As filed with the Securities and Exchange Commission on October 15, 2019December 22, 2023

RegistrationNo. 333-          

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington,WASHINGTON, D.C. 20549

FORMS-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Gritstone Oncology, Inc.GRITSTONE BIO, INC.

(Exact name of Registrantregistrant as specified in its charter)

58585959 Horton Street, Suite 210300

Emeryville, California 94608

(510)871-6100

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

Andrew Allen, M.D., Ph.D.

President and Chief Executive Officer

Gritstone Oncology,bio, Inc.

58585959 Horton Street, Suite 210300

Emeryville, California 94608

(510)871-6100

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

Copies to:

Effie Toshav, Esq.

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.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:  ☒

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:  ☐

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

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

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D.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.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act. (Check one):

If 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 information in this prospectus is not complete and may be changed. These securitiesWe may not be soldsell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell nor doesthese securities, and it seekis not soliciting an offer to buy these securities, in any jurisdictionstate where the offer or sale is not permitted.

Subject to Completion, dated October 15, 2019.SUBJECT TO COMPLETION, DATED DECEMBER 22, 2023

PROSPECTUS

$250,000,000

Gritstone Oncology,bio, Inc.

Common Stock,

Preferred Stock,

Debt Securities,

Warrants,

Subscription Rights and Units

We

From time to time, we may offer and sell up to $250,000,000$250.0 million aggregate dollar amount of shares of our common stock or preferred stock, debt securities, warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debt securities and/or units consisting of some or all of these securities, in the aggregate of the securities identified above from time to timeany combination, together or separately, in one or more offerings. This prospectus provides you with a general description ofofferings, in amounts, at prices and on the securities.

Each time we offer and sell securities,terms that we will provide a supplement to this prospectus that contains specific information aboutdetermine at the time of the offering and the amounts, priceswhich will be set forth in a prospectus supplement and terms of the securities.any related free writing prospectus. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus with respectprospectus. The total amount of these securities will have an initial aggregate offering price of up to that offering. $250.0 million.

You should carefully read this prospectus, and the applicable prospectus supplement before you invest in any of our securities.

We may offer and sell the securities describedinformation incorporated, or deemed to be incorporated, by reference in this prospectus, and any applicable prospectus supplement and related free writing prospectus carefully before you invest.

Our common stock is traded on The Nasdaq Global Select Market under the symbol “GRTS.” On December 21, 2023 the last reported sales price for our common stock was $1.64 per share. None of the other securities we may offer are currently traded on any securities exchange. The applicable prospectus supplement and any related free writing prospectus will contain information, where applicable, as to any other listing on The Nasdaq Global Select Market or any securities market or exchange of the securities covered by the prospectus supplement and any related free writing prospectus.

An investment in our securities involves a high degree of risk. You should carefully consider the information under the heading “Risk Factors ” beginning on page 4 of this prospectus before investing in our securities.

Common stock, preferred stock, debt securities, warrants, subscription rights and/or units may be sold by us to or through oneunderwriters or more underwriters, dealers, and agents, or directly to purchasers or through a combinationagents designated from time to time. For additional information on the methods of these methods.sale, you should refer to the section entitled “Plan of Distribution” in this prospectus. If any underwriters, dealers or agents are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of the securities, their namessuch underwriters or agents and any applicable purchase price, fee, commissionfees, discounts or discount arrangement between or among themcommissions, details regarding over-allotment options, if any, and the net proceeds to us will be set forth orin a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be calculable from the information set forth in the applicablea prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of 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.

INVESTING IN OUR SECURITIES INVOLVES RISKS. SEE THE “RISK FACTORS” ON PAGE 5 OF THIS PROSPECTUS AND ANY SIMILAR SECTION CONTAINED IN THE APPLICABLE PROSPECTUS SUPPLEMENT CONCERNING FACTORS YOU SHOULD CONSIDER BEFORE INVESTING IN OUR SECURITIES.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GRTS.” On October 11, 2019, the last reported sale price of our common stock on the Nasdaq Global Select Market was $8.61 per share.

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

The date of this prospectus is                , 2019.2023

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission or the SEC,(“SEC”), using a “shelf” registration process. By using aUnder this shelf registration statement, we may sell securitiesprocess, from time to time, andwe may sell any combination of the securities described in this prospectus in one or more offerings, up to a total dollar amount of $250,000,000 as described in this prospectus.$250.0 million. Each time that we offer and sellour securities under this prospectus, we will provide a prospectus supplement to this prospectus that containswill contain more specific information about the securities being offered and sold and the specific terms of thatthe offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement or free writing prospectus may also add, update or change in a prospectus supplement any of the information contained in this prospectus with respect to that offering. Ifor in documents we have incorporated by reference into this prospectus. To the extent there is any inconsistencya conflict between the information contained in this prospectus and the applicable prospectus supplement, or free writing prospectus, you should rely on the information in the prospectus supplementsupplement; provided that, if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in this prospectus or free writingany prospectus as applicable. Before purchasing any securities, yousupplement—the statement in the document having the later date modifies or supersedes the earlier statement. This prospectus, together with the applicable prospectus supplements and the documents incorporated by reference into this prospectus, includes all material information relating to this offering. You should carefully read both this prospectus and the applicable prospectus supplement, (and any applicable free writing prospectuses), together with the additional information described under the headingheadings “Incorporation of Information by Reference” and “Where You Can Find More Information; Incorporation by Reference.”Information” before buying any of our securities in this offering.

WeNeither we, nor any agent, underwriter or dealer have not authorized anyone to providegive you with any information or to make any representationsrepresentation other than thosethe information and representations contained in or incorporated by reference into this prospectus or any applicable prospectus supplementsupplement. We and any agent, underwriter or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. Wedealer take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We willYou may not make an offer to sell these securities inimply from the delivery of this prospectus and any jurisdiction whereapplicable prospectus supplement, nor from a sale made under this prospectus and any applicable prospectus supplement, that our affairs are unchanged since the offerdate of this prospectus and any applicable prospectus supplement or sale is not permitted. You should assume that the information appearing in this prospectus and the applicable prospectus supplement to this prospectus is accurate only as of the date on its respective cover, that the information appearingcontained in any applicable free writing prospectus is accurate only as of the date of that free writing prospectus, and that any informationdocument incorporated by reference is accurate only as of any date other than the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, resultsregardless of operationsthe time of delivery of this prospectus and prospects may have changed since those dates. This prospectus incorporates by reference, and any applicable prospectus supplement or free writingany sale of a security. This prospectus and any applicable prospectus supplement may only be used where it is legal to sell the securities.

THIS PROSPECTUS MAY NOT BE USED TO OFFER AND SELL SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

In this prospectus, unless the context otherwise requires, the terms “GRTS,” the “Company,” “we,” “us,” and “our” refer to Gritstone bio, Inc., a Delaware corporation, and its subsidiaries unless otherwise specified. This prospectus, any accompanying prospectus supplement and the information incorporated by reference herein and therein may contain additional trade names, trademarks and incorporate by reference, market data and industry statistics and forecasts thatservice marks of other companies, which are based on independent industry publications and other publicly available information. Although we believe these sources are reliable, wethe property of their respective owners. We do not guarantee the accuracyintend our use or completenessdisplay of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, these other companies.

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RISK FACTORS

InvestmentAn investment in anyour securities offered pursuantinvolves a high degree of risk. The prospectus supplement applicable to this prospectus andeach offering of 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 Factors” in the applicable prospectus supplement, involves risks. You should carefully considertogether with all of the risk factors included in our most recent Annual Report onForm 10-K, our most recent Quarterly Report on Form10-Q and any subsequent Quarterly Reports onForm 10-Q or Current Reports on Form8-K we file after the date of this prospectus, and all 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 Part I, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K and under Part II, Item 1A, “Risk Factors,” in our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2023, June 30, 2023 and September 30, 2023, which are incorporated herein by reference, and may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future and which are incorporated herein by reference. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and documents incorporated herein by reference contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward-looking statements by terms such as “believe,” “may,” “will,” “potentially,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “plan,” “expect,” “predict,” “potential” and similar expressions that convey uncertainty of future events or outcomes, although not all forward-looking statements contain these words. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described in Part I, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K and under Part II, Item 1A, “Risk Factors,” in our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2023, June 30, 2023 and September 30, 2023 as well as those discussed in this prospectus, the documents incorporated by reference into this prospectus and any free writing prospectus. Moreover, we operate in a competitive and rapidly changing environment, and new risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed in this prospectus may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements. The forward-looking statements in this prospectus include, among other things, statements about:

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The forward-looking statements made in this prospectus relate only to events or information as updatedof the date on which the statements are made in this prospectus. You should not rely upon forward-looking statements as predictions of future events. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee that the future results, levels of activity, performance or events and circumstances reflected in the forward-looking statements will be achieved or occur. We undertake no obligation to update publicly any forward-looking statements for any reason after the date of this prospectus to conform these statements to actual results or to changes in our expectations, except as required by our subsequent filingslaw. We intend the forward-looking statements contained in this prospectus to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the securities offered hereby. This prospectus, which constitutes a part of the registration statement, does not contain all of the information set forth in the registration statement, the exhibits filed therewith or the documents incorporated by reference therein. For further information about us and the securities offered hereby, reference is made to the registration statement, the exhibits filed therewith and the documents incorporated by reference therein. Statements contained in this prospectus regarding the contents of any contract or any other document that is filed as an exhibit to the registration statement are not necessarily complete, and in each instance, we refer you to the copy of such contract or other document filed as an exhibit to the registration statement.

We are subject to the informational requirements of the Exchange Act and the risk factorsare required to file annual, quarterly and other reports, proxy statements and other information with the SEC. The SEC maintains an Internet site (http://www.sec.gov) that contains reports, proxy and information statements, and various other information about us. You may also inspect the documents described herein at our principal executive offices, 5959 Horton Street, Suite 300, Emeryville, California 94608, during normal business hours.

Information about us is also available at our website at www.gritstonebio.com. However, the information on our website is not a part of this prospectus and is not incorporated by reference into this prospectus.

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INCORPORATION OF INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with the SEC, which means that we can disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information we file later with the SEC will automatically update and supersede this information. A Current Report (or portion thereof) furnished, but not filed, on Form 8-K shall not be incorporated by reference into this prospectus. We incorporate by reference the documents listed below and any future filings we make with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Exchange Act prior to the termination of any offering of securities made by this prospectus:

We will furnish without charge to you, on written or oral request, a copy of any or all of such documents that has been incorporated herein by reference (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into the documents that this prospectus incorporates). Written or oral requests for copies should be directed to Gritstone bio, Inc., Attn: Investor Relations, 5959 Horton Street, Suite 300, Emeryville, California 94608, and our telephone number is (510) 871-6100. See the section of this prospectus entitled “Where You Can Find More Information” for information concerning how to obtain copies of materials that we file with the SEC.

Any statement contained in this prospectus, or in a document, all or a portion of which is incorporated by reference, shall be modified or superseded for purposes of this prospectus to the applicableextent that a statement contained in this prospectus, any prospectus supplement andor any applicable free writing prospectus before acquiring any ofdocument incorporated by reference modifies or supersedes such securities. The occurrence of any of these risks might cause you to lose allstatement. Any such statement so modified or superseded shall not, except as so modified or superseded, constitute a part of your investment in the offered securities.this prospectus.

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USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds to us from the sale of our securities under this prospectus. Unless otherwise provided in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities asunder this prospectus for general corporate purposes, which may include funding research, clinical development, process development and manufacturing of our product candidates, increasing our working capital, reducing indebtedness, acquisitions or investments in businesses, products or technologies that are complementary to our own and capital expenditures. We will set forth in the applicable prospectus supplement.supplement our intended use for the net proceeds received from the sale of any securities. Pending the application of the net proceeds, we intend to invest the net proceeds in short-term or long-term, investment-grade, interest-bearing securities.

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PLAN OF DISTRIBUTION

We may sell the securities covered by this prospectus to one or more underwriters for public offering and sale by them, and may also sell the securities to investors directly or through agents. We will name any underwriter or agent involved in the offer and sale of securities in the applicable prospectus supplement. We have reserved the right to sell or exchange securities directly to investors on our own behalf in jurisdictions where we are authorized to do so. We may distribute the securities from time to time in one or more transactions:

We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time. We will name in a prospectus supplement any agent involved in the offer or sale of our securities. Unless otherwise indicated in a prospectus supplement, an agent will be acting on a best efforts basis, and a dealer will purchase securities as a principal for resale at varying prices to be determined by the dealer.

If we utilize an underwriter in the sale of the securities being offered by this prospectus, we will execute an underwriting agreement with the underwriter at the time of sale and we will provide the name of any underwriter in the prospectus supplement that the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agent.

We will provide in the applicable prospectus supplement any compensation we pay to underwriters, dealers, or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. In compliance with the guidelines of the Financial Industry Regulatory Authority, Inc. (“FINRA”), the aggregate maximum discount, commission or agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer shall be fair and reasonable. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, and to reimburse them for certain expenses. We may grant underwriters who participate in the distribution of our securities under this prospectus an option to purchase additional securities in connection with the distribution.

The securities we offer under this prospectus may or may not be listed through The Nasdaq Global Select Market or any other securities exchange. To facilitate the offering of securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such short positions by making purchases in the open market or by exercising their option to purchase additional securities. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a

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level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and they may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in these sale transactions will be an underwriter and will be identified in the applicable prospectus supplement. In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus. The financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

We will file a prospectus supplement to describe the terms of any offering of our securities covered by this prospectus. The prospectus supplement will disclose:

We will bear all or substantially all of the costs, expenses and fees in connection with the registration of our securities under this prospectus. The underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise or the securities are sold by us to an underwriter in a firm commitment underwritten offering. The applicable 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 prior to 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.

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DESCRIPTION OF CAPITAL STOCK

General

The following summary describesdescription summarizes the most important terms of our capital stock and the material provisions of our amended and restated certificate of incorporation, our amended and restated bylaws, the amended and restated investors’ rights agreement to which we and certain of our stockholders are parties and of the Delaware General Corporation Law.stock. Because the followingit is only a summary, it does not contain all of the information that may be important to you. For a complete description, you should refer to our amended and restated certificate of incorporation amended and restated bylaws, and amended and restated investor rights agreement, copies of which are incorporated by referenceincluded as exhibits to the registration statement of which this prospectus isforms a part.part, and to the applicable provisions of Delaware law.

GeneralCommon Stock

OurAs of September 30, 2023, our authorized capital stock consists of 300,000,000 shares of common stock, $0.0001 par value per share, and 10,000,000 shares of preferred stock, $0.0001 par value per share. As of JuneSeptember 30, 2019,2023, there were outstanding:

The actual number of stockholders is greater than the number of record holders and includes stockholders who are beneficial owners but whose shares are held in street name by brokers and other nominees. This number of holders of record also does not include stockholders whose shares may be held in trust by other entities.

Our common stock, $0.0001 par value per share, was registered under Section 12 of the Securities Exchange Act of 1934, as amended, or the Exchange Act, and listed on the Nasdaq Global Select Market under the trading symbol “GRTS.”

The following description of our capital stock and provisions of our amended and restated certificate of incorporation and amended and restated bylaws are summaries of material terms and provisions and are qualified by reference to our amended and restated certificate of incorporation and amended and restated bylaws, copies of which have been filed with the SEC and are incorporated by reference as exhibits to the registration statement of which this prospectus is a part.

Common StockDividend Rights

Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our common stock are entitled to receive dividends, if any, as may be declared from time to time by our board of directors out of legally available funds.

Voting Rights

Each holder of our common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Our stockholders do not have cumulative voting rights in the election of directors. Accordingly, holders of a majority of the voting shares are able to elect all of the directors. In addition, the affirmative vote of holders of66-2/3% of the voting power of all of the then outstanding voting stock is required to take certain actions, including amending certain provisions of our amended and restated certificate of incorporation, such as the provisions relating to amending our amended and restated bylaws, the classified board and director liability.

Dividends

Subject to preferences that may be applicable to any then outstanding convertible preferred stock, holders of our common stock are entitled to receive dividends, if any, as may be declared from time to time by our board of directors out of legally available funds.

Liquidation

In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of convertible preferred stock.

Liquidation

In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of preferred stock.

Fully Paid and Nonassessable

All outstanding shares of common stock are fully paid and non-assessable.

Undesignated Preferred Stock

OurUnder our certificate of incorporation, our board of directors has the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock, $0.0001 par value per share, in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting, or the designation of, such series, any or all of which may be greater than the rights of common stock. The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change in control of our company or other corporate action. As of JuneSeptember 30, 2019,2023, no shares of convertible preferred stock arewere outstanding.

Options

As of JuneSeptember 30, 2019,2023, we had outstanding options to purchase 3,038,6987,265,543 shares of our common stock, with a per share weighted-average exercise price of $7.55, under our 2015 Equity Incentive Plan and 2018 Equity Incentive Plan.$7.55.

Registration Rights

Under our amended and restated investors’ rights agreement, based on the number of shares outstanding as of June 30, 2019, the holders of approximately 8.8 million shares of common stock, or their transferees, have the right to require us to register their shares under the Securities Act so that those shares may be publicly resold, and the holders of approximately 8.8 million shares of common stock, or their transferees, have the right to include their shares in any registration statement we file, in each case as described below.

Demand Registration Rights

Based on the number of shares outstanding as of June 30, 2019, the holders of approximately 8.8 million shares of our common stock, or their transferees, are entitled to certain demand registration rights. The holders of at least 30% of these shares (or a lesser percent if the anticipated aggregate offering price to the public net of certain expenses would exceed $10 million) can request that we register all or a portion of their shares. Additionally, we are not required to effect a demand registration during the period beginning 120 days prior to the filing and ending 180 days following the effectiveness of a company-initiated registration statement relating to a public offering of our securities.

Piggyback Registration Rights

Based on the number of shares outstanding as of June 30, 2019, in the event that we determine to register any of our securities under the Securities Act (subject to certain exceptions), either for our own account or for the account of other security holders, the holders of approximately 8.8 million shares of our common stock, or their transferees, are entitled to certain “piggyback” registration rights allowing the holders to include their shares in such registration, subject to certain marketing and other limitations. As a result, whenever we propose to file a registration statement under the Securities Act, other than with respect to a registration related to employee

or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation’s voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors, such as discouraging takeover attempts that might result in a premium over the market price of our common stock.

Undesignated Preferred Stock

The ability to authorize undesignated preferred stock makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to change control of us. These and other provisions may have the effect of deterring hostile takeovers or delaying changes in control or management of our company.

Special Stockholder Meetings

Our amended and restated bylaws provide that a special meeting of stockholders may be called by our board of directors, or by our President (in the absence of a Chief Executive Officer) or Chief Executive Officer.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our amended and restated 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 the board of directors or a committee of the board of directors.

Elimination of Stockholder Action by Written Consent

Our amended and restated certificate of incorporation and our amended and restated bylaws eliminate the right of stockholders to act by written consent without a meeting.

Classified Board; Election and Removal of Directors; Filling Vacancies

Our board of directors is divided into three classes. The directors in each class will serve for a three-year term, one class being elected each year by our stockholders, with staggered three-year terms. Only one class of directors will be elected at each annual meeting of our stockholders, with the other classes continuing for the remainder of their respective three-year terms. Because our stockholders do not have cumulative voting rights, our stockholders holding a majority of the shares of common stock outstanding will be able to elect all of our directors. Our amended and restated certificate of incorporation provides for the removal of any of our directors only for cause and requires a stockholder vote by the holders of at least a66-2/3% of the voting power of the then outstanding voting stock. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of the board, may only be filled by a resolution of the board of directors unless the board of directors determines that such vacancies shall be filled by the stockholders. This system of electing and removing directors and filling vacancies may tend to discourage a third party from making a tender offer or otherwise attempting to obtain control of us, because it generally makes it more difficult for stockholders to replace a majority of the directors.

Choice of Forum

Our amended and restated certificate of incorporation and our amended and restated bylaws provide that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware is

of fiduciary duty; any action asserting a claim against us arising pursuant to the Delaware General Corporation Law, our amended and restated certificate of incorporation or our amended and restated bylaws; or any action asserting a claim against us that is governed by the internal affairs doctrine. The exclusive forum provision will not apply to suits brought to enforce any liability or duty created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction. In addition, our amended and restated certificate of incorporation provides that the U.S. federal district courts are the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act. AlthoughOur exclusive forum provision will not relieve us of our amendedduties to comply with the federal securities laws and restated certificatethe rules and regulations thereunder, and our stockholders will not be deemed to have waived our compliance with these laws, rules and regulations.

The enforceability of incorporation and amended and restated bylaws contain thesimilar federal court choice of forum provisions described above,in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that a court could find this type of provision to be inapplicable or unenforceable. If a court were to find either of the choice of forum provisions contained in our amended and restated certificate of incorporation or amended and restated bylaws to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions.

The choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with the company or its directors, officers or other employees, which may discourage such lawsuits against the company and its directors, officers and other employees and result in increased costs for investors to bring a provision is inapplicable for a particular claim or action or that such provision is unenforceable.claim.

Amendment of Charter Provisionsthe Certificate of Incorporation and Bylaws

The amendment of any of the above provisions, except for the provision making it possible for our board of directors to issue undesignated preferred stock, would require approval by a stockholder vote by the holders of at least a66-2/3% of the voting power of the then outstanding voting stock. The provisions of the Delaware General Corporation Law, our amended and restated certificate of incorporation and our amended and restated bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

Limitations of Liability and Indemnification Matters

Our amended and restated certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law. Consequently, our directors willare not be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for:

Each of our amended and restated certificate of incorporation and amended and restated bylaws provide that we are required to indemnify our directors and officers, in each case to the fullest extent permitted by Delaware law. Our amended and restated bylaws also obligateobligates us to advance expenses incurred by a director or officer in

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advance of the final disposition of any action or proceeding, and permit us to secure insurance on behalf of any officer, director, employee or other agent for any liability arising out of his or her actions in that capacity regardless of whether we would otherwise be permitted to indemnify him or her under Delaware law. We have entered and expect to continue to enter into agreements to indemnify our directors, executive officers and other employees as determined by our board of directors. With specified exceptions, these agreements provide for indemnification for related expenses including, among other things, attorneys’ fees, judgments, fines and settlement amounts incurred by any of these individuals in any action or proceeding. We believe that these bylaw provisions and indemnification agreements are necessary to attract and retain qualified persons as directors and officers. We also maintain directors’ and officers’ liability insurance.

The limitation of liability and indemnification provisions in our amended and restated certificate of incorporation and amended and restated bylaws may discourage stockholders from bringing a lawsuit against our directors and

DESCRIPTION OF DEBT SECURITIES

The following description, together withGeneral

We may issue the additional information we includedebt securities offered by this prospectus and any accompanying prospectus supplement under an indenture to be entered into between us and the trustee identified in anythe applicable prospectus supplement or free writing prospectus, summarizes certain generalsupplement. The terms and provisions of the debt securities that we may offer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicateinclude those stated in the supplement to what extent the general termsindenture and provisions described in this prospectus apply to a particular series of debt securities.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and may be issued in one or more series.

The debt securities will be issued under an indenture between us and a third party to be identified therein, as trustee. We have summarized select portionsthose made part of the indenture below. The summary is not complete. Theby reference to the Trust Indenture Act of 1939 (“Trust Indenture Act”), as in effect on the date of the indenture. We have filed a copy of the form of the indenture has been filed as an exhibit to the registration statement in which this prospectus is included. The indenture will be subject to and you should readgoverned by the indenture for provisions thatterms of the Trust Indenture Act. We may offer under this prospectus up to an aggregate principal amount of $250.0 million in debt securities, or if debt securities are issued at a discount, or in a foreign currency, foreign currency units or composite currency, the principal amount as may be importantsold for an aggregate public offering price of up to you. In the summary below, we have included references to the section numbers of the indenture so that you can easily locate these provisions. Capitalized terms used in the summary and not defined herein have the meanings$250.0 million. Unless otherwise specified in the indenture.

As used in this section only, “Gritstone,” “we,” “our” or “us” refer to Gritstone Oncology, Inc., unless expressly stated orapplicable prospectus supplement, the context otherwise requires.

General

The terms of each series of debt securities will be established by or pursuant to a resolutionrepresent our direct, unsecured obligations and will rank equally with all of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. (Section 2.2) The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet).other unsecured indebtedness.

We canmay issue an unlimited amount ofthe debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. (Section 2.1) We will set forthdescribe the particular terms of each series of debt securities in a prospectus supplement (including any pricing supplement or term sheet) relating to anythat series, which we will file with the SEC. The prospectus supplement relating to the particular series of debt securities being offered will specify the particular amounts, prices and terms of those debt securities. These terms may include:

Registered Global Securities

If we decide to issue debt securities in the form of one or more global securities, registered inthen we will register the name of The Depository Trust Company, or the Depositary, or a nominee of the Depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth under the heading “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. (Section 2.4) No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange. (Section 2.7)

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the Depositary, and registered in the name of the Depositarydepositary for the global securities or athe nominee of the Depositary. Please see “Global Securities.”

Covenants

Wedepositary, and the global securities will set forthbe delivered by the trustee to the depositary for credit to the accounts of the holders of beneficial interests in the applicabledebt securities.

The prospectus supplement will describe the specific terms of the depositary arrangement for debt securities of a series that are issued in global form. None of us, the trustee, any restrictive covenants applicablepayment agent or the security registrar will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any issue of debt securities. (Article IV)records relating to these beneficial ownership interests.

No Protection in the Event of a Change of Control

The indenture does not have any covenants or other provisions providing for a put or increased interest or otherwise that would afford holders of our debt securities additional protection in the event of a recapitalization transaction, a change of control or a highly leveraged transaction. If we offer any covenants or provisions of this type with respect to any debt securities covered by this prospectus, we will describe them in the applicable prospectus supplement.

Covenants

Unless we state otherwise indicated in this prospectus or the applicable prospectus supplement, our debt securities will not have the benefit of any covenants that limit or restrict our business or operations, the pledging of our assets or the incurrence by us of indebtedness. We will describe in the applicable prospectus supplement the debt securities will not contain any provisions which may afford holders of the debt securities protectionmaterial covenants in the event we have a change in control or in the eventrespect of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holdersseries of debt securities.

Merger, Consolidation Merger andor Sale of Assets

We mayThe form of indenture provides that we will not consolidate with or merge with or into any other person or convey, transfer, sell or lease all or substantially all of our properties and assets substantially as an entirety to any person, (a “successor person”) unless:

Events of Default

“EventUnless otherwise specified in the applicable prospectus supplement, the following events will be events of Default” meansdefault under the indenture with respect to any series of debt securities of any of the following:series:

No EventIf an event of Default with respect to a particular seriesdefault (other than an event of debt securities (except as todefault resulting from certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other series of debt securities. (Section 6.1) The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

We will provide the trustee written notice of any Default or Event of Default within 30 days of becoming aware of the occurrence of such Default or Event of Default, which notice will describe in reasonable detail the status of such Default or Event of Default and what action we are taking or propose to take in respect thereof. (Section 6.1)

If an Event of Default with respect to debt securities of any series at the time outstanding occurs, and is continuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of thatany series may by a notice in writing to us (andaccelerate the maturity of the debt securities. If this happens, the entire principal amount, plus the premium, if any, of all the outstanding debt securities of the affected series plus accrued interest to the trustee if givendate of acceleration will be immediately due and payable. At any time after the acceleration, but before a judgment or decree based on such acceleration is obtained by the holders), declaretrustee, the holders of a majority in aggregate principal amount of outstanding debt securities of such series may rescind and annul such acceleration if:

In addition, if the acceleration occurs at any time when we have outstanding indebtedness that is senior to be due and payable immediately the principal of (or, if the debt securities, of that series are discount securities, that portionthe payment of the principal amount asof outstanding debt securities may be specifiedsubordinated in right of payment to the prior payment of any amounts due under the senior indebtedness, in which case the holders of debt securities will be entitled to payment under the terms prescribed in the termsinstruments evidencing the senior indebtedness and the indenture.

If an event of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an Event of Defaultdefault resulting from certain events of bankruptcy, insolvency or reorganization occurs, the principal, (or such specified amount)premium and interest amount with respect to all of and accrued and unpaid interest, if any, on all outstandingthe debt securities of any series will become and be immediately due and payable immediately without any declaration or other act on the part of the trustee or any holderthe holders of outstanding debt securities. At any time after a declaration of acceleration with respect tothe debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, thethat series.

The holders of a majority in principal amount of the outstanding debt securities of thata series may rescind and annulwill have the acceleration if all Eventsright to waive any existing default or compliance with any provision of Default, other than thenon-payment of accelerated principal and interest, if any, with respect to indenture or the debt securities of that series have been cured or waived as provided in the indenture. (Section 6.2) We refer you to the prospectus

These limitations do not, however, apply to institute the proceeding within 60 days. (Section 6.7)

make any change to certain provisions of the indenture relating to, among other things, the right of holders of debt securities to receive payment of the principal of, premium and interest on those debt securities and to institute suit for the enforcement of any such payment and to waivers or amendments; or

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of shares of our debt securities, preferred stock, common stock, or preferred stock or of debt securities. Weany combination thereof. Warrants may issue warrantsbe issued independently or together with otherour debt securities, preferred stock or common stock and the warrants may be attached to or separate from any offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and the investorsa bank or atrust company, as warrant agent. The followingwarrant agent will act solely as our agent in connection with the warrants. 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 of materialcertain provisions of the warrants and warrant agreements are subject to, and qualified in their entirety by reference to, allis not complete. For the provisionsterms of the warrant agreement and warrant certificate applicable to a particular series of warrants. The terms of any warrants, offered under ayou should refer to the prospectus supplement may differ fromfor that series of warrants and the terms described below. We urge you to read the applicablewarrant agreement for that particular series.

Debt Warrants

The prospectus supplement and any related free writing prospectus, as well as the complete warrant agreements and warrant certificates that containrelating to a particular issue of warrants to purchase debt securities will describe the terms of the warrants.

The particular terms of any issue ofdebt warrants, will be described inincluding the prospectus supplement relating to the issue. Those terms may include:following:

Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations. Debt warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement. Prior to the exercise of their debt warrants, holders of debt warrants will not have any of the rights of holders of the debt securities purchasable upon exercise and will not be entitled to payment of principal or any premium, if any, or interest on the debt securities purchasable upon exercise.

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Equity Warrants

The prospectus supplement relating to a particular series of warrants to purchase our common stock or preferred stock will describe the terms of the warrants, including the following:

Holders of equity warrants will not be entitled:

Each warrant will entitle its holder

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DESCRIPTION OF SUBSCRIPTION RIGHTS

We may issue subscription rights to purchase our common stock, preferred stock or debt securities. These subscription rights may be offered independently or together with any other security offered hereby and may or may not be transferable by the principal amountstockholder receiving the subscription rights in such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

The prospectus supplement relating to any subscription rights we offer, if any, will, to the extent applicable, include specific terms relating to the offering, including some or all of the following:

The description in the applicable prospectus supplement holders of the warrants may exercise the warrants at any time upsubscription rights we offer will not necessarily be complete and will be qualified in its entirety by reference to the specified time onapplicable subscription rights certificate, which will be filed with the expiration date thatSEC if we set forth inoffer subscription rights. We urge you to read the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

DESCRIPTION OF UNITS

We may issue units consisting of any combination of the other types of securities offered under this prospectus in onesome or more series. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of the unit agent in the applicable prospectus supplement relating to a particular series of units.

The following description, together with the additional information included in any applicable prospectus supplement, summarizes the general features of the units that we may offer under this prospectus. You should read any prospectus supplement and any free writing prospectus that we may authorize to be provided to you related to the series of units being offered, as well as the complete unit agreements that contain the terms of the units. Specific unit agreements will contain additional important terms and provisions and we will file as an exhibit to the registration statement of which this prospectus is 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.

If we offer any units, certain terms of that series of units will be described in the applicable prospectus supplement, including, without limitation, the following, as applicable:

$75,000,000

Up to $250,000,000

Common Stock

We have entered into a sales agreement with Cowen and Company, LLC, or Cowen, relating to shares of our common stock offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the sales agreement, we may offer and sell shares of our common stock, $0.0001 par value per share, having an aggregate offering price of up to $75,000,000 from time to time through Cowen acting as our agent.Preferred Stock

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GRTS.” On October 11, 2019, the last reported sale price of our common stock on the Nasdaq Global Select Market was $8.61 per share.Debt Securities

Sales of our common stock, if any, under this prospectus supplement and the accompanying prospectus will be made in sales deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or the Securities Act. Cowen is not required to sell any specific amount of securities, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between Cowen and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.Warrants

The compensation to Cowen for sales of common stock pursuant to the sales agreement will be an amount equal to 3% of the gross proceeds of any shares of common stock sold under the sales agreement. In connection with the sale of the common stock on our behalf, Cowen will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cowen will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to Cowen with respect to certain liabilities, including liabilities under the Securities Act or the Exchange Act of 1934, as amended.Subscription Rights

Our business and an investment in our common stock involve significant risks. These risks are described under the caption “Risk Factors” beginning on pageS-7 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

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.

Cowen

The date of this prospectus is                , 2019

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.

The following is an estimate (other than the SEC registration fee and FINRA filing fee) of thetable sets forth estimated expenses that we may incur in connection with the issuance and distribution of the securities being registered hereby. All such expenses are to be paid byEach item listed is estimated, except for the registrant.SEC registration fee.

As permitted by the Delaware General Corporation Law, the registrant has entered into separate indemnification agreements with each of the registrant’s directors and certain of the registrant’s officers which require the registrant, among other things, to indemnify them against certain liabilities which may arise by reason of their status as directors, officers or certain other employees.

The registrant has obtained and intends to maintain insurance policies under which its directors and officers are insured, within the limits and subject to the limitations of those policies, against certain expenses in connection with the defense of, and certain liabilities which might be imposed as a result of, actions, suits or proceedings to which they are parties by reason of being or having been directors or officers. The coverage provided by these policies may apply whether or not the registrant would have the power to indemnify such person against such liability under the provisions of the Delaware General Corporation Law.

These indemnification provisions and the indemnification agreements entered into between the registrant and the registrant’s officers and directors may be sufficiently broad to permit indemnification of the registrant’s officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act.Act of 1933, as amended.

(a)Item 16.

Exhibits

The exhibits listed below are filed (except where otherwise indicated) as part of this Registration Statement.

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(2) That, for the purpose of determining any liability under the Securities Act of 1933, 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 of 1933 to any purchaser:

(A)(i) Each prospectus filed by the registrantRegistrant 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

(B)(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 sectionSection 10(a) of the Securities Act of 1933 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 registrantRegistrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

Thesecurities, the undersigned registrantRegistrant undertakes that in a primary offering of securities of the undersigned registrantRegistrant 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 registrantRegistrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

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

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

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

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(c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers, and controlling persons of the registrantRegistrant pursuant to the foregoing provisions, or otherwise, the registrantRegistrant has been advised that in the opinion of the SECSecurities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrantRegistrant of expenses incurred or paid by a director, officer, or controlling person of the registrantRegistrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person in connection with the securities being registered, the registrantRegistrant 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 against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

(d) The undersigned registrantIf and when applicable, the Registrant hereby further undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act (the “Act”) in accordance with the rules and regulations prescribed by the SECSecurities and Exchange Commission under sectionSection 305(b)(2) of the Trust Indenture Act.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrantRegistrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on FormS-3 and has duly caused this registration statementRegistration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Emeryville, State of California, on October 15, 2019.the 22nd day of December, 2023.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Andrew Allen M.D., Ph.D. and Jean-Marc Bellemin,Vassiliki “Celia” Economides, and each of them, acting individually, as his or her true and lawfulattorneys-in-fact, proxies and agents, each with full power of substitution, and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to file and sign any and all amendments including post-effective amendments and any registration statement for the same offering that is to be effective under Rule 462(b) of the Securities Act, to this registration statement (including post-effective amendments or any abbreviated registration statement and any amendments thereto filed pursuant to Rule 462(b) increasing the number of securities for which registration is sought), and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto saidattorneys-in-fact, proxies and agents 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 tofor all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that saidattorneys-in-fact, proxies and agents, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof. This power of attorney shall be governed by and construed with the laws of the State of Delaware and applicable federal securities laws.

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

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