Act, so any discounts or commissions they receive in connection with the distribution might be deemed to be underwriting compensation. Those underwriters and dealersagents may be entitled, under their agreements entered into with us, to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution by us to payments that they may be required to make in respect of those civil liabilities. Various of those underwriters or agents may be customers of, engage in transactions with, or perform services for, us or our affiliates in the ordinary course of business. We will identify any underwriters or agents, and describe their compensation, in a prospectus supplement.

We will file a supplement to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, if we enter into any material arrangement with a broker, dealer, agent or underwriter for the sale of securities through a block trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer. The prospectus supplement will disclose:

·

the name of any participating broker, dealer, agent or underwriter;

·

the number and type of securities involved;

·

the price at which such securities were sold;

·

any securities exchanges on which such securities may be listed;

·

the commissions paid or discounts or concessions allowed to any such broker, dealer, agent or underwriter where applicable; and

·

other facts material to the transaction.

To facilitate the offering of securities under this prospectus or an applicable prospectus supplement, some persons participating in the offering of the securities may engage in transactions that stabilize, maintain or otherwise affect the price of the securities during and after the offering of the securities. Specifically, if the applicable prospectus supplement permits, the underwriters of the securities may over-allot or otherwise create a short position in the securities for their own account by selling more of the securities than we have sold to them and may elect to cover any such short position by purchasing the securities in the open market.

In addition, the underwriters may stabilize or maintain the price of the securities by bidding for or purchasing the securities in the open market and may impose penalty bids, under which selling concessions allowed to syndicate members or other broker-dealers participating in the offering are reclaimed if securities previously distributed in the offering are repurchased in connection with stabilization transactions or otherwise. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. The imposition of a penalty bid also may affect the price of securities to the extent that it discourages resales of the securities. We make no representation as to the magnitude or effect of any such stabilization or other transactions. Such transactions, if commenced, may be discontinued at any time.

To comply with the securities laws of some states and other jurisdictions, if applicable, the securities must be sold in such jurisdictions only through registered or licensed brokers or dealers. In addition, in some states and other jurisdictions, the securities may not be sold unless they have been registered or qualified for sale in the jurisdiction or an exemption from the registration or qualification requirement is available and is complied with.

Rule 15c6-1 under the Exchange Act generally requires that trades in the secondary market settle in two business days, unless the parties to any such trade expressly agree otherwise. Your prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date before the second business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than two scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

This prospectus, the applicable prospectus supplement and any applicable pricing supplement in electronic format may be made available on the Internet sites of, or through other online services maintained by, us or one or more of the agents or dealers participating in an offering of securities, or by their affiliates. In those cases, prospective investors may be able to view offering terms online and, depending upon the particular agent to dealer, prospective investors may be allowed to place orders online.

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Other than this prospectus, the applicable prospectus supplement and any applicable pricing supplement in electronic format, the information on our web site or the web site of any agent or dealer and any information contained in any other web site maintained by any agent or dealer:

·

is not part of this prospectus, the applicable prospectus supplement and any applicable pricing supplement or the registration statement of which they form a part;

·

has not been approved or endorsed by us or by any agent or dealer in its capacity as an agent or dealer, except, in each case, with respect to the web site maintained by such entity; and

·

should not be relied upon by investors.

There can be no assurance that we will sell all or any of the securities offered by this prospectus.

This prospectus also may be used in connection with any issuance of shares of common stock or preferred stock upon exercise of a warrant if such an issuance is not exempt from the registration requirements of the Securities Act.

LEGAL MATTERS

The validity of the issuance of the securities offered by this prospectus will be passed upon for us by Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP, Redwood City, CA.Polsinelli PC, Washington, DC. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of KaloBios Pharmaceuticals,Humanigen, Inc. appearingas of December 31, 2021 and 2020 and for each of the years in the KaloBios Pharmaceuticals,two-year period ended December 31, 2021 and the effectiveness of internal control over financial reporting as of December 31, 2021 incorporated in this Prospectus by reference from the Humanigen, Inc. Annual Report on Form 10-K for the year ended December 31, 20122021 have been audited by Ernst & YoungHORNE LLP, an independent registered public accounting firm, as set forthstated in their reports thereon which report thereon, included therein,expresses an unqualified opinion and incorporated herein by reference. Such consolidated financial statements areincludes an explanatory paragraph relating to a going concern uncertainty, incorporated herein by reference in this Prospectus and Registration Statement in reliance upon such report given onreports and upon the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

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We file annual, quarterly and other reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. You may also read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, including any amendments to those reports, and other information that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge through the Internet. These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

We have filed with the SEC a registration statement under the Securities Act of 1933 relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus does not contain all of the information set forth in the registration statement. You can obtain a copy of the registration statement, at prescribed rates, from the SEC at the address listed above. The registration statement and the documents referred to below under “Information Incorporated by Reference” are also available on our Internet website, www.kalobios.com. We have not incorporated by reference into this prospectus the information on our website, and you should not consider it to be a part of this prospectus.

INFORMATION INCORPORATED BY REFERENCE

The SEC allows us to incorporate by reference into this prospectus certain information we file with it, which means that we can disclose important information by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the SEC will automatically update and supersede information contained in this prospectus is not complete and any accompanying prospectus supplement.may be changed. We incorporate by referencemay not sell these securities until the documents listed below that we have previously filed with the SEC (excluding any portions of any Form 8-K that are not deemed “filed” pursuant to the General Instructions of Form 8-K):

our Annual Report on Form 10-K for the year ended December 31, 2012 filed on April 1, 2013;

our Quarterly Report on Form 10-Q for the quarterly period ended on March 31, 2013 filed on April 29, 2013;

our Quarterly Report on Form 10-Q for the quarterly period ended on June 30, 2013 filed on August 19, 2013;

All information in our proxyregistration statement filed with the Securities and Exchange Commission on April 29, 2013 to the extent incorporated by reference in our Annual Report on Form 10-K for the year ended December 31, 2012;

Current Reports on Form 8-K (excluding any reports or portions thereof that are deemed to be furnished and not filed) filed on January 10, 2013, January 15, 2013, February 1, 2013, June 24, 2013, August 6, 2013 and August 8, 2013; and

the description of our common stock contained in our Registration Statement on Form 8-A as filed with the SEC on January 30, 2013 pursuant to Section 12(b) of the Exchange Act.

We also incorporate by reference into this prospectus additional documents that we may file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the completion or termination of the offering, including all such documents we may file with the SEC after the date of the initial registration statement and prior to the effectiveness of the registration statement, but excluding any information deemed furnished and not filed with the SEC. Any statements contained in a previously filed document incorporated by reference into thisis effective. This prospectus is deemednot an offer to be modifiedsell these securities and is not soliciting an offer to buy or superseded for purposes of this prospectus tosell these securities in any jurisdiction where the extent that a statement contained in this prospectus,offer or in a subsequently filed document also incorporated by reference herein, modifies or supersedes that statement.

This prospectus may contain information that updates, modifies orsale is contrary to information in one or more of the documents incorporated by reference in this prospectus. You should rely only on the information incorporated by reference or provided in this prospectus. We have not authorized anyone else to provide you with different information. You should not assume that the information in this prospectus is accurate as of any date other than the date of this prospectus or the date of the documents incorporated by reference in this prospectus.

We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus.

Requests for such documents should be directed to:

KaloBios Pharmaceuticals, Inc.

260 East Grand Avenue

South San Francisco, CA 94080

(650) 243-3100

You may also access the documents incorporated by reference in this prospectus through our website at www.kalobios.com. Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated in this prospectus or the registration statement of which it forms a part.

permitted.

 

$100,000,000SUBJECT TO COMPLETION, DATED MARCH 1, 2022

COMMON STOCK

WARRANTS

UNITS

PROSPECTUS

Up to $75,000,000

 

 

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The information in this prospectus is not complete and may be changed. We may not sell the securities pursuant to this prospectus until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

 

 

SUBJECT TO COMPLETION, DATED SEPTEMBER 3, 2013

PROSPECTUS

$50,000,000Common Stock

 

COMMON STOCK

We previously entered into a Controlled Equity Offering^SM Sales Agreement, or sales agreement, with Cantor Fitzgerald & Co., or Cantor Fitzgerald, relating to shares of our common stock, $0.001 par value per share, offered by this prospectus. In accordance with the terms of the At-the-Market Issuance Sales Agreement entered into with MLV & Co. LLC, or MLV, dated September 3, 2013, which we refersales agreement, from time to as the sales agreement,time we may offer and sell shares of our common stock par value $0.001 per share, having an aggregate offeringgross sales price of up to $50,000,000 from time to time$75,000,000 through MLV,Cantor Fitzgerald, acting as agent.sales agent, pursuant to this prospectus.

Our common stock is listed on The NASDAQ Globalthe Nasdaq Capital Market under the symbol “KBIO.“HGEN.” TheOn February 28, 2022, the last reported sale price of our common stock on August 30, 2013the Nasdaq Capital Market was $5.57$2.03 per share.

Sales of our common stock, if any, under this prospectus willmay be made by any method permitted that isin sales deemed to be an “at the market” offering“at-the-market offering” as defined in Rule 415415(a)(4) promulgated under the Securities Act of 1933, as amended, including by meansor the Securities Act. Subject to terms of ordinary brokers’ transactions at market prices, in block transactionsthe sales agreement, Cantor Fitzgerald is not required to sell any specific number or as otherwise agreed by MLV and us. MLVdollar amounts of securities but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices.practices, on mutually agreed terms between Cantor Fitzgerald and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

MLV

Cantor Fitzgerald will be entitled to compensation under the terms of the sales agreement at a fixed commission rate of 3%up to 3.0% of the gross sales price per share sold. In connection with the sale of theour common stock on our behalf, MLV mayCantor Fitzgerald will be deemed to be an “underwriter” within the meaning of the Securities Act of 1933, as amended, and the compensation of MLV mayCantor Fitzgerald will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contributioncontributions to MLV with respect toCantor Fitzgerald against certain civil liabilities, including liabilities under the Securities ActAct. See “Plan of 1933, as amended.

INVESTING IN THESE SECURITIES INVOLVES SIGNIFICANT RISKS. BEFORE BUYING SHARES OF OUR COMMON STOCK, YOU SHOULD CAREFULLY CONSIDER THERISK FACTORS BEGINNING ON PAGE 4 OF THIS PROSPECTUS AND IN THE DOCUMENTS INCORPORATED BY REFERENCE INTO THIS PROSPECTUS AND ANY FREE WRITING PROSPECTUS THAT WE HAVE AUTHORIZED FOR USE IN CONNECTION WITH THIS OFFERING.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.Distribution.”

 

The dateInvesting in our common stock involves risks. See “Risk Factors” on page 4 of this prospectus is                 , 2013

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TABLE OF CONTENTS

		Page
ABOUT THIS PROSPECTUS			1
PROSPECTUS SUMMARY			2
RISK FACTORS			4
FORWARD-LOOKING STATEMENTS			5
USE OF PROCEEDS			7
DILUTION			8
DIVIDEND POLICY			9
PLAN OF DISTRIBUTION			10
LEGAL MATTERS			11
EXPERTS			11
WHERE YOU CAN FIND ADDITIONAL INFORMATION			11
INFORMATION INCORPORATED BY REFERENCE			12

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ABOUT THIS PROSPECTUS

This prospectus relates to the offering of our common stock. Before buying any of the common stock that we are offering, we urge you to carefully read this prospectus, together with the information incorporated by reference as described under the heading “Where You Can Find Additional Information” and “Information Incorporated by Reference.” These documents contain important information that you should consider when making your investment decision.

This prospectus describes the specific terms of the common stock we are offering and also adds to and updates information contained in the documents incorporated by reference into this prospectus. To

Neither the extent thereSecurities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a conflict between the information contained incriminal offense.

Cantor

The date of this prospectus onis          , 2022

Table of Contents

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS	1
PROSPECTUS SUMMARY	2
RISK FACTORS	4
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	5
USE OF PROCEEDS	6
DILUTION	7
DESCRIPTION OF COMMON STOCK	8
PLAN OF DISTRIBUTION	10
LEGAL MATTERS	11
EXPERTS	11
WHERE YOU CAN FIND MORE INFORMATION	11
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE	11

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the one hand,U.S. Securities and Exchange Commission, or the information contained in any document incorporated by reference inSEC, utilizing a “shelf” registration process. By using a shelf registration statement, we may offer shares of our common stock having an aggregate offering price of up to $75,000,000 from time to time under this prospectus onpursuant to the other hand, you should rely on the information in this prospectus. sales agreement with Cantor Fitzgerald. 

If any statement in one of these documentsthis prospectus is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference intoin this prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

You should only rely on

We further note that the information contained or incorporatedrepresentations, warranties and covenants made by reference in this prospectus and any issuer free writing prospectus that we may authorize for use in connection with this offering. No person has been authorized to give any information or make any representations in connection with this offering other than those contained or incorporated by reference in this prospectus and any related issuer free writing prospectus in connection with the offering described herein and therein, and, if given or made, such information or representations must not be relied upon as having been authorized by us. Neither this prospectus nor any related issuer free writing prospectus shall constitute an offer to sell or a solicitation of an offer to buy offered securitiesus in any jurisdiction in which itagreement that is unlawful for such person to make suchfiled as an offering or solicitation. This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should referexhibit to the registration statement including its exhibits.

You should read the entire prospectus and any related issuer free writing prospectus, as well as the documents incorporated by reference intoof which this prospectus forms a part, or to any related issuer free writing prospectus, before making an investment decision. Neither the delivery of this prospectus or any issuer free writing prospectus nor any sale made hereunder shall under any circumstances implydocument that the information contained oris incorporated by reference herein, were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or in any issuer free writing prospectus is correctcovenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

We and Cantor Fitzgerald have not authorized anyone to provide you with any date subsequentinformation other than that contained in this prospectus. We and Cantor Fitzgerald take no responsibility for and can provide no assurance as to the date hereof orreliability of, such issuer free writing prospectus.any other information that others may give you. We are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. You should assume that the information appearing in this prospectus oris accurate as of the date on the cover of this prospectus, and that any documentinformation incorporated by reference is accurate only as of the date of the applicable documents,document incorporated by reference, regardless of the time of delivery of this prospectus or any sale or issuance of securities.a security, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference” in this prospectus.

For investors outside the United States: We and Cantor Fitzgerald have not done anything that date.

would permit this offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the shares of common stock and the distribution of this prospectus outside the United States.

When we refer to “Humanigen,” “we,” “our,” “us” and the “Company” in this prospectus, we mean Humanigen, Inc. and its subsidiaries on a consolidated basis, unless otherwise specified. References to “you” refer to a prospective investor.

This prospectus may include trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included in this prospectus are the property of their respective owners.

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PROSPECTUS SUMMARY

This summary descriptionhighlights certain information about us and our business highlightsthis offering and selected information contained elsewhere in this prospectus or incorporated inby reference into this prospectus by reference.prospectus. This summary is not complete and does not contain all of the information that you should consider before investing in our common stock. You should carefully read this entire prospectus and any issuer free writing prospectus, including each of the documents incorporated herein or therein by reference, and the information referred to under the heading “Risk Factors” in this prospectus beginning on page 4, before making an investment decision. As used in this prospectus, “we,” “us,” “KaloBios” and “our” refer to KaloBios Pharmaceuticals, Inc., a Delaware corporation.

KaloBios Pharmaceuticals, Inc.

Overview

We are a biopharmaceutical company focused on the development of monoclonal antibody therapeutics to treat serious medical conditions with a primary clinical focus on severe respiratory diseases and cancer. Using our proprietary and patented Humaneered^® antibody technology, we have produced a portfolio of patient-targeted, first-in-class, antibodies. We take a patient-targeted approach with each of our antibody programs by developing a new or utilizing an existing screen or diagnostic method that we believe may identify those individuals most likely to benefit from our therapies. We believe that antibodies produced with our Humaneered^® technology offer important clinical and economic advantages over antibodies generated by other methods, making our antibodies potentially more suitable for chronic treatment. We seek to identify and develop products that may treat multiple indications through proof-of-concept studies, and then secure development partnerships with large pharmaceutical and biotechnology companies who will further develop and commercialize our products while we retain rights in specialty or orphan indications.

We currently have three monoclonal antibodies at the clinical development stage:

•

Our first antibody, KB003 (a Humaneered®, recombinant, anti-granulocyte macrophage colony- stimulating factor (anti-GM-CSF) monoclonal antibody), is in a Phase 2 clinical trial in severe asthma patients inadequately controlled by corticosteroids. We plan to report data from this trial by early 2014. KB002, the chimeric precursor molecule to KB003, showed activity with a single dose in a Phase 1/2 clinical study in persistent asthma and in a Phase 1 clinical study in rheumatoid arthritis (RA).

•

Our second antibody, KB001-A (a Humaneered®, recombinant, PEGylated, anti-PcrV of Pseudomonas Fab’ antibody), is in clinical development for the prevention and treatment of infections caused by Pa, a gram-negative bacterium. Pa can cause chronic respiratory infections in individuals with cystic fibrosis (CF) and pneumonia in mechanically ventilated patients. Clinical trials in Pa VAP and CF patients infected with Pa were completed with a precursor molecule, KB001, that showed activity in Phase 1/2 clinical studies with a single dose for both indications.

KB001-A is in a Phase 2 clinical trial, conducted by us, in CF patients with chronic Pa lung infection. Clinical data are expected by the end of 2014. Our partner, Sanofi Pasteur (Sanofi), has an option to assume primary worldwide responsibility for developing and promoting KB001-A for Pa in CF or bronchiectasis patients after the completion of this Phase 2 clinical trial.

For the pneumonia prevention indication, Sanofi is conducting a Phase 1 clinical trial in healthy volunteers to evaluate higher doses than those previously tested. After completion of manufacturing process development and scale-up, Sanofi plans to conduct a Phase 2b trial in the first half of 2015 to determine the safety and efficacy of KB001-A in preventing Pa VAP. We understand that this Phase 2b and Phase 3 trial are being designed as pivotal trials and are intended to serve as a basis for registration of KB001-A in the prevention of Pa VAP.

RISK FACTORS

An investment in our common stock involves a high degree of risk. Before deciding whether to invest in our common stock,stock. For a more complete understanding of our company and this offering, we encourage you shouldto read and consider carefully consider the risks and uncertainties described below, together withmore detailed information in this prospectus, including the information incorporated by reference into this prospectus and the information contained in and incorporated by reference under the heading “Risk Factors” in our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2012page 4 of this prospectus, and our Quarterly Reports on Form 10-Q for the three-month periods ended March 31, 2013 and June 30, 2013, as updated or superseded by the risks and uncertainties described under similar headings in the other documents that are filed after the date hereof and incorporated by reference into this prospectus.

Overview

We are a clinical stage biopharmaceutical company, developing our portfolio of proprietary Humaneered^® anti-inflammatory immunology and immuno-oncology monoclonal antibodies. Our proprietary, patented Humaneered technology platform is a method for converting existing antibodies (typically murine) into engineered, high-affinity human antibodies designed for therapeutic use, particularly with acute and chronic conditions. We have developed or in-licensed targets or research antibodies, typically from academic institutions, and then applied our Humaneered technology to optimize them. Our lead product candidate, lenzilumab, and our other two product candidates, ifabotuzumab (“iFab”) and HGEN005, are Humaneered monoclonal antibodies. Our Humaneered antibodies are closer to human antibodies than chimeric or conventionally humanized antibodies and have a high affinity for their target. In addition, we believe our Humaneered antibodies offer further important advantages, such as high potency, a slow off-rate and a lower likelihood to induce an inappropriate immune response or infusion related reaction.

We are focusing our efforts on the development of our lead product candidate, lenzilumab. Lenzilumab is a monoclonal antibody that has been demonstrated to neutralize human granulocyte-macrophage colony-stimulating factor (“GM-CSF”), a cytokine that we believe is of critical importance in the hyperinflammatory cascade, sometimes referred to as cytokine release syndrome (“CRS”) or cytokine storm, associated with COVID-19, chimeric antigen receptor T-cell (“CAR-T”) therapy and acute Graft versus Host Disease (“aGvHD”) associated with bone marrow transplants.

Corporate Information

We were incorporated on March 15, 2000 in California and reincorporated as a Delaware corporation in September 2001. We completed our initial public offering in January 2013. Effective August 7, 2017, we changed our legal name to Humanigen, Inc. We maintain a website at www.humanigen.com where you may obtain copies of our reports, information and proxy statements and other filings with the SEC as soon as they are filed. Information contained on our website is not part of this prospectus, together with alland the inclusion of our website address in this prospectus is intended to be an inactive textual reference only. The address of our principal executive office is 830 Morris Turnpike, 4^th Floor, Short Hills, New Jersey 07078 and our telephone number is (973) 200-3010.

RISK FACTORS

Investing in our common stock involves a high degree of risk. You should carefully review the risks and uncertainties described below and discussed under the caption “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2021, as updated by our quarterly, annual and other information contained orreports and documents that are incorporated by reference into this prospectus, before deciding whether to purchase any common stock in this prospectusoffering. Each of the risk factors could adversely affect our business, operating results, financial condition and prospects, as well as adversely affect the value of an investment in our common stock, and the occurrence of any issuer free writing prospectus that we may authorize for use in connection with this offering. Theof these risks and uncertainties we have described are not the only ones we face.might cause you to lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deembelieve are immaterial may also affectsignificantly impair our business operations. Past financial performance

Risks Related to This Offering

We have broad discretion in how we use the net proceeds from this offering, and we may not be a reliable indicator of future performance, and historical trends should not be used to anticipate resultsuse these proceeds effectively or trends in future periods. If any of these risks actually occurs, our business, business prospects, financial condition or results of operations could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Forward-Looking Statements.”

Additional Risks Relating to this Offering

Our management team may invest or spend the proceeds of this offering in ways with which you mayagree.

We have not agree or in ways which may not yield a significant return.

designated any portion of the net proceeds from this offering to be used for any particular purpose. Our management will have broad discretion over the use of proceeds from this offering. The net proceeds from this offering will be used primarilyas to develop and advance our product candidates through clinical trials, as well as for working capital and general corporate purposes. However, our management will have broad discretion in the application of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of this offering. Our stockholders may not agree with the manner in which our management chooses to allocate and spend the net proceeds. Moreover, our management may use the net proceeds in waysfor corporate purposes that domay not improve our results of operations or enhanceincrease the valuemarket price of our common stock. See “Use of Proceeds” in this prospectus for more detailed information.

You may experience immediate and substantial dilution.

The failure by managementoffering price per share in this offering may exceed the net tangible book value per share of our common stock outstanding prior to apply these funds effectively could result in financial lossesthis offering. Assuming that could havean aggregate of 36,585,366 shares of our common stock are sold at a material adverse effect on our business, causeprice of $2.05 per share pursuant to this prospectus, which was the last reported sale price of our common stock to declineon the Nasdaq Capital Market on February 25, 2022, for aggregate gross proceeds of $75,000,000, after deducting commissions and delayestimated aggregate offering expenses payable by us, you would experience immediate dilution of $1.56 per share, representing the developmentdifference between the assumed offering price of $2.05 per share, which was the last reported sale price of our product candidates.common stock on the Nasdaq Capital Market on February 25, 2022, and our as adjusted net tangible book value per share as of December 31, 2021 after giving effect to this offering. The exercise of outstanding stock options and warrants may result in further dilution of your investment. See “Dilution” in this prospectus for a more detailed illustration of the dilution you would incur if you participate in this offering.

You may experience future dilution as a result of future equity offerings.

Because

In order to raise additional capital, we may in the prices per share at whichfuture offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by any investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders.

It is not possible to predict the aggregate proceeds resulting from sales made under the sales agreement.

Subject to certain limitations in the sales agreement and compliance with applicable law, we have the discretion to deliver a placement notice to Cantor Fitzgerald at any time throughout the term of the sales agreement. The number of shares that are sold through Cantor Fitzgerald after delivering a placement notice will fluctuate based on a number of factors, including the market price of our common stock during the sales period, any limits we may set with Cantor Fitzgerald in any applicable placement notice and the demand for our common stock. Because the price per share of each share sold pursuant to the sales agreement will fluctuate over time, it is not currently possible to predict the aggregate proceeds to be raised in connection with sales under the sales agreement.

The common stock offered hereby will be sold in an “at-the-market offering,” and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and accordingly may experience different levels of dilution and different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices and number of shares sold in this offering. In addition, subject to the final determination by our board of directors or any restrictions we may place in any applicable placement notice delivered to Cantor Fitzgerald, there is no minimum or maximum sales price for shares to be sold in this offering. Investors may experience a decline in the value of the shares they purchase in this offering may be substantially higheras a result of sales made at prices lower than the prices they paid.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference herein, may contain forward-looking statements that are based on management’s beliefs and assumptions and on information currently available to management. They can be identified by the use of forward-looking words, such as “anticipate,” “believe,” “could,” “estimate,” “expects,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” or the negative of these terms or other comparable expressions that convey uncertainty of future events or outcomes, although not all forward-looking statements contain these terms.

Forward-looking statements may include, but are not limited to, statements about our expectations regarding: our beliefs as to the potential benefits of lenzilumab as a treatment for hospitalized COVID-19 patients; the timeline for announcement of release of topline results from the ACTIV-5/BET-B study being conducted by the National Institutes of Health; our efforts and potential timeline to make future regulatory submissions in respect of potential emergency use authorization or other marketing authorization or approval from applicable regulatory agencies in the United States, United Kingdom, European Union and other foreign jurisdictions for commercial use of lenzilumab in COVID-19 patients; our other plans to initiate or participate in planned clinical trials and otherwise explore the effectiveness of lenzilumab and our other product candidates in our development portfolio as therapies for other inflammation and immune-oncology indications; our opportunity to benefit from various regulatory incentives; expectations for our financial results, revenue, operating expenses and other financial measures in future periods; the availability and adequacy of our sources of liquidity to satisfy our working capital needs, capital expenditures, and other liquidity requirements and continue as a going concern; and any statement that contains forward-looking words and other similar expressions.

The forward-looking statements included in this prospectus and the documents incorporated by reference herein reflect our current expectations and beliefs, and we do not undertake publicly to update or revise these statements, even if experience or future changes make it clear that any projected results expressed in this prospectus and the documents incorporated by reference herein will not be realized. In addition, the inclusion of any statement in this prospectus and the documents incorporated by reference herein does not constitute an admission by us that the events or circumstances described in such statement are material. Furthermore, we wish to caution and advise readers that these statements are based on assumptions that may not materialize and may involve risks and uncertainties, many of which are beyond our control that could cause actual events or performance to differ materially from those contained or implied in these forward-looking statements.

Forward-looking statements are subject to a number of risks and uncertainties including, but not limited to, the risks inherent in our lack of profitability and need for additional capital to conduct our business; our dependence on partners to further the development of our product candidates; the uncertainties inherent in the development, attainment of the requisite regulatory authorizations and approvals (including EUA in the United States and CMA in the United Kingdom and European Union) and launch of any new pharmaceutical product; challenges associated with manufacturing and commercializing a biologic such as lenzilumab; and the outcome of pending or future litigation or arbitrations to which we are a party. Additional factors that could cause actual results to differ materially are the factors discussed under “Risk Factors” in our most recent Annual Report on Form 10-K, and each subsequently filed Quarterly Report on Form 10-Q and our other reports filed with the SEC.

Should one or more known or unknown risks or uncertainties materialize, or should underlying assumptions prove inaccurate, actual results could differ materially from past results and those anticipated, estimated, projected or implied by these forward-looking statements. You should consider these factors and the other cautionary statements made in this prospectus or the documents we incorporate by reference herein or therein as being applicable to all related forward-looking statements wherever they appear in this prospectus, any prospectus supplement or the documents incorporated by reference. While we may elect to update forward-looking statements wherever they appear in this prospectus or the documents incorporated by reference, we do not assume, and specifically disclaim, any obligation to do so, whether as a result of new information, future events or otherwise, except as required by law. Because of these uncertainties, you should not place undue reliance on these forward-looking statements.

USE OF PROCEEDS

We may issue and sell shares of our common stock having aggregate sales proceeds of up to $75,000,000 from time to time. Because there is no minimum offering amount required pursuant to the sales agreement with Cantor Fitzgerald, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. Actual net proceeds will depend on the number of shares we sell and the prices at which such sales occur. There can be no assurance that we will sell any shares under or fully utilize the sales agreement with Cantor Fitzgerald as a source of financing.

We intend to use any net proceeds realized from the sales agreement with Cantor Fitzgerald principally for general corporate purposes, which could include working capital, capital expenditures, acquisitions and the repayment of indebtedness outstanding from time to time. Our expected use of net proceeds, if any, from the sale of shares of common stock pursuant to the sales agreement with Cantor Fitzgerald represents our intentions based upon our present plans and business conditions, which could change in the future as our plans and business conditions evolve. The amount and timing of our actual expenditures will depend upon numerous factors, including the results of our research and development efforts, the timing and success of preclinical studies and clinical trials we may commence in the future, the timing of regulatory submissions and the feedback from regulatory authorities. We have not determined the amount of net proceeds to be used specifically for such purposes and, as a result, management will retain broad discretion over the allocation of net proceeds, if any.

Pending use of the proceeds as described above, we intend to invest the proceeds in a variety of capital preservation investments, including short-term, investment-grade, interest-bearing instruments and U.S. government securities.

DILUTION

If you invest in our common stock in this offering, your ownership interest will be diluted immediately to the extent of the difference between the public offering price per share and the as adjusted net tangible book value per share of our common stock you may suffer immediate and substantial dilution inafter this offering.

Our net tangible book value as of December 31, 2021 was approximately $(23.7) million, or $(0.37) per share of common stock. Our net tangible book value is the amount of our total tangible assets less our total liabilities. Net tangible book value per share is our net tangible book value divided by the number of shares of common stock outstanding as of December 31, 2021. We calculate net tangible book value per share by dividing the net tangible book value by the number of outstanding shares of our common stock. Dilution with respect to net tangible book value per share represents the difference between the portion of the amount per share paid by purchasers of shares in this offering and the as adjusted net tangible book value per share of our common stock you purchaseimmediately after giving effect to this offering.

After giving effect to the assumed sale by us of shares of our common stock in the aggregate amount of $75,000,000 in this offering at an assumed offering price of $2.05 per share, which was the last reported sale price of our common stock on the Nasdaq Capital Market on February 25, 2022, and after deducting commissions and estimated aggregate offering expenses payable by us, our as adjusted net tangible book value as of December 31, 2021 would have been approximately $49.2 million, or $0.49 per share of common stock. This amount represents an immediate increase in net tangible book value per share of $0.86 to our existing stockholders and an immediate dilution in net tangible book value per share of $1.56 to new investors purchasing common stock in this offering. The following table illustrates this dilution on a per share basis to new investors participating in this offering.

The table above assumes, for illustrative purposes, that an aggregate of 36,585,366 shares of our common stock are sold at a price of $2.05 per share, the last reported sale price of our common stock on the Nasdaq Capital Market on February 25, 2022, for aggregate gross proceeds of $75,000,000. The shares sold in this offering, if any, will be sold from time to time at various prices. After giving effect to the saleAn increase of our common stock$1.00 per share in the maximum aggregate offering amount of $50,000,000price at anwhich the shares are sold from the assumed offering price of $5.57$2.05 per share the last reported sale price of our common stock on The NASDAQ Global Market on August 30, 2013, and after deducting estimated offering commissions payable by us, our net tangible book value as of June 30, 2013 would have been $97.3 million, or $2.93 per share of common stock. This represents an immediate increaseshown in the net tangible book value of $0.90 per share to our existing stockholders and an immediate and substantial dilution in net tangible book value of $2.64 per share to new investors who purchase our common stock in the offering. See “Dilution” for a more detailed discussion of the dilution you may incur in connection with this offering.

FORWARD-LOOKING STATEMENTS

This prospectus and the information incorporated by reference in this prospectus include forward-looking statements. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends affecting the financial condition of our business. Forward-looking statements should not be read as a guarantee of future performance or results, and will not necessarily be accurate indications of the times at, or by, which such performance or results will be achieved. Forward-looking statements are based on information available at the time those statements are made and/or management’s good faith belief as of that time with respect to future events, and are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in or suggested by the forward-looking statements.

Forward-looking statements includetable above, assuming all statements that are not historical facts. In some cases, you can identify forward-looking statements by terms such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “anticipate,” “project,” “target,” “design,” “estimate,” “predict,” “potential,” “plan” or the negative of these terms, and similar expressions intended to identify forward-looking statements, and similar expressions and comparable terminology intended to identify forward-looking statements. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

Forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements.

Any forward-looking statement made by us in this prospectus and the information incorporated by reference in this prospectus speaks only as of the date on which it is made. Except as required by law, we assume no obligation to update these statements publicly, or to update the reasons actual results could differ materially from those anticipated in these statements, even if new information becomes available in the future.

Unless required by U.S. federal securities laws, we do not intend to update any of these forward-looking statements to reflect circumstances or events that occur after the statement is made.

You should read this prospectus and the information incorporated by reference in this prospectus completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

USE OF PROCEEDS

The amount of proceeds from this offering will depend upon the number of shares of our common stock sold and the market price at which they are sold. There can be no assurance that we will be able to sell any shares under or fully utilize the sales agreement with MLV as a source of financing.

We will use the net proceeds from the sale of our common stock offered by this prospectus primarily to develop and advance our product candidates through clinical trials, as well as for working capital and general corporate purposes.

The amounts and timing of any expenditures will vary depending on: the type, number, costs, and results of the product candidate development programs which we are pursuing or may choose to pursue in the future; the scope, progress, expansion, costs, and results of our clinical trials; the amounts and timing of any contingent payments from Sanofi; competitive and technological developments; and the rate of growth, if any, of our business. Accordingly, our management will have significant flexibility in applying the net proceeds of the offerings, and investors will be relying on the judgment of our management regarding the application of these net proceeds. Pending the uses described above, we intend to invest the net proceeds from this offering in short-term, interest-bearing, investment-grade securities.

DILUTION

If you invest in our common stock, your interest will be diluted to the extent of the difference between the price per share you pay in this offering and the net tangible book value per share of our common stock immediately after this offering. Our net tangible book value of our common stock as of June 30, 2013 was approximately $49.1 million, or approximately $2.03 per share of common stock based upon 24,219,456 shares outstanding at that time. Net tangible book value per share is equal to our total tangible assets, less our total liabilities, divided by the total number of shares outstanding as of June 30, 2013.

After giving effect to the sale of our common stock in the aggregate amount of $50,000,000$75,000,000 during the term of the sales agreement with Cantor Fitzgerald is sold at anthat price, would increase our as adjusted net tangible book value per share after the offering to $0.55 per share and would increase the dilution in as adjusted net tangible book value per share to new investors to $2.50 per share, after deducting commissions and estimated aggregate offering expenses payable by us. A decrease of $1.00 per share in the price at which the shares are sold from the assumed offering price of $5.57$2.05 per share shown in the last reported sale pricetable above, assuming all of our common stock on The NASDAQ Global Market on August 30, 2013, and after deducting estimated offering commissions payable by us,in the aggregate amount of $75,000,000 during the term of the sales agreement with Cantor Fitzgerald is sold at that price, would decrease our as adjusted net tangible book value as of August 30, 2013 would have been $97.3 million, or $2.93 per share after the offering to $0.36 per share and would decrease the dilution in as adjusted net tangible book value per share to new investors to $0.69 per share, after deducting commissions and estimated aggregate offering expenses payable by us. This information is supplied for illustrative purposes only and may differ based on the actual offering price and the actual number of shares offered.

The number of common stockshares to be outstanding upon completion of this offering is based on 33,196,11764,027,629 shares of common stock outstanding on a pro forma basis at that time. This represents an immediate increase in net tangible book value of $0.90 per share to our existing stockholders and an immediate dilution in net tangible book value of $2.64 per share to new investors in this offering.

The following table illustrates this calculation on a per share basis as of June 30, 2013:

The foregoing table does not give effect to the exercise of any outstanding options or warrants. To the extent options and warrants are exercised, there may be further dilution to new investors.

December 31, 2021. The number of shares of our common stock to be outstanding immediately after this offering excludes:

To the extent that outstanding options or warrants are exercised or amounts under our loan and security agreement are converted, investors purchasing shares in this offering could experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

DESCRIPTION OF COMMON STOCK

This section describes the general terms and provisions of our common stock and does not purport to be complete. It is subject to, and qualified in its entirety by reference to, the applicable provisions of our amended and restated certificate of incorporation, as amended from time to time (as so amended, the “Charter”), and our second amended and restated bylaws (the “Bylaws”). We encourage you to read the Charter, the Bylaws and the applicable provisions of the Delaware General Corporation Law, or the DGCL, for more information.

General

Our authorized capital stock consists of 250,000,000 shares of which 225,000,000 shares shall be common stock, par value $0.001 per share, and 25,000,000 shares shall be preferred stock, par value of $0.001 per share.

As of February 16, 2022, there were 65,329,177 shares of common stock outstanding, held by approximately 33 stockholders of record, although we believe there to be a significantly larger number of beneficial owners of our common stock, and no shares of preferred stock outstanding.

Common Stock

Each holder of our common stock is entitled to one vote for each share of common stock held on all matters submitted to a pro forma basisvote of the stockholders. Holders of our common stock are entitled to receive ratably the dividends, if any, as may be declared from time to time by the board of directors out of funds legally available therefor. If there is based on 24,219,456a liquidation, dissolution or winding up of our company, holders of our common stock would be entitled to share in our assets remaining after the payment of liabilities. Holders of our common stock have no preemptive or conversion rights or other subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The outstanding shares of common stock are fully paid and non-assessable. Holders of shares of our common stock outstanding asare not liable for further calls or to assessments by us. The rights, powers, preferences and privileges of June 30, 2013holders of common stock would be subordinate to, and excludes:may be adversely affected by, the rights of the holders of shares of any series of preferred stock which our board of directors may designate and issue in the future. Certain of our existing holders of common stock have the right to require us to register their shares of common stock under the Securities Act in specified circumstances.

Listing

Our common stock is listed on the Nasdaq Capital Market under the trading symbol “HGEN”.

DIVIDEND POLICYTransfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent’s address is 250 Royall Street, Canton, Massachusetts 02021 and its telephone number is (800) 662-7232.

Dividend Policy

We have never declared or paid any cash dividends on our capital stock, and we do not currently intend to pay any cash dividends on our common stock for the foreseeable future. We expect to retain future earnings, if any, to fund the development and growth of our business. Any future determination to pay dividends on our common stock will be at the discretion of our board of directors and will depend upon, among other factors, our financial condition, operating results, current and anticipated cash needs, plans for expansion and other factors that our board of directors may deem relevant.

Anti-Takeover Provisions of Our Charter Documents and Delaware Law

Some provisions of our Charter, our Bylaws and Delaware law could make it more difficult to acquire our company by means of a tender offer, a proxy contest, or otherwise.

Our Bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our board of directors or a committee of our board of directors. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, for a proposal to be timely submitted for consideration at an annual meeting, notice must be delivered to our secretary not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our Bylaws specify the requirements as to form and content of all stockholders’ notices. These provisions might preclude our stockholders from bringing matters before our annual meeting of stockholders or from making nominations for directors at our annual meeting of stockholders if the proper procedures are not followed.

Our Charter and Bylaws both provide that vacancies on our board of directors, including newly created directorships, may be filled only by a majority vote of directors then in office, and directors so chosen shall hold office for a term expiring at the next annual meeting of stockholders or until such director’s successor shall have been duly elected and qualified. Accordingly, the board of directors could prevent any stockholder from filling the new directorships with such stockholder’s own nominee.

Our Charter provides that, unless we consent in writing to the selection of an alternative forum, the Delaware Court of Chancery shall be the sole and exclusive forum for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our current or former directors, officers or other employees to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the Delaware General Corporation Law, our Charter or our Bylaws, or (iv) any action asserting a claim against us governed by the internal affairs doctrine; in all cases subject to the court having personal jurisdiction over the indispensable parties named as defendants. This choice of forum provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits against us and our directors, officers and other employees.

Delaware Anti-Takeover Law

We are subject to Section 203 of the Delaware General Corporation Law which contains anti-takeover provisions. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date that the person became an interested stockholder, unless the business combination or the transaction in which the person became an interested stockholder is approved in a prescribed manner. Generally, a business combination includes a merger, asset or stock sale or another transaction resulting in a financial benefit to the interested stockholder. An interested stockholder is a person who, together with affiliates and associates, owns 15% or more of the corporation’s voting stock. The existence of this provision may have an anti-takeover effect with respect to transactions that are not approved in advance by our board of directors, including discouraging attempts that might result in a premium over the market price for the shares of common stock held by stockholders.

No Cumulative Voting

Under Delaware law, cumulative voting for the election of directors is not permitted unless a corporation’s certificate of incorporation authorizes cumulative voting. Our Charter does not provide for cumulative voting in the election of directors. Cumulative voting allows a minority stockholder to vote a portion or all of its shares for one or more candidates for seats on our board of directors. Without cumulative voting, a minority stockholder will not be able to gain as many seats on our board of directors based on the number of shares of our stock the stockholder holds as compared to the number of seats the stockholder would be able to gain if cumulative voting were permitted. The absence of cumulative voting makes it more difficult for a minority stockholder to gain a seat on our board of directors to influence our board’s decision regarding a takeover.

Stockholder Action by Written Consent

Delaware law generally provides that the affirmative vote of a majority of the shares entitled to vote on such matter is required to amend a corporation’s certificate of incorporation or bylaws, unless a corporation’s certificate of incorporation or bylaws requires a greater percentage. Our Charter permits our board of directors to amend or repeal most provisions of our Bylaws by majority vote. Generally, our Charter may be amended by holders of a majority of the voting power of the then outstanding shares of our capital stock entitled to vote. The stockholder vote or consent with respect to an amendment of our Charter or Bylaws would be in addition to any separate class vote that might in the future be required under the terms of any series of preferred stock that might be outstanding at the time such a proposed amendment were submitted to stockholders. Delaware law and the provisions of our Bylaws generally permit stockholders owning the requisite percentage of shares of common stock necessary to approve an amendment to our Charter and Bylaws to act by written consent in lieu of a meeting of our stockholders.

Limitation of Liability and Indemnification of Officers and Directors

Our Bylaws provide indemnification, including advancement of expenses, to the fullest extent permitted under applicable law to any person made or threatened to be made a party to any threatened, pending, or completed action, suit, or proceeding, whether civil, criminal, administrative, or investigative by reason of the fact that such person is or was a director or officer of the company, or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust, or other enterprise, including service with respect to an employee benefit plan. In addition, our Charter provides that our directors will not be personally liable to us or our stockholders for monetary damages for breaches of their fiduciary duty as directors, unless they violated their duty of loyalty to us or our shareholders, acted in bad faith, knowingly or intentionally violated the law, authorized illegal dividends or redemptions or derived an improper personal benefit from their action as directors. This provision does not limit or eliminate our rights or the rights of any stockholder to seek nonmonetary relief such as an injunction or rescission in the event of a breach of a director’s duty of care. In addition, this provision does not limit the directors’ responsibilities under Delaware law or any other laws, such as the federal securities laws. We have obtained insurance that insures our directors and officers against certain losses and which insures us against our obligations to indemnify the directors and officers. We also have entered into indemnification agreements with our directors and executive officers.

PLAN OF DISTRIBUTION

We have entered into an At-the-Market Issuancea Controlled Equity Offering^SM Sales Agreement, or sales agreement, with MLVCantor Fitzgerald & Co., or Cantor Fitzgerald, on December 31, 2020, under which from time to time we may issue and sell up to $50,000,000 worthshares of our common stock from timehaving an aggregate gross sales price of up to time under this prospectus. MLV will act$75,000,000 through Cantor Fitzgerald acting as agent inagent. Sales of the offering,shares of common stock, if any, may be made on the Nasdaq Capital Market at market prices and such other sales as agreed upon by us and Cantor Fitzgerald.

Upon delivery of a placement notice and subject to certain limitations, including the numberterms and conditions of shares registered under the registration statement to which the offering relates.

The sales, if any, of shares made under the sales agreement, will be madeCantor Fitzgerald may offer and sell shares of our common stock by any method that ispermitted by law deemed to be an “at the market” offering“at-the-market offering” as defined in Rule 415415(a)(4) promulgated under the Securities Act, including by means of ordinary brokers’ transactions at market prices, in block transactions or as otherwise agreed by MLV and us.Act. We may instruct MLVCantor Fitzgerald not to sell common stock if the sales cannot be effected at or above the price designated by us from time to time. We or MLVCantor Fitzgerald may suspend theor terminate this offering of our common stock upon notice and subject to other conditions. As an agent, MLV will not engage in any transactions that stabilize the price of our common stock.

Each time we wish to issue and sell common stock under the sales agreement, we will notify MLV of the number of shares to be issued, the dates on which such sales are anticipated to be made, any minimum price below which sales may not be made and other sales parameters as we deem appropriate. Once we have so instructed MLV, unless MLV declines to accept the terms of the notice, MLV has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such shares up to the amount specified on such terms. The obligations of MLV under the sales agreement to sell our common stock is subject to a number of conditions that we must meet.

We will pay MLVCantor Fitzgerald commissions, in cash, for its services in acting as sales agent in the sale of our common stock. MLVCantor Fitzgerald will be entitled to a commission of up to 3%3.0% of the gross sales price per share sold under the sales agreement. Because there is no minimum offering amount required as a condition to this offering, the actual total public offering amount, commissions and proceeds from the sale of common stock offered hereby. In addition, we have agreed to reimburse certain expenses of MLV in an amountus, if any, are not to exceed $25,000.determinable at this time. We estimate that the total expenses for the offering, excluding compensationcommissions payable to MLVCantor Fitzgerald under the terms of the sales agreement, will be approximately $300,000.$200,000.

Settlement for sales of shares of our common stock will occur on the third businesssecond trading day following the date on which any sales are made (or such earlier day as is industry practice for regular-way trading), or on some other date that is agreed upon by us and MLVCantor Fitzgerald in connection with a particular transaction, in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement. Sales of our common stock as contemplated in this prospectus will be settled through the facilities of The Depository Trust Company or by such other means as we and Cantor Fitzgerald may agree upon.

Cantor Fitzgerald will act as our sales agent and use commercially reasonable efforts, consistent with its normal trading and sales practices. In connection with the sale of the common stock on our behalf, MLV may, andCantor Fitzgerald will with respect to sales effected in an “at the market” offering, be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of MLV mayCantor Fitzgerald will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to MLVCantor Fitzgerald against certain civil liabilities, including liabilities under the Securities Act. We have also agreed to reimburse MLV for certain other specified expenses.

The offering of shares of our common stock pursuant to the sales agreement will terminate upon the earlier of (1) the sale of all shares of our common stock subject to the sales agreement, or (2) termination of the sales agreement as permitted undertherein. We and Cantor Fitzgerald may each terminate the sales agreement.agreement at any time upon ten days’ prior notice.

MLV

Cantor Fitzgerald and its affiliates may in the future provide various investment banking, commercial banking and other financial services for us and our affiliates, for which services they may in the future receive customary fees. To the extent required by Regulation M, MLVCantor Fitzgerald will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus.

This prospectus in electronic format may be made available on a website maintained by Cantor Fitzgerald and Cantor Fitzgerald may distribute this prospectus electronically.

LEGAL MATTERS

The validity of the securitiesissuance of the common stock offered by this prospectus will be passed upon for us by Gunderson Dettmer Stough Villeneuve FranklinPolsinelli PC, Washington, DC. Cantor Fitzgerald & Hachigian, LLP, Redwood City, CA. LeClairRyan, A Professional Corporation, New York, NY,Co. is counsel for MLVbeing represented in connection with this offering.offering by Goodwin Procter LLP, New York, New York.

EXPERTS

The consolidated financial statements of KaloBios Pharmaceuticals,Humanigen, Inc. appearingas of December 31, 2021 and 2020 and for each of the years in the KaloBios Pharmaceuticals,two-year period ended December 31, 2021 and the effectiveness of internal control over financial reporting as of December 31, 2021 incorporated in this Prospectus by reference from the Humanigen, Inc. Annual Report on Form 10-K for the year ended December 31, 20122021 have been audited by Ernst & YoungHORNE LLP, an independent registered public accounting firm, as set forthstated in their reports thereon which report thereon, included therein,expresses an unqualified opinion and incorporated herein by reference. Such consolidated financial statements areincludes an explanatory paragraph relating to a going concern uncertainty, incorporated herein by reference in this Prospectus and Registration Statement in reliance upon such report given onreports and upon the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND ADDITIONALMORE INFORMATION

We file annual, quarterly and othercurrent reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. You may also readThe SEC maintains a website that contains reports, proxy and copy any document weinformation statements and other information regarding issuers that file at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please callelectronically with the SEC at 1-800-SEC-0330 for furtherhttp://www.sec.gov.

Our website address is www.humanigen.com. The information contained on, the Public Reference Room. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, including any amendments to those reports, and other informationor that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed freethrough, our website is not a part of charge through the Internet. These filings will be available as soon as reasonably practicable after we electronically file such material with,this prospectus or furnish it to, the SEC.

We have filed with the SEC a registration statement under the Securities Act of 1933 relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus does not contain all of the information set forth in the registration statement. You can obtain a copy of the registration statement, at prescribed rates, from the SEC at the address listed above. The registration statement and the documents referred to below under “Information Incorporated by Reference” are also available on our Internet website, www.kalobios.com. We have not incorporated by reference into this prospectus or any prospectus supplement. We have included our website address as an inactive textual reference only.

This prospectus is part of a registration statement we filed with the SEC. This prospectus omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information onand exhibits in the registration statement for further information about us and our website,consolidated subsidiary and you shouldthe securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not consider itintended to be a part of this prospectus.

INCORPORATION OF CERTAIN INFORMATION INCORPORATED BY REFERENCE

The SEC allows us to incorporate by reference into this prospectus certainmuch of the information we file with it,the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information incorporatedthat we incorporate by reference in this prospectus is considered to be a part of this prospectus, and information thatprospectus. Because we file laterare incorporating by reference future filings with the SEC, will automatically updatethis prospectus is continually updated and those future filings may modify or supersede some of the information containedincluded or incorporated in this prospectus. WeThis means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus or in any document previously incorporated by reference herein or therein have been modified or superseded. This prospectus incorporates by reference the documents listed below that(File No. 001-35798) and any future filings we have previously filed with the SEC (excluding any portions of any Form 8-K that are not deemed “filed” pursuant to the General Instructions of Form 8-K):

We also incorporate by reference into this prospectus additional documents that we may filemake with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior(in each case, other than those documents or the portions of those documents not deemed to be filed) until the completion or terminationoffering of the offering,securities offered hereby is terminated or completed:

We also incorporate by reference into this prospectus all suchreports and other documents we may file withpursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus until the offering of the shares covered by this prospectus or the sale of shares by us pursuant to this prospectus has been terminated or completed, other than any portion of the respective filings that are furnished, rather than filed, under the applicable SEC rules. In addition, all reports and other documents we may file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of the initial registration statement of which this prospectus forms a part, and prior to the effectiveness of thesuch registration statement, but excluding any information deemed furnished and not filed with the SEC. Any statements contained in a previously filed document incorporated by reference into this prospectus is deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, or in a subsequently filed document also incorporated by reference herein, modifies or supersedes that statement.

This prospectus may contain information that updates, modifies or is contrary to information in one or more of the documents incorporated by reference in this prospectus. You should rely only on the information incorporated by reference or provided in this prospectus. We have not authorized anyone else to provide you with different information. You should not assume that the information in this prospectus is accurate as of any date other than the date of this prospectus or the date of the documents incorporated by reference in this prospectus.

We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus.

Requests for such documents should be directed to:

KaloBios Pharmaceuticals, Inc.

260 East Grand Avenue

South San Francisco, CA 94080

(650) 243-3100

You may also access the documents incorporated by reference in this prospectus through our website at www.kalobios.com. Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated inby reference into this prospectusprospectus.

You may request a free copy of these filings (other than an exhibit to a filing unless that exhibit is specifically incorporated by reference into that filing) by writing or the registration statement of which it forms a part.

telephoning us as follows:

$50,000,000Humanigen, Inc.
Attention: Corporate Secretary
830 Morris Turnpike, 4^th Floor

Short Hills, New Jersey 07078

(973) 200-3010

COMMON STOCK

PROSPECTUS

The date of this prospectus is                 , 2013.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Information Not Required in Prospectus

Item 14. Other Expenses of Issuance and Distribution

The following table sets forthis a statement of the estimated costs and expenses (other than the actual registration fee), other than underwriting discounts and commissions, payable(all of which are estimated) to be incurred by the registrantus in connection with the saleissuance and distribution of the securities being registered.registered under this registration statement:

Item 15. Indemnification of Directors and Officers

Section 145(a)102(b)(7) of the Delaware General Corporation Law, or the DGCL, provides that a Delaware corporation, in its certificate of incorporation, may limit the personal liability of a director to the corporation or its stockholders for monetary damages for breach of fiduciary duties as a director, except for liability for any:

Section 145(a) of the DGCL provides, in general, that a Delaware corporation may indemnify any person who was or is a party, or is threatened to be made a party, to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the factbecause that such person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or enterprise, againstother enterprise. The indemnity may include expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by suchthe person in connection with such action, suit or proceeding if he or sheso long as the person acted in good faith and in a manner he or she reasonably believed to bewas in or not opposed to the corporation’s best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Section 145(b) of the Delaware General Corporation LawDGCL provides, in general, that a Delaware corporation may indemnify any person who was or is a party, or is threatened to be made a party, to any threatened, pending or completed action or suit by or in the right of the corporation to procureobtain a judgment in its favor by reasonbecause the person is or was a director, officer, employee or agent of the fact that such person acted in anycorporation, or is or was serving at the request of the capacities set forth above, againstcorporation as a director, officer, employee or agent of another corporation or other enterprise. The indemnity may include expenses (including attorneys’ fees) actually and reasonably incurred by suchthe person in connection with the defense or settlement of such action, so long as the person acted in good faith and in a manner the person reasonably believed was in or suit if he or she acted under similar standards,not opposed to the corporation’s best interests, except that no indemnification mayshall be made in respect of any claim, issue or matter as to which suchpermitted without judicial approval if a court has determined that the person shall have been adjudgedis to be liable to the corporation unless and onlywith respect to the extent that the court in which such action or suit was brought shall determine that, despite the adjudication of liability but in view of all the circumstancesclaim. Section 145(c) of the case, such person is fairly and reasonably entitled to be indemnified for such expenses which the court shall deem proper.

Section 145 of the Delaware General Corporation LawDGCL further provides that: (i) to the extent that, if a formerpresent or presentformer director or officer of a corporation has been successful in the defense of any action suit or proceeding referred to in subsections (a) and (b)above, the corporation must indemnify such officer or indirector against the defense of any claim, issue or matter therein, such person shall be indemnified against expenses (including attorneys’ fees) he or she actually and reasonably incurred by him or her in connection therewith; (ii) indemnification provided for by with such action.

Section 145 shall not be deemed exclusive145(g) of any other rights to which the indemnified party may be entitled; and (iii) theDGCL provides, in general, that a corporation may purchase and maintain insurance on behalf of any presentperson who is or formerwas a director, officer, employee or agent of the corporation, or any person

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whois or was serving at the request of the corporation was serving in such capacity foras a director, officer, employee or agent of another entitycorporation or other enterprise against any liability asserted against such person and incurred by him or hersuch person, in any such capacity, or arising out of his or her status as such, whether or not the corporation could indemnify the person against such liability under Section 145 of the DGCL.

Our Charter eliminates the personal liability of our directors to the Company and our stockholders for monetary damages for breach of fiduciary duty as a director, with certain limited exceptions set forth therein. Our Second Amended and Restated Bylaws provide for the indemnification of our directors and officers to the fullest extent permitted by the DGCL.

We maintain an insurance policy that covers certain liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers.

Certain of our non-employee directors may, through their relationships with their employers, also be insured and/or indemnified against certain liabilities incurred in their capacity as members of our board of directors.

The foregoing descriptions are only general summaries.

Item 16. Exhibits

Item 17. Undertakings

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933 (the “Securities Act”);

(ii) to reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would havenot exceed that which was registered) and any deviation from the powerlow or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to indemnify himRule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement; and

(iii) to include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or herany material change to such information in the Registration Statement;

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) that are incorporated by reference into the Registration Statement or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the Registration Statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities under Section 145.

In accordance with our amended and restated certificate(other than the payment by the registrant of incorporation and our amended and restated bylaws, we have indemnification obligations to our officers and directors for specified eventsexpenses incurred or occurrences, subject to some limits, while they are serving at our request in such capacities. We have also entered into indemnification agreements with our directors, executive officers, and key employees and intend to enter into indemnification agreements with any new directors and executive officerspaid by a director, officer or controlling person of the registrant in the future.

We have purchased and intend to maintain insurance on behalfsuccessful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person whoin connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is or was a director or officer against any loss arising from any claim asserted against him or herpublic policy as expressed in the Securities Act and incurredwill be governed by him or her in anythe final adjudication of such capacity, subject to certain exclusions.

See also the undertakings set out in response to Item 17 herein.issue.

A list of exhibits filed herewith is contained in the exhibit index that immediately precedes such exhibits and is incorporated herein by reference.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrantregistrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement on Form S-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of South San Francisco,Short Hills, State of California,New Jersey, on this 3the 1^rdst day of September, 2013.March, 2022.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that eachEach person whose signature appears below hereby constitutes and appoints David W. PritchardCameron Durrant and Jeffrey H. Cooper,Timothy Morris, and each of them, acting individually, as his or her true and lawful attorneys-in-fact and agents, with full power of each to act alone, with full powers of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including, without limitation, post-effective amendments) to this registration statement, on Form S-3and any registration statement relating to the offering covered by this registration statement and filed pursuant to Rule 462(b) under the Securities Act of 1933, and to file the same, with all exhibits thereto, and allother documents in connection therewith, including a Registration Statementwith the Securities Exchange Commission, under Rule 462(b) of the Securities Act with the Securities and Exchange Commission,of 1933, granting unto said attorneys-in-fact and agents, with full powerand each of each to act alone,them, full power and authority to do and perform each and every act and thing requisite and necessary to be done, in connection therewith, as fully forto all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that each of said attorneys-in-fact and agents or histheir substitute or their substitutes may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this reportregistration statement has been signed below by the following persons on behalf of the registrant and in the capacities andindicated on the dates hereafter indicated.

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EXHIBIT INDEX