As filed with the U.S. Securities and Exchange Commission on May 23, 2014April 4, 2019

RegistrationNo. 333-

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DCD.C. 20549

FORMS-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Registration Statement Under the Securities Act of 1933

PHARMATHENE,ALTIMMUNE, INC.

(Exact nameName of registrantRegistrant as specifiedSpecified in its charter)Charter)

One Park Place,Delaware

(State or Other Jurisdiction of Incorporation or Organization)

20-2726770

(I.R.S. Employer Identification No.)

910 Clopper Road, Suite 450201S

Annapolis,Gaithersburg, Maryland 21401

(410) 269-2600Telephone: (240)654-1450

(Address, including zip code,Including Zip Code, and telephone number, including area

 code,Telephone Number, Including Area Code, of Registrant’s principal executive offices)Principal Executive Offices)

Dr. Vipin K. Garg

President and Chief Executive Officer

PharmAthene,Altimmune, Inc.

One Park Place,910 Clopper Road, Suite 450201S

Annapolis,Gaithersburg, Maryland 21401

(410) 269-2600Telephone: (240)654-1450

(Name, address, including zip code, and telephone number,

including area code, of agent for service)

Copies to:

Jeffrey A. Baumel,Ori Solomon, Esq.

Anthony D. Foti, Esq.

Dentons USMorrison & Foerster LLP

1221 Avenue of the AmericasJohn Hancock Tower

New York, New York 10020200 Clarendon Street, Floor 20

Boston, MA 02116

(212) 768-6700Telephone: (617)648-4700

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 Formform are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ¨☐

If any of the securities being registered on this Formform 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.  x☒

If this Formform 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.  ¨☐

If this Formform 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 earlier effective registration statement for the same offering.  ¨☐

If this Formform 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.  ¨☐

If this Formform 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.  ¨

☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, or a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer” andfiler,” “smaller reporting company” and “emerging growth company” in Rule 12b–212b-2 of the Exchange Act. (Check one):Act:

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 Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

CALCULATION OF REGISTRATION FEE

(1)           There are being registered an indeterminate number of securities as shall have an aggregate offering price not to exceed $100,000,000.  The securities registered hereunder may be sold separately or with other securities registered hereunder.  The proposed maximum aggregate offering price per class of security will be determined from time to time by the registrant in connection with the issuance by the registrant of the securities registered under this registration statement and is not specified as to each class of security being registered under this registration statement pursuant to General Instruction II.D. of Form S-3 under the Securities Act of 1933, as amended (the “Securities Act”). The common stock to be issued pursuant to this registration statement may include the issuance of up to 2,899,991 shares of common stock issuable upon exercise of currently outstanding warrants.

(2)           The proposed maximum offering price has been estimated solely for the purpose of calculating the registration fee in accordance with Rule 457(o) under the Securities Act.

(3)           Subject to note 1 above, there is being registered hereunder an indeterminate number of shares of common and preferred stock of the registrant as may be sold from time to time by the registrant. Pursuant to Rule 416 under the Securities Act, the shares being registered hereunder include such indeterminate number of shares of common and preferred stock as may be issuable from time to time with respect to the shares being registered hereunder as a result of stock splits, stock dividends or similar transactions. Pursuant to Rule 457(i) under the Securities Act, the shares being registered hereunder include such indeterminate number of shares of common and preferred stock as may be issuable from time to time upon conversion, exercise or exchange of any preferred stock or warrants issued under this registration statement.

(4)           Subject to note 1 above, there is being registered hereunder an indeterminate number of warrants to purchase common stock or preferred stock of one or more series. Pursuant to Rule 457(i) under the Securities Act, the warrants being registered hereunder include such indeterminate number of warrants as may be issuable upon conversion or exchange of any preferred stock issued under this registration statement.

The Registrant hereby amends this Registration Statementregistration 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 Statementregistration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act, or until the Registration Statementregistration statement shall become effective on such date as the U.S. Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

This registration statement contains two prospectuses:

The base prospectus immediately follows this explanatory note. The sales agreement prospectus immediately follows the base prospectus. The additional $15,000,000 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 of securities that may be offered, issued and sold by us under the base prospectus.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the Registration Statementregistration statement filed with the U.S. 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 state or jurisdiction where the offer or sale is not permitted.

Subject to Completion, Dated May 23, 2014

dated April 4, 2019

PROSPECTUS

ALTIMMUNE, INC.

$100,000,000250,000,000

COMMON STOCK

PREFERRED STOCK

DEPOSITARY SHARES

DEBT SECURITIES

WARRANTS

STOCK PURCHASE CONTRACTS

STOCK PURCHASE UNITS

Common Stock

Preferred Stock

Warrants

___________________________

From time to time, weWe may offer and sell from time to time:

We may offer and sell these securities to or warrants or any combination of those securities, either individually or in units, inthrough one or more offerings. The aggregate public offering priceunderwriters, dealers and agents, or directly to purchasers, on a continuous or delayed basis. This prospectus describes some of the general terms that may apply to these securities offered by us pursuant to this prospectus will not exceed $100,000,000.

This prospectus provides you with aand the general description of the securities that we may offer. Each time we offer securities, we will provide a prospectus supplement that will contain more specific information about the terms of that offering, including the prices atmanner in which those securities will be sold. We may also add, update or change in the prospectus supplement any of the information contained in this prospectus.

The securities offered by us pursuant to this prospectusthey may be sold directly to investors, through agents, underwriters or dealers as designated from time to time, through a combination of these methods or in any other manner as described under the heading “Plan of Distribution” and in the corresponding section in the applicable prospectus supplement.  Each time we offer securities, the relevant prospectus supplement will provide theoffered. The specific terms of the plan of distribution for such offeringany securities to be offered, and the net proceeds that we expectspecific manner in which they may be offered, will be described in a supplement to receive from such offering.

this prospectus. You should read this prospectus and each applicable prospectus supplement carefully before you invest. This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

Our common stock is listed on the NYSE MKTNasdaq Global Market under the trading symbol “PIP.“ALT.” EachWe have not yet determined whether any of the other securities that may be offered by this prospectus supplement will indicate if the securities offered pursuant to thatand a prospectus supplement will be listed on any securities exchange.exchange, inter-dealer quotation system orover-the-counter market. Our principal executive offices are located at 910 Clopper Road, Suite 201S, Gaithersburg, Maryland 20878, and its telephone number is(240) 654-1450.

This prospectus may not be used to sell any of our securities unless accompanied by a prospectus supplement or a free writing prospectus.

Investing in our securities involves certain risks. You should carefully read both this prospectus and consider the applicable prospectus supplement, as well as any documents incorporated by referencerisk factors included in this prospectus and/orour periodic reports and other information that we file with the applicable prospectus supplement, before you make your investment decision.  See “Risk Factors” beginning on page 2 of this prospectusSecurities and contained in other documentsExchange Commission and that are incorporated by reference into this prospectus or any prospectus supplement before you invest in our securities. See “Risk Factors” on page 3 of this prospectus.prospectus and any risk factors contained in any applicable prospectus supplement.

Neither the U.S. Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of these securities or determined ifpassed upon the adequacy or accuracy of this prospectus is truthful or complete.prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is                 , 2014. 2019.

ABOUT THIS PROSPECTUS

You should rely only onUnless otherwise indicated or the information contained or incorporated by referencecontext otherwise requires, all references in this prospectus to “we,” “us,” “our,” “Altimmune,” the “Company” and any applicable prospectus supplements. We have not authorized any other personsimilar designations refer to provide youAltimmune, Inc., together with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information in this prospectus is accurate as of the date appearing on the front cover of this prospectus only and that information contained in any prospectus supplement or document incorporated by reference in this prospectus is only accurate as of the date of such prospectus supplement or document. Our business, financial condition, results of operations and prospects may have subsequently changed.

its subsidiaries.

This prospectus is part of a “shelf” registration statement that we filed with the SEC to register an indeterminate number of shares of common stock, preferred stockSecurities and warrants as may from time to time be offered for sale, either individually or in units, at indeterminate prices (up to an aggregate maximum offering price for all such securities of $100,000,000), using a “shelf” registration process.Exchange Commission (the “SEC”). By using a shelf registration statement, we may offer and sell, from time to time, in one or more offerings, any combination of the securities described in this prospectus.

This prospectus provides you with somea general description of the general terms thatsecurities we may apply to an offering of our securities.offer. Each time we sell securities, under this shelf registration statement, we will provide a prospectus supplement that will contain specific information about the terms and manner of that specific offering, includingoffering. The accompanying prospectus supplement or information incorporated by reference into this prospectus after the number and price (or exercise price)date of the securities to be offered and sold in that offering and the specific manner in which such securities may be offered. Thethis prospectus supplement may also add, to, update or change any of the information contained in this prospectus. To the extent thereAny such information that is a conflict between the information contained ininconsistent with this prospectus on the one hand, and the information contained in the applicable prospectus supplement, on the other hand, you should rely onwill supersede the information in the prospectus supplement.

this prospectus. You should carefully read both this prospectus and the accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information.”

You should rely only on the information we have provided or incorporated by reference into this prospectus, any applicable prospectus supplement and any related free writing prospectus. We have not authorized anyone to provide you with different information. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus.

Neither the delivery of this prospectus nor any sale made under it implies that the information in this prospectus is correct as wellof any date after the date of this prospectus. You should assume that the information in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate only as of the date thereof and that any documentsinformation incorporated by reference in this prospectus, (as described under the heading “Incorporation by Reference”) and/or the applicable prospectus supplement, before you make your investment decision.  The information incorporated by reference includes important business and financial information about us that is not included nor delivered with this document. This information is available without charge on the SEC’s website at www.sec.gov or upon written or oral request to PharmAthene, Inc., One Park Place, Suite 450, Annapolis, Maryland 21401, (410) 269-2600.  If any statement in this prospectus, the applicable prospectus supplement or any related free writing prospectus is accurate only as of the date of the document incorporated by reference, into oneregardless of the time of delivery of this prospectus, any applicable prospectus supplement or any related free writing prospectus, or any sale of a security.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under “Incorporation by Reference.”

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements, and other information with the SEC. The SEC maintains a web site at http://www.sec.gov that contains reports, proxy statements and other information about issuers, such as us, who file electronically with the SEC. Our SEC filings are available on the SEC’s Internet site. We maintain a website at http://www.altimmune.com. Information found on, or accessible through, our website is inconsistentnot a part of, and is not incorporated into, this prospectus supplement or the accompanying prospectus, and you should not consider it part of this prospectus supplement or part of the accompanying prospectus.

Our common stock is listed on the Nasdaq Global Market under the ticker “ALT.”

We have filed with the SEC a registration statement in anotheron FormS-3 under the Securities Act of those documents having1933, as amended (the “Securities Act”), with respect to the securities covered by this prospectus. This prospectus, which is a later date,part of the registration statement, does not contain all of the information set forth in the document havingregistration statement or the later date modifiesexhibits and schedules filed therewith. For further information with respect to us and the securities covered by this prospectus, please see the registration statement and the exhibits filed with the registration statement. A copy of the registration statement and the exhibits filed with the registration statement may be inspected without charge from the SEC as indicated above, or supersedesfrom us as indicated under “Incorporation by Reference.”

INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the earlier statement.

Unless otherwise mentioned or unlessinformation that we file with the context requires otherwise, all referencesSEC. This permits us to “PharmAthene,” the “Company,” “we,” “us,” “our,” and similar terms referdisclose important information to PharmAthene, Inc. and its subsidiaries on a consolidated basis. The phrase “this prospectus” refersyou by referring to these filed documents. Any information referred to in this way is considered part of this prospectus, and any applicableinformation filed with the SEC by us after the date of this prospectus will automatically be deemed to update and supersede this information. We incorporate by reference the following documents that have been filed with the SEC (other than, in each case, documents or information deemed furnished and not filed in accordance with SEC rules, including pursuant to Item 2.02 or Item 7.01 or any related exhibit furnished under Item 9.01(d) of Form8-K, and no such information shall be deemed specifically incorporated by reference hereby):

We also incorporate by reference any future filings (other than information in such documents that is not deemed to be filed) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act until we file a post-effective amendment which indicates the termination of the offering of the securities made by this prospectus.

We will provide to each person, including any beneficial owner, to whom a prospectus is delivered a copy of any or all of the documents that are incorporated by reference into this prospectus supplement unlessbut not delivered with this prospectus, including exhibits that are specifically incorporated by reference in such documents. You may request a copy of such documents at no cost, by writing or telephoning us at the context otherwise requires. Whenever we refer to “you”following address or “yours,” we mean the persons to whom offers are made under this prospectus.telephone number: Altimmune, Inc., 910 Clopper Road, Suite 201S, Gaithersburg, Maryland, Attention: Chief Financial Officer. Our telephone number is(240) 654-1450.

USE OF PROCEEDS

Unless otherwise set forth in our common stock and subject us to additional trading restrictions.

Our common stock is listed on the NYSE MKT, a national securities exchange, which imposes continued listing requirementsprospectus supplement with respect to listed shares. If, however, we fail to satisfy the continued listing standards, such as, for example, the requirement that our shares not trade “for a substantial period of time at a low price per share” or that we not dispose of our principal operating assets or discontinue a substantial portion of our operations, among other requirements, the NYSE MKT may issue another non-compliance letter or initiate delisting proceedings.

If our securities are delisted from trading on the NYSE MKT and we are not able to list our securities on another exchange or to have them quoted on NASDAQ, our securities could be quoted on the OTC Bulletin Board or on the “pink sheets.” As a result, we could face significant adverse consequences including:

Our stock price is volatile.

The market price of our common stock has been, and is expected to continue to be, subject to significant volatility. The value of our common stock may decline regardless of our operating performance or prospects. Factors that may affect our market price include:

Shares that we may issue in the future in connection with certain capital-raising transactions and shares available for future issuance upon exercise of warrants and options could dilute our stockholders and depress the market price of our common stock.

The issuance of our securities in the future may depress the market price of our stock, and any such financing(s) will dilute our existing stockholders.

In addition, as of March 31, 2014, we had outstanding options to purchase approximately 6.9 million shares of common stock (not including restricted shares). Additional shares are reserved for issuance under our 2007 Long-Term Incentive Compensation Plan. Our stock options are generally exercisable for ten years, with a significant portion exercisable either immediately or beginning one year after the date of the grant.

As of May 15, 2014, aggregate gross sales for additional common stock of approximately $4.6 million remained available under the March 25, 2013 controlled equity offering entered into with a sales agent pursuant to which we may offer and sell, from time to time, through the agent shares of our common stock having an aggregate offering price of up to $15,000,000.

We filed two registration statements on Form S-3 (File Nos. 333-161587 and 333-176607) covering the resale of shares issued upon conversion of our 10% convertible notes and issuable upon exercise of related warrants by certain of our affiliates, among other security holders. Both registration statements have been declared effective. Our obligation under the terms of the related registration rights agreement is to keep these registration statements effective. The sale by these security holders of their shares pursuant to the registration statement or otherwise could depress the market price of our common stock.

Finally, as of March 31, 2014, we had issued and outstanding additional warrants to purchase up to approximately 5.6 million shares of common stock.

The issuance or even the expected issuance of a large number of shares of our common stock upon purchase, conversion or exercise of the securities described above could depress the market price of our stock and the issuance of such shares will dilute the stock ownership of our existing stockholders. Shares that we may issue in the future in connection with certain capital-raising transactions and shares available for future issuance upon exercise of warrants and options could dilute our stockholders and depress the market price of our common stock.

We can give no assurances that we will ever pay dividends.

The GE Loan Agreement specifically restricts the declaration or payment of any dividends. We have never paid any dividends on our common stock, and we do not intend to declare any dividends in the foreseeable future. While subject to periodic review, our current policy is to retain all earnings, if any, primarily to finance our future growth. We make no assurances that we will ever pay dividends, cash or otherwise. Whether we pay any dividends in the future will depend on our financial condition, results of operations, and other factors that we will consider.

Our fully-secured GE Loan Agreement is subject to acceleration in specified circumstances, which may result in GE Capital terminating the commitment, accelerating repayment of obligations or taking possession and disposing of any collateral.

In the first quarter 2012, we closed on a senior fully-secured debt facility with GE Capital providing for a $2.5 million term loan and a revolving line of credit of up to $5.0 million based on a percentage of our outstanding qualified accounts receivable. Our obligations under the GE Loan Agreement are secured by a security interest in substantially all of our assets. While the security interest does not, except in limited circumstances, cover our intellectual property, it does cover any proceeds to us from the use of intellectual property. The GE Loan Agreement contains customary representations, warranties and covenants, including limitations on acquisitions, dispositions, incurrence of indebtedness and the granting of security interests. Upon the occurrence and during the continuance of any event of default, GE Capital may, and at the written request of the requisite lenders shall, terminate the commitments under the facilities and declare any or all of the obligations to be immediately due and payable, without demand or notice to us. Any event of default relating to timely payment of debts, insolvency, liquidation, bankruptcy or similar events will result in automatic acceleration. Among the remedies available to GE Capital in case of an event of default are terminating the commitment, accelerating repayment of obligations or taking possession and disposition of any collateral under the GE Loan Agreement.

We owe GE Capital, as of March 31, 2014, an aggregate of approximately $1.5 million under the GE Loan Agreement. As a result of the receipt of the notice that we received from BARDA on April 4, 2014 advising us of its decision to de-scope the current SparVax^® anthrax vaccine contract through a partial termination for convenience, and its subsequent communication, and any further communications that we may receive from BARDA in the future, GE Capital could assert that there has occurred an event of default under the GE Loan Agreement, which would allow GE Capital to terminate the commitment and the loans under the GE Loan Agreement and declare any or all of the obligations thereunder to be immediately due and payable.

USE OF PROCEEDS

We will retain broad discretion over the use of net proceeds to us from the sale of ourthe particular securities offered hereby.  Except as may be otherwise described in ato which such prospectus supplement relates, we currently anticipate using anyintend to use the net proceeds to usfrom the sale of the offered securities for general corporate purposes, which may includeincluding repayment or redemption of outstanding debt or preferred stock, the possible acquisition of related businesses or assets thereof, and working capital research and development expenses, general and administrative expenses, and capital expenditures.  We may also use a portion of the net proceeds to acquire or invest in businesses, products and technologies that are complementary to our own, although we have no present definitive commitments or agreements for any such transactions on the date of this Registration Statement.   The amounts and timing of our actual expenditures for each purpose may vary significantly depending upon numerous factors, including the actual amount of proceeds we receive, the status of our research and product development efforts, regulatory approvals, competition and economic or other conditions.needs.

Pending the application of such proceeds, we may invest the proceeds in short-term, interest bearing, investment-grade marketable securities or money market obligations.

DESCRIPTION OF COMMON STOCK

Under our Amended and Restated Certificate of Incorporation, as amended, to which we refer as our “charter,” we are currently authorized to issue 100,000,000200,000,000 shares of common stock, par value $.0001 per share. As of May 15, 2014,March 27, 2019, we had 54,542,01513,451,105 shares of common stock outstanding.

Holders of our common stock are entitled to one vote for each share of common stock held of record on all matters to be voted on by stockholders, except as otherwise provided by law or in any preferred stock designation. Our bylaws specify that, except as otherwise required by law or our charter, the presence in person or by proxy of holders of a majority of the shares entitled to vote at a meeting of stockholders will be necessary, and will constitute a quorum, for the transaction of business at such meeting. Our bylaws furthermore specify that all elections of directors will be determined by a plurality of the votes and that, except as otherwise provided by law or in the charter or bylaws, any other matter will be determined by the vote of a majority of the shares which are voted with regard to it. Holders of our common stock have no conversion, preemptive or other subscription rights and there are no sinking fund or redemption provisions applicable to the common stock.

There is no cumulative voting with respect to the election of directors, with the result that the holders of more than 50% of the shares voting for the election of directors can elect all of the directors then up for election. Holders of our common stock are entitled to receive dividends when, as and if declared by our Boardboard of Directorsdirectors out of funds legally available therefor. In the event of our liquidation, dissolution or winding up, the holders of common stock are entitled to share in all assets remaining which are available for distribution to them after payment of liabilities and after provision has been made for each class of stock, if any, having preference over the common stock.

Transfer Agent

The transfer agent and registrar for the common stock is Continental Stock Transfer & Trust Company, New York, New York.

DESCRIPTION OF PREFERRED STOCK

Under our charter, we are currently authorized to issue 1,000,000 shares of preferred stock, par value $.0001 per share. As of the date of this prospectus, we had no shares of preferred stock outstanding.

Under our charter, our Boardboard of Directorsdirectors is expressly granted authority to issue shares of preferred stock, in one or more series, and to fix for each series such voting powers, full or limited, and such designations, preferences and relative, participating, optional or other special rights and such qualifications, limitations or restrictions as it may determine in the resolution or resolutions providing for the issue of such series (to which we also refer as a “preferred stock designation”) and as may be permitted by the Delaware General Corporation Law. The number of authorized shares of preferred stock may be increased or decreased (but not below the number of shares of preferred stock then outstanding) by the affirmative vote of the holders of a majority of the voting power of all of the then outstanding shares of our capital stock entitled to vote generally in the election of directors, voting together as a single class, without a separate vote of the holders of the preferred stock, or any series of preferred stock, unless a vote of any such holders is required pursuant to any preferred stock designation.

This section describes the general terms of our preferred stock to which any prospectus supplement may relate. A prospectus supplement will describe the terms relating to any preferred stock to be offered by us in greater detail, and may provide information that is different from the information described in this prospectus. If the information in the prospectus supplement with respect to the particular preferred stock being offered differs from the information in this prospectus, you should rely on the information in the prospectus supplement. A copy

of our charter has been incorporated by reference from our filings with the SEC as an exhibit to the registration statement of which this prospectus is a part. A certificate of designations will specify the terms of the preferred stock being offered, and will be filed as an exhibit to the registration statement of which this prospectus is a part or incorporated by reference from a report that we file with the SEC.

The rights and terms relating to any new series of preferred stock could adversely affect the voting power or other rights of the holders of the common stock or could be utilized, under certain circumstances, as a method of discouraging, delaying or preventing a change in control of the Company.

The following description of our preferred stock, together with any description of our preferred stock in a related prospectus supplement, summarizes the material terms and provisions of the preferred stock that we may sell under this prospectus. We urge you to read the applicable prospectus supplement(s) related to the particular series of preferred stock that we sell under this prospectus and to the actual terms and provisions contained in our charter (certificate of designations) and bylaws, each as amended from time to time.

Terms

Our Boardboard of Directorsdirectors will fix the rights, preferences, privileges, qualifications and restrictions of the preferred stock of each series that we sell under this prospectus and applicable prospectus supplements in the certificate of designations relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part or incorporate by reference the form of any certificate of designations that describes the terms of the series of preferred stock we are offering in connection with the issuance of the related series of preferred stock. This description of the preferred stock in the certificate of designations and any applicable prospectus supplement may include:

Rank

As set forth in the applicable supplement to this prospectus, supplement, shares of our preferred stock may rank, with respect to payment of distributions and rights upon our liquidation, dissolution or winding up, and allocation of our earnings and losses:

Distributions

Subject to any preferential rights of any outstanding stock or series of stock, holders of our preferred stock may be entitled to receive distributions, when and as authorized by our Boardboard of Directors,directors, out of legally available funds, and share pro rata based on the number of shares of preferred stock, common stock and other equity securities outstanding.

Voting Rights

As indicated in the applicable supplement to this prospectus, supplement, and as otherwise required under Delaware law, holders of our preferred stock may or may not have voting rights.

Liquidation Preference

As indicated in the applicable supplement to this prospectus, supplement, upon the voluntary or involuntary liquidation, dissolution or winding up of our affairs, then, before any distribution or payment shall be made to the holders of any common stock or any other class or series of stock ranking junior to the preferred stock in our distribution of assets upon any liquidation, dissolution or winding up, the holders of each series of our preferred stock may be entitled to receive, after payment or provision for payment of our debts and other liabilities, out of our assets legally available for distribution to stockholders,shareholders, liquidating distributions in the amount of the liquidation preference per share (set forth in the applicable prospectus supplement)supplement to this prospectus), plus an amount, if applicable, equal to all distributions accrued and unpaid thereon (which shall not include any accumulation in respect of unpaid distributions for prior distribution periods if the preferred stock does not have a cumulative distribution). After payment of the full amount of the liquidating distributions to which they may be entitled, the holders of preferred stock may have no right or claim to any of our remaining assets. In the event that, upon our voluntary or involuntary liquidation, dissolution or winding up, the legally available assets are insufficient to pay the amount of the liquidating distributions on all of our outstanding preferred stock and the corresponding amounts payable on all of our stock of other classes or series of equity security ranking on a parity with the preferred stock in the distribution of assets upon liquidation, dissolution or winding up, then the holders of our preferred stock and all other such classes or series of equity securities may share ratably in the distribution of assets in proportion to the full liquidating distributions to which they would otherwise be respectively entitled.

If the liquidating distributions are made in full to all holders of preferred stock, our remaining assets may be distributed among the holders of any other classes or series of equity security ranking junior to the preferred stock upon our liquidation, dissolution, or winding up, according to their respective rights and preferences and in each case according to their respective number of shares of stock.

Conversion Rights

The terms and conditions, if any, upon which shares of any series of preferred stock are convertible into, such as common stock, debt securities, warrants or units consisting of one or more of such securities will be set forth in the applicable prospectus supplement.supplement to this prospectus. These terms will include the amount and type of security into which the shares of preferred stock are convertible, the conversion price (or manner of calculation thereof), the conversion period, provisions as to whether conversion will be at the option of the holders of the preferred stock or us, the events, if any, requiring an adjustment of the conversion price and provisions, if any, affecting conversion in the event of the redemption of that preferred stock.

Redemption

If so provided in the applicable prospectus supplement to this prospectus, our preferred stock will be subject to mandatory redemption or redemption at our option, in whole or in part, in each case upon the terms, at the times and at the redemption prices set forth in such supplement to this prospectus.

DESCRIPTION OF DEPOSITARY SHARES

The following description of the depositary shares does not purport to be complete and is subject to and qualified in its entirety by the Deposit Agreement and the depositary receipt relating to the preferred stock that is attached to the Deposit Agreement. You should read these documents as they, and not this description, define your rights as a holder of depositary shares. Forms of these documents have been filed with the SEC as an exhibit to the registration statement of which this prospectus forms a part.

General

If we elect to offer fractional interests in shares of preferred stock, we will provide for the issuance by a depositary to the public of receipts for depositary shares. Each depositary share will represent fractional interests of preferred stock. We will deposit the shares of preferred stock underlying the depositary shares under a Deposit Agreement between us and a bank or trust company selected by us. The bank or trust company must have its principal office in the United States and a combined capital and surplus of at least $50 million. The depositary receipts will evidence the depositary shares issued under the Deposit Agreement.

The Deposit Agreement will contain terms applicable to the holders of depositary shares in addition to the terms stated in the depositary receipts. Each owner of depositary shares will be entitled to all the rights and preferences of the preferred stock underlying the depositary shares in proportion to the applicable fractional interest in the underlying shares of preferred stock. The depositary will issue the depositary receipts to individuals purchasing the fractional interests in shares of the related preferred stock according to the terms of the offering described in a prospectus supplement.

Dividends and Other Distributions

The depositary will distribute all cash dividends or other cash distributions received for the preferred stock to the entitled record holders of depositary shares in proportion to the number of depositary shares that the holder owns on the relevant record date. The depositary will distribute only an amount that can be distributed without attributing to any holder of depositary shares a fraction of one cent. The depositary will add the undistributed balance to and treat it as part of the next sum received by the depositary for distribution to holders of depositary shares.

If there is anon-cash distribution, the depositary will distribute property received by it to the entitled record holders of depositary shares, in proportion, insofar as possible, to the number of depositary shares owned by the holders, unless the depositary determines, after consultation with us, that it is not feasible to make such distribution. If this occurs, the depositary may, with our approval, sell such property and distribute the net proceeds from the sale to the holders. The Deposit Agreement also will contain provisions relating to how any subscription or similar rights that we may offer to holders of the preferred stock will be available to the holders of the depositary shares.

Conversion, Exchange and Redemption

If any series of preferred stock underlying the depositary shares may be converted or exchanged, each record holder of depositary receipts will have the right or obligation to convert or exchange the depositary shares represented by the depositary receipts.

Whenever we redeem shares of preferred stock held by the depositary, the depositary will redeem, at the same time, the number of depositary shares representing the preferred stock. The depositary will redeem the depositary shares from the proceeds it receives from the corresponding redemption, in whole or in part, of the applicable series of preferred stock. The depositary will mail notice of redemption to the record holders of the depositary shares that are to be redeemed between 30 and 60 days before the date fixed for redemption. The redemption price per depositary share will be equal to the applicable fraction of the redemption price per share on

the applicable series of preferred stock. If less than all the depositary shares are to be redeemed, the depositary will select which shares to be redeemed by lot, proportionate allocation or any other method.

After the date fixed for redemption, the depositary shares called for redemption will no longer be outstanding. When the depositary shares are no longer outstanding, all rights of the holders will end, except the right to receive money, securities or other property payable upon redemption.

Voting

When the depositary receives notice of a meeting at which the holders of the preferred stock are entitled to vote, the depositary will mail the particulars of the meeting to the record holders of the depositary shares. Each record holder of depositary shares on the record date may instruct the depositary on how to vote the shares of preferred stock underlying the holder’s depositary shares. The depositary will try, if practical, to vote the number of shares of preferred stock underlying the depositary shares according to the instructions. The depositary will abstain from voting shares of the preferred stock to the extent it does not receive specific instructions from the holders of depositary shares representing such preferred stock. We will agree to take all reasonable action requested by the depositary to enable it to vote as instructed.

Record Date

Whenever (1) any cash dividend or other cash distribution shall become payable, any distribution other than cash shall be made, or any rights, preferences or privileges shall be offered with respect to the preferred stock, or (2) the depositary shall receive notice of any meeting at which holders of preferred stock are entitled to vote or of which holders of preferred stock are entitled to notice, or of the mandatory conversion of or any election on our part to call for the redemption of any preferred stock, the depositary shall in each such instance fix a record date (which shall be the same as the record date for the preferred stock) for the determination of the holders of depositary receipts (x) who shall be entitled to receive such dividend, distribution, rights, preferences or privileges or the net proceeds of the sale thereof or (y) who shall be entitled to give instructions for the exercise of voting rights at any such meeting or to receive notice of such meeting or of such redemption or conversion, subject to the provisions of the Deposit Agreement.

Amendments

We and the depositary may agree to amend the Deposit Agreement and the depositary receipt evidencing the depositary shares. Any amendment that (a) imposes or increases certain fees, taxes or other charges payable by the holders of the depositary shares as described in the Deposit Agreement or (b) otherwise prejudices any substantial existing right of holders of depositary shares, will not take effect until 30 days after the depositary has mailed notice of the amendment to the record holders of depositary shares. Any holder of depositary shares that continues to hold its shares at the end of the30-day period will be deemed to have agreed to the amendment.

Termination

We may direct the depositary to terminate the Deposit Agreement by mailing a notice of termination to holders of depositary shares at least 30 days prior to termination. In addition, a Deposit Agreement will automatically terminate if:

The depositary may likewise terminate the Deposit Agreement if at any time 60 days shall have expired after the depositary shall have delivered to us a written notice of its election to resign and a successor depositary

shall not have been appointed and accepted its appointment. If any depositary receipts remain outstanding after the date of termination, the depositary thereafter will discontinue the transfer of depositary receipts, will suspend the distribution of dividends to the holders thereof, and will not give any further notices (other than notice of such termination) or perform any further acts under the Deposit Agreement except as provided below and except that the depositary will continue (1) to collect dividends on the preferred stock and any other distributions with respect thereto and (2) to deliver the preferred stock together with such dividends and distributions and the net proceeds of any sales of rights, preferences, privileges or other property, without liability for interest thereon, in exchange for depositary receipts surrendered. At any time after the expiration of two years from the date of termination, the depositary may sell the preferred stock then held by it at public or private sales, at such place or places and upon such terms as it deems proper and may thereafter hold the net proceeds of any such sale, together with any money and other property then held by it, without liability for interest thereon, for the pro rata benefit of the holders of depositary receipts which have not been surrendered.

Payment of Fees and Expenses

We will pay all fees, charges and expenses of the depositary, including the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary shares will pay transfer and other taxes and governmental charges and any other charges as are stated in the Deposit Agreement for their accounts.

Resignation and Removal of Depositary

At any time, the depositary may resign by delivering notice to us, and we may remove the depositary. Resignations or removals will take effect upon the appointment of a successor depositary and its acceptance of the appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50 million.

Reports

The depositary will forward to the holders of depositary shares all reports and communications from us that are delivered to the depositary and that we are required by law, the rules of an applicable securities exchange or our amended and restated certificate of incorporation to furnish to the holders of the preferred stock. Neither we nor the depositary will be liable if the depositary is prevented or delayed by law or any circumstances beyond its control in performing its obligations under the Deposit Agreement. The Deposit Agreement limits our obligations and the depositary’s obligations to performance in good faith of the duties stated in the Deposit Agreement. Neither we nor the depositary will be obligated to prosecute or defend any legal proceeding connected with any depositary shares or preferred stock unless the holders of depositary shares requesting us to do so furnish us with satisfactory indemnity. In performing our obligations, we and the depositary may rely upon the written advice of our counsel or accountants, on any information that competent people provide to us and on documents that we believe are genuine.

DESCRIPTION OF DEBT SECURITIES

We may issue debt securities under one or more trust indentures to be executed by us and a specified trustee. The terms of the debt securities will include those stated in the indenture and those made a part of the indenture by reference to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). The indentures will be qualified under the Trust Indenture Act.

The following description sets forth certain anticipated general terms and provisions of the debt securities to which an accompanying prospectus supplement may relate. The particular terms of the debt securities offered by an accompanying prospectus supplement (which terms may be different than those stated below) and the extent, if any, to which such general provisions may apply to the debt securities so offered will be described in the prospectus supplement relating to such debt securities. Accordingly, for a description of the terms of a particular issue of debt securities, investors should review both the accompanying prospectus supplement relating thereto and the following description. A form of the indenture has been filed as an exhibit to the registration statement of which this prospectus is a part.

The debt securities will be our direct obligations and may be either senior debt securities or subordinated debt securities. The indebtedness represented by subordinated securities will be subordinated in right of payment to the prior payment in full of our senior debt (as defined in the applicable indenture).

Except as set forth in the applicable indenture and described in an accompanying prospectus supplement relating thereto, the debt securities may be issued without limit as to aggregate principal amount, in one or more series, secured or unsecured, in each case as established from time to time in or pursuant to authority granted by a resolution of the board of trustees or as established in the applicable indenture. All debt securities of one series need not be issued at the same time and, unless otherwise provided, a series may be reopened, without the consent of the holders of the debt securities of such series, for issuance of additional debt securities of such series.

The accompanying prospectus supplement relating to any series of debt securities being offered will contain their specific terms, including, without limitation:

The debt securities may provide for less than the entire principal amount thereof to be payable upon declaration of acceleration of the maturity thereof. Special federal income tax, accounting and other considerations applicable to debt securities will be described in the accompanying prospectus supplement.

The applicable indenture may contain provisions that would limit our ability to incur indebtedness or that would afford holders of debt securities protection in the event of a highly leveraged or similar transaction involving us or in the event of a change of control.

Investors should review the accompanying prospectus supplement for information with respect to any deletions from, modifications of or additions to the events of default or covenants that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

Merger, Consolidation or Sale

The applicable indenture will provide that we may consolidate with or merge into, or convey, transfer or lease all or substantially all of our properties and assets to any other person (as defined therein), provided that:

Covenants

The applicable indenture will contain covenants requiring us to take certain actions and prohibiting us from taking certain actions. The covenants with respect to any series of debt securities will be described in the accompanying prospectus supplement.

Events of Default, Notice and Waiver

Each indenture will describe specific “events of default” with respect to a series of debt securities issued under the indenture. These “events of default” are likely to include (with grace and cure periods):

If an event of default resulting from certain events of bankruptcy described in the indenture occurs, all outstanding debt securities of that series will become due and payable immediately. If any other event of default under any indenture with respect to debt securities of any series at the time outstanding occurs and is continuing, then the applicable trustee or the holders of not less than 25% of the principal amount of the outstanding debt securities of that series may declare the principal amount (or, if the debt securities of that series are original issue discount securities or indexed securities, such portion of the principal amount as may be specified in the terms thereof) of all the debt securities of that series to be due and payable immediately by written notice thereof to us (and to the applicable trustee if given by the holders). However, at any time after such a declaration of acceleration with respect to debt securities of such series (or of all debt securities then outstanding under any indenture, as the case may be) has been made, the holders of not less than a majority in principal amount of outstanding debt securities of such series (or of all debt securities then outstanding under the applicable indenture, as the case may be) may rescind and annul such declaration and its consequences if:

Each indenture also will provide that the holders of not less than a majority in principal amount of the outstanding debt securities of any series (or of all debt securities then outstanding under the applicable indenture, as the case may be) may waive any past default with respect to the series and its consequences, except a:

Each trustee will be required to give notice to the holders of debt securities within a certain number of days of a default under the applicable indenture unless the default has been cured or waived; provided, however, that the trustee may withhold notice to the holders of any series of debt securities of any default with respect to the series (except a default in the payment of the principal of (or premium, if any) or interest on any debt security of the series or in the payment of any sinking fund installment in respect of any debt security of the series) if specified responsible officers of the trustee consider withholding the notice to be in the interest of the holders.

Each indenture will prohibit the holders of debt securities of any series from instituting any proceedings, judicial or otherwise, with respect to the indenture or for any remedy thereunder, except in the case of failure of the applicable trustee, for a certain period of time after the trustee has received a written request to institute proceedings in respect of an event of default from the holders of not less than a majority in principal amount of the outstanding debt securities of such series, as well as the furnishing of indemnity reasonably satisfactory to it. This provision will not prevent any holder of debt securities from instituting a suit to enforce the payment of the principal of (and premium, if any) and interest on the debt securities at the respective due dates thereof.

Subject to the indenture, no trustee will be under any obligation to exercise any of its rights or powers under an indenture at the request or direction of any holders of any series of debt securities then outstanding, unless the holders furnish the trustee thereunder reasonable security or indemnity. The holders of not less than a majority in principal amount of the outstanding debt securities of any series (or of all debt securities then outstanding under an indenture, as the case may be) will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the applicable trustee, or of exercising any trust or power conferred upon the trustee. However, a trustee may refuse to follow any direction, which is in conflict with any law or the applicable indenture, which may involve the trustee in personal liability or which may be unduly prejudicial to the holders of debt securities of such series not joining therein.

Within a certain period of time of the close of each fiscal year, we will be required to deliver to each trustee, a certificate, signed by one of several specified officers, stating whether or not the officer has knowledge of any default under the applicable indenture and, if so, specifying each default and the nature and status thereof.

Modification of the Indenture

The indenture will likely provide that it may be modified or amended, with the consent of the holders of not less than a majority in principal amount of each series of the outstanding debt securities issued under the indenture affected by the modification or amendment, provided that no modification or amendment may, without the consent of each affected holder of the debt securities:

A record date may be set for any act of the holders with respect to consenting to any amendment.

The holders of not less than a majority in principal amount of the outstanding debt securities of each series affected thereby will have the right to waive our compliance with certain covenants in the indenture. Each indenture will contain provisions for convening meetings of the holders of debt securities of a series to take permitted action. Under certain circumstances, we and the trustee may make modifications and amendments to an indenture without the consent of any holders of outstanding debt securities.

Redemption of Debt Securities

The debt securities may be subject to optional or mandatory redemption on terms and conditions described in the applicable accompanying prospectus supplement.

Conversion of Debt Securities

The terms and conditions, if any, upon which any debt securities are convertible or into our common stock or preferred stock will be set forth in the applicable accompanying prospectus supplement. The terms will include:

Subordination

Upon any distribution to our creditors in a liquidation, dissolution or reorganization, the payment of the principal of and interest on any subordinated securities will be subordinated to the extent provided in the applicable indenture to the prior payment in full of all senior securities. No payment of principal or interest will be permitted to be made on subordinated securities at any time if any payment default or any other default which permits accelerations exists. After all senior securities are paid in full and until the subordinated securities are paid in full, holders of subordinated securities will be subrogated to the right of holders of senior securities to the extent that distributions otherwise payable to holders of subordinated securities have been applied to the payment of senior securities. By reason of any subordination, in the event of a distribution of assets upon our insolvency, some of our general creditors may recover more, ratably, than holders of subordinated securities. The accompanying prospectus supplement or the information incorporated herein by reference will contain the approximate amount of senior securities outstanding as of the end of our most recent fiscal quarter.

Global Debt Securities

The debt securities of a series may be issued in whole or in part in global form. The global securities will be deposited with a depositary, or with a nominee for a depositary, identified in the accompanying prospectus supplement. In this case, one or more global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal amount of outstanding debt securities of the series to be represented by the global security or securities. Unless and until it is exchanged in whole or in part for debt securities in definitive form, a global security may not be transferred except as a whole by the depositary for the global security to a nominee of the depositary or by a nominee of the depositary to the depositary or another nominee of the depositary or by the depositary or any nominee to a successor of the depositary or a nominee of the successor.

The specific material terms of the depositary arrangement with respect to any portion of a series of debt securities to be represented by a global security will be described in the applicable accompanying prospectus supplement. We anticipate that the following provisions will apply to all depositary arrangements.

Upon the issuance of a global security, the depositary for the global security will credit, on its book-entry registration and transfer system, the respective principal amounts of the debt securities represented by the global security to the accounts of persons or participants that have accounts with the depositary. The accounts to be credited will be designated by any underwriters or agents participating in the distribution of the debt securities. Ownership of beneficial interests in a global security will be limited to participants or persons that may hold interests through participants. Ownership of beneficial interests in the global security will be shown on, and the transfer of that ownership will be effected only through, records maintained by the depositary for the global security, with respect to interests of participants, or by participants or persons that hold through participants, with respect to interests of persons other than participants. So long as the depositary for a global security, or its nominee, is the registered owner of the global security, the depositary or the nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by the global security for all purposes under the indenture; provided, however, that for purposes of obtaining any consents or directions required to be given by the holders of the debt securities, we, the trustee and our agents will treat a person as the holder of the principal amount of debt securities as specified in a written statement of the depositary. Except as set forth herein or otherwise provided in the accompanying prospectus supplement, owners of beneficial interests in a global security will not be entitled to have the debt securities represented by the global security registered in their names, will not receive physical delivery of the debt securities in definitive form and will not be considered the owners or holders thereof under the indenture.

Principal, premium, if any, and interest payments on debt securities represented by a global security registered in the 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 global security. Neither we, the trustee nor any paying agent for the debt securities will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the global security or for maintaining, supervising or reviewing any records relating to the beneficial ownership interests.

We expect that the depositary for any debt securities represented by a global security, upon receipt of any payment of principal, premium, if any, or interest will immediately credit participants’ accounts with payments in amounts proportionate to their respective beneficial interests in the principal amount of the global security as shown on the records of the depositary. We also expect that payments by participants will be governed by standing instructions and customary practices, as is now the case with the securities held for the accounts of customers registered in “street names” and will be the responsibility of the participants.

If the depositary for any debt securities represented by a global security is at any time unwilling or unable to continue as depositary and a successor depositary is not appointed by us within the period of time set forth in the indenture, we will issue the debt securities in definitive form in exchange for the global security. In addition, we

may at any time, and in our sole discretion, determine not to have any of the debt securities of a series represented by one or more global securities and, in that event, will issue debt securities of the series in definitive form in exchange for all of the global security or securities representing the debt securities.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York.

DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements, summarizes the material terms and provisions of the warrants that we may offer under this prospectus. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The terms of any warrants offered under a prospectus supplement may differ from the terms described below.

We will file as exhibits 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 warrant agreement, which may include a form of warrant certificate, that describes the terms of the particular series of warrants we are offering. The following summary of material provisions of the warrants and the warrant agreements are subject to all the provisions of the warrant agreement and warrant certificate applicable to a particular series of warrants. We urge you to read the applicable prospectus supplements related to the particular series of warrants that we sell under this prospectus, as well as the complete warrant agreements and/or warrant certificates that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms relating to warrants being offered, which may include:

Before exercising their warrants, holders of warrants will likely not have any of the rights of holders of the securities purchasable upon such exercise, including, in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or payments upon our liquidation, dissolution or winding up of our affairs or to exercise voting rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise

specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Holders of the warrants may exercise the warrants by delivering the warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent in immediately available funds, as provided in the applicable prospectus supplement. We intend to set forth in any warrant agreement and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to the warrant agent.

Upon receipt of the required payment and any warrant certificate or other form required for exercise properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants represented by the warrant or warrant certificate are exercised, then we will issue a new warrant or warrant certificate for the remaining amount of warrants. If we so indicate in the applicable prospectus supplement, holders of the warrants may surrender securities as all or part of the exercise price for warrants.

DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS

DescriptionsWe may issue stock purchase contracts, representing contracts obligating holders to purchase from us, and requiring us to sell to the holders, a specified number of shares of common stock at a future date or dates. The price per share of common stock may be fixed at the time the stock purchase contracts are issued or may be determined by reference to a specific formula set forth in the stock purchase contracts. The stock purchase contracts may be issued separately or as a part of units, or stock purchase units, consisting of a stock purchase contract and either (x) senior debt securities, senior subordinated debt securities, subordinated debt securities or junior subordinated debt securities, or (y) debt obligations of third parties, including U.S. Treasury securities, in each case, securing the holder’s obligations to purchase the common stock under the stock purchase contracts. The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase contracts or vice versa, and such payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations thereunder in a specified manner and in certain outstanding warrants are incorporated hereincircumstances we may deliver newly issued prepaid stock purchase contracts, or prepaid securities, upon release to a holder of any collateral securing such holder’s obligations under the original stock purchase contract.

The applicable prospectus supplement will describe the terms of any stock purchase contracts or stock purchase units and, if applicable, prepaid securities. The description in the prospectus supplement will not purport to be complete and will be qualified in its entirety by reference to the Current Reports on Form 8-K filed on each of March 23, 2009, April 7, 2010, July 20, 2010stock purchase contracts, the collateral arrangements and June 10, 2011.depositary arrangements, if applicable, relating to such stock purchase contracts or stock purchase units and, if applicable, the prepaid securities and the document pursuant to which such prepaid securities will be issued.

PLAN OF DISTRIBUTION

WeAltimmune may sell thecommon stock, preferred stock, depositary shares, debt securities, covered by this prospectus from time to time. Registration of our securities covered by this prospectus does not mean, however, that those securities will necessarily be offeredwarrants, stock purchase contracts or sold.

We may sell the securities covered by this prospectus:

We may sell the securities from time to timestock purchase units in one or more transactions at a fixed price or prices, which may be changedof the following ways from time to time, attime:

Altimmune may also sell it securities, including shares of its common stock, in one or more of the following transactions: (i) block transactions (which may involve crosses) in which a broker-dealer may sell all or a portion of such shares as agent, but may position and resell all or a portion of the block as principal to facilitate the transaction; (ii) purchases by any such broker-dealer as principal, and resale by such broker-dealer for its own account pursuant to an accompanying prospectus supplement; (iii) a special offering, an exchange distribution or a secondary distribution in accordance with applicable Nasdaq Global Market or other stock exchange, quotation system orover-the-counter market prices prevailing atrules; (iv) ordinary brokerage transactions and transactions in which any such broker-dealer solicits purchasers; (v) sales “at the times of sale, at prices relatedmarket” to or through a market maker or into an existing trading market, on an exchange or otherwise, for such prevailingshares; and (vi) sales in other ways not involving market prices,makers or at negotiated prices. established trading markets.

For each offering of securities, hereunder, wethe applicable prospectus supplement or other offering materials relating to the offering will describe the method of distribution of such securities in a prospectus supplement. The prospectus supplements will describeset forth the terms of such offering, including:

Any initial public offering prices, discounts or concessions allowed or reallowed or paid to dealers may changebe changed from time to time.

If underwriters are used in the sale, the underwriters will acquire the offered securities for their own account and may resell them from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. The offered securities may be offered either to the public through underwriting syndicates represented by one or more managing underwriters or by one or more underwriters without a syndicate. Unless otherwise set forth in a prospectus supplement, the obligations of the underwriters to purchase any series of securities will be subject to certain conditions precedent, and the underwriters will be obligated to purchase all of such series of securities, if any are purchased.

In connection with any particular offering pursuant to this prospectus, an underwriter may engage in stabilizing transactions, over-allotment transactions, syndicate covering transactionsunderwritten offerings of the offered securities and penalty bids in accordance with Regulation M underapplicable law and industry practice, underwriters may over-allot or effect transactions that stabilize, maintain or otherwise affect the Exchange Act.

Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price.

Over-allotment involves sales by an underwriter of shares in excessmarket price of the number of shares an underwriter is obligated to purchase, which creates a syndicate short position.  The short position may be either a covered short position or a naked short position.  In a covered short position, the number of shares over-allotted by an underwriter is not greater than the number of sharesoffered securities at levels above those that it may purchase in the over-allotment option.  In a naked short position, the number of shares involved is greater than the number of shares in the over-allotment option.  An underwriter may close out any short position by either exercising its over-allotment option and/or purchasing shares in the open market.

Syndicate covering transactions involve purchases of common stockmight otherwise prevail in the open market, afterincluding by entering stabilizing bids, effecting syndicate covering transactions or imposing penalty bids, each of which is described below:

These stabilizing transactions, syndicate covering transactions and penalty bids may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of the common stock.  As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market.  These transactions may be effected on the NYSE MKTNew York Stock Exchange, in theover-the-counter market, or otherwise and, if commenced, may be discontinued at any time.  We make no representation or prediction asotherwise. Underwriters are not required to the direction or magnitude of any effect thatengage in any of these activities, may have on the price of our common stock or to continue such activities if applicable, the price for any of our other securities. For a description of these activities, see the information under the heading “Underwriting” or “Plan of Distribution” in the applicable prospectus supplement.commenced.

If we use dealersa dealer is used in the sale, of securities, weAltimmune will sell thesuch offered securities to the dealersdealer, as principals. Theyprincipal. The dealer may then resell thosethe offered securities to the public at varying prices to be determined by the dealersthat dealer at the time offor resale. We will include in the prospectus supplement theThe names of the dealers and the terms of the transaction will be set forth in the prospectus supplement relating to that transaction.

WeOffered securities may sell securitiesbe sold directly by Altimmune to one or more institutional purchasers, or through agents we designatedesignated by Altimmune from time to time. We will name anytime, at a fixed price or prices, which may be changed, or at varying prices determined at the time of sale. Any agent involved in the offering andoffer or sale of the offered securities and wein respect of which this prospectus is delivered will describebe named, and any commissions payable by usAltimmune to thesuch agent will be set forth, in the prospectus supplement.supplement relating to that offering. Unless theotherwise indicated in such prospectus supplement, states otherwise, any such agent will actbe acting on a best-effortsbest efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

We may provide underwritersUnderwriters, dealers and agents may be entitled under agreements entered into with us to indemnification by us against certain civil liabilities, related to this offering, including liabilities under the Securities Act, or to contribution with respect to payments that the underwriters, dealers or agents may be required to make in respect thereof. Underwriters, dealers and agents may be customers of, engage in transactions with, respect to such liabilities.or perform services for us and our affiliates in the ordinary course of business.

Any preferredOther than our common stock, we offerwhich is listed on the Nasdaq Global Market, each of the securities issued hereunder will representbe a new issue of securities, withwill have no establishedprior trading market.market, and may or may not be listed on a national securities exchange. Any common stock sold pursuant to a prospectus supplement will be listed on the Nasdaq Global Market, subject to official notice of issuance. Any underwriters to whom Altimmune sells securities for public offering and sale may make a market in thesethe securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guaranteeassure you that there will be a market for the liquidity of the trading markets for theseoffered securities.

Underwriters, broker-dealers or agents who may become involved in the sale of our securities may engage in transactions with and perform other services for us in the ordinary course of their business for which they receive compensation.

LEGAL MATTERS

The validityUnless otherwise stated in an accompanying prospectus supplement, Morrison & Foerster LLP, Boston, Massachusetts, will provide us with an opinion as to the legality of the securities offered hereby has been passed upon for us by Dentons US LLP, New York, New York.under this prospectus. Counsel representing any underwriters, dealers or agents will be named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of PharmAthene,Altimmune, Inc. appearing in PharmAthene,Altimmune, Inc.’s Annual Report (Form10-K) for the year ended December 31, 2013, and the effectiveness of PharmAthene, Inc.’s internal control over financial reporting as of December 31, 2013,2018, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reportsreport thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance uponon such reportsreport given on the authority of suchsaid firm as experts in accounting and auditing.

$100,000,000

250,000,000

Common Stock

Preferred Stock

Depositary Shares

Debt Securities

Warrants

Stock Purchase Contracts

Stock Purchase Units

PROSPECTUS

The date of this prospectus is                 , 2014.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a “shelf” registration statement on Form S-3 that we filed with the U.S. Securities and Exchange Commission (SEC) on May 23, 2014.

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 the extent there is a conflict between the information contained in this prospectus, on the one hand, and the information contained in any document incorporated by reference herein or therein, on the other hand, you should rely on the information in this prospectus.

You should read this prospectus, the documents incorporated by reference in this prospectus and any free writing prospectus that we have authorized for use in connection with this offering before making an investment decision. You should also read and consider the information in the documents referred to in the sections of this prospectus entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.”

You should rely only on the information contained or incorporated by reference in this prospectus and any free writing prospectus that we have authorized for use in connection with this offering. We have not authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it.

We are not making an offer to sell the securities covered by this prospectus in any jurisdiction where the offer or sale is not permitted.

The information appearing in this prospectus, the documents incorporated by reference in this prospectus and any free writing prospectus that we have authorized for use in connection with this offering is accurate only as of its respective date, regardless of the time of delivery of the respective document or of any sale of securities covered by this prospectus. You should not assume that the information contained in or incorporated by reference in this prospectus, or in any free writing prospectus that we have authorized for use in connection with this offering, is accurate as of any date other than the respective dates thereof.

Unless otherwise mentioned or unless the context requires otherwise, all references to “PharmAthene,” the "Company,” “we,” “us,” “our,” and similar terms refer to PharmAthene, Inc. and its subsidiaries on a consolidated basis. The phrase “this prospectus” refers to this prospectus, unless the context otherwise requires. Whenever we refer to “you” or “yours,” we mean the persons to whom offers are made under this prospectus.

SPECIAL NOTE REGARDING FORWARD-LOOKING INFORMATION

This prospectus and any related prospectus and the information incorporated by reference herein and therein contain forward-looking statements within the meaning of Section 27A of the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended. This information may involve known and unknown risks, uncertainties and other factors that are difficult to predict and may cause our actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by any forward-looking statements.  These risks, uncertainties and other factors include, but are not limited to, risks associated with the following:

as well as risks detailed under the caption “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2013, Quarterly Report on Form 10-Q for the quarter ended March 31, 2014 and in our other reports filed with the SEC from time to time thereafter. In particular, in its May 2013 decision, the Delaware Supreme Court reversed the remedy ordered by the Delaware Court of Chancery which awarded PharmAthene 50% of all net profits (as defined in the court's final judgment) related to the sale of Arestvyr^TM (formerly called ST 246^®) and related products for 10 years following the initial commercial sale of the drug once SIGA earns $40.0 million in net profits from the sale of Arestvyr^TM and related products and remanded the issue of a remedy back to the trial court for reconsideration. As a result, there can be no assurance that the Delaware Court of Chancery will issue a remedy that provides us with a financial interest in Arestvyr^TM and related products or any remedy. Furthermore, there is significant uncertainty regarding the level and timing of sales of Arestvyr^TM and when and whether it will be approved by the U.S. Food and Drug Administration and corresponding health agencies around the world. Therefore, even if the Delaware Court of Chancery does award us a remedy that provides us monies related to sales or profit of Arestvyr^TM, we cannot predict with certainty if or when SIGA will begin recognizing profit on the sale thereof and there can be no assurance that any profits, if recognized, received by SIGA and paid to us will be significant. Significant additional non-clinical animal studies, human clinical trials, and manufacturing development work remain to be completed for all our products candidates, including Valortim, rBChE and SparVax^®. At this point, future government funding to support the development of Valortim^®, rBChE and SparVax^® is unlikely and remains uncertain. It is also uncertain whether any of our product candidates will be shown to be safe and effective and approved by regulatory authorities for use in humans. Forward-looking statements describe management’s current expectations regarding our future plans, strategies and objectives and are generally identifiable by use of the words “may,” “will,” “should,” “expect,” “anticipate,” “estimate,” “believe,” “intend,” “project,” “potential” or “plan” or the negative of these words or other variations on these words or comparable terminology. Such statements include, but are not limited to:

Forward-looking statements are based on assumptions that may be incorrect, and we cannot assure you that the projections included in the forward-looking statements will come to pass.

We have based the forward-looking statements included in this prospectus on information available to us on the date of this prospectus, and we assume no obligation to update any such forward-looking statements, other than as required by law. Although we undertake no obligation to revise or update any forward-looking statements, whether as a result of new information, future events or otherwise, you are advised to consult any additional disclosures that we may make directly to you or through reports that we, in the future, may file with the SEC, including Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K.

All forward-looking statements included herein are expressly qualified in their entirety by the cautionary statements contained or referred to above.

PROSPECTUS SUMMARY

This summary highlights certain information about us, this offering and selected information contained elsewhere in or incorporated by reference into this prospectus. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in the securities covered by this prospectus. For a more complete understanding of PharmAthene and this offering, we encourage you to read and consider carefully the more detailed information in this prospectus, including the information incorporated by reference in this prospectus and the information included in any free writing prospectus that we have authorized for use in connection with this offering, including the information referred to under the heading “Risk Factors” in this prospectus beginning on page S-4.

Our Company

We are a biodefense company engaged in the development and commercialization of next generation medical countermeasures against biological and chemical threats. Our current biodefense portfolio includes the following product candidates:

In May 2013, the Delaware Supreme Court affirmed a September 2011 ruling of the Delaware Court of Chancery that SIGA Technologies, Inc. ("SIGA") had breached certain contractual obligations to us. The matter is on remand to the Delaware Court of Chancery to determine a remedy in light of the Delaware Supreme Court’s decision. Previously the Delaware Court of Chancery had awarded us the right to receive 50% of all net profits (as defined in the court’s final judgment) related to the sale of SIGA, Arestvyr^TM (formerly known as ST-246^®) and related products for 10 years following initial commercial sale of the drug once SIGA earns $40.0 million in net profits from the sales of Arestvyr^TMand related products and a portion of our attorney’s fees and expert witness and other costs. While we believe there may be significant revenue potential under a potential damages award, there can be no assurance that the Delaware Court of Chancery will re-instate its prior remedy or order another remedy for us, that SIGA will not appeal any subsequent decision by the Delaware Court of Chancery, or that SIGA will not be successful in any subsequent appeal. Currently, because the Delaware Supreme Court remanded the issue of a remedy back to the Delaware Court of Chancery, we no longer have a financial interest in Arestvyr^TMand may never receive any proceeds from the product.

On April 4, 2014, we received notification from the U.S. Department of Health and Human Services (HHS), Biomedical Advanced Research and Development Authority (BARDA), advising us of its decision to de-scope the current SparVax^® anthrax vaccine contract through a partial termination for convenience. BARDA has subsequently provided guidance authorizing PharmAthene to complete six activities under the contract. All other activities were de-scoped, including the proposed Phase 2 clinical trial. PharmAthene has proposed a timeline for completing these contract activities up to and including the submission of its settlement proposal. The company expects these events to occur in the third or fourth quarter of 2014. We do not expect that we will receive additional significant funding from BARDA for the further development of SparVax^®. Therefore, unless we are able to secure additional funding for our SparVax^® development program, we anticipate that revenues for this program will be less in future periods than in prior years. We are continuing to explore different options for the future of the SparVax^® program.

Corporate Information

Our executive offices are located at One Park Place, Suite 450, Annapolis, Maryland 21401 and our telephone number is (410) 269-2600.  Our stock trades on the NYSE MKT under the symbol “PIP.”

We maintain a website at www.pharmathene.com. Our website and the information contained therein or connected thereto are not part of, or incorporated by reference into, this prospectus.

THE OFFERING

The number of shares of our common stock shown above to be outstanding immediately after this offering is based on 53,773,705 shares outstanding as of March 31, 2014 (excluding unvested restricted shares) and excludes:

RISK FACTORS

An investment in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks discussed below, together with the risks under the heading “Risk Factors” under Part I, Item 1A of our Annual Report on Form 10-K for the fiscal year ended December 31, 2013, filed with the SEC on March 11, 2014, and any subsequent Annual Report on Form 10-K or Quarterly Report on Form 10-Q, which are incorporated by reference into this prospectus, as well as the other information in this prospectus, the information and documents incorporated by reference herein and in any free writing prospectus that we have authorized for use in connection with this offering.If any of the identified risks actually occur, they could materially adversely affect our business, financial condition, operating results or prospects and the trading price of our securities, which could result in a loss of all or part of your investment. Additional risks and uncertainties that we do not presently know or that we currently deem immaterial may also impair our business, financial condition, operating results and prospects and the trading price of our securities.

Additional Risks Related to This Offering

Our management team will have broad discretion over the use of the net proceeds from this offering.

Our management will have broad discretion to direct the net proceeds from this offering for general corporate purposes. General corporate purposes may include working capital, research and development expenses, general and administrative expenses, capital expenditures and future acquisitions. See “Use of Proceeds.” Our management’s judgments may not result in positive returns on your investment and you will not have an opportunity, as part of your investment decision, to evaluate the economic, financial or other information upon which our management bases its decisions.

As an investor in this offering, you will experience immediate and substantial dilution and you may not be able to resell your shares at or above the offering price.

Since the price per share of our common stock being offered hereby is higher than the net tangible book value per share of our common stock, you will incur substantial dilution in the net tangible book value of the common stock you purchase in this offering. Furthermore, if the holders of outstanding options or warrants exercise those options or warrants at prices below the public offering price, you will incur further dilution. See “Dilution” for a more detailed discussion of the dilution you will incur if you purchase common stock in this offering, assuming you purchase the shares at $1.48, the last reported sale price of our common stock on NYSE MKT on May 15, 2014. The actual dilution you will incur may be higher or lower than the amount shown.

USE OF PROCEEDS

We currently intend to use the net proceeds, if any, from this offering for general corporate purposes, which may include working capital, research and development expenses, general and administrative expenses, and capital expenditures. We may also use a portion of the net proceeds to acquire or invest in businesses, products and technologies that are complementary to our own, although we have no present definitive commitments or agreements for any such transactions on the date of this prospectus. The amounts and timing of our actual expenditures for each purpose may vary significantly depending upon numerous factors, including the actual amount of proceeds we receive from this offering, the status of our research and product development efforts, regulatory approvals, competition and economic or other conditions. As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to us from this offering. Accordingly, our management will have broad discretion in the application of these proceeds. Pending application of such proceeds, we intend to temporarily invest the proceeds in short-term interest bearing, investment-grade marketable securities or money market obligations. We have a history of losses, which will continue for the foreseeable future. We do not expect that the proceeds from this offering, when added to our available cash, will be sufficient to last us through such time, if any, that we achieve positive cash flow. Accordingly, we anticipate that we will be required to raise additional funds through the sale of debt or equity securities or otherwise.

DILUTION

If you purchase our common stock in this offering, your interest will be diluted to the extent of the difference between the offering price per share and our pro forma net tangible book value per share of our common stock after this offering. Our net tangible book value as of March 31, 2014 was approximately $6.0 million, or $0.11 per share. Net tangible book value per share is determined by dividing our total tangible assets, less total liabilities, by the number of shares of our common stock outstanding as of March 31, 2014. Dilution in net tangible book value per share represents the difference between the amount per share paid by purchasers of shares in this offering and the net tangible book value per share of our common stock immediately after this offering.

After giving effect to the sale of our common stock in the aggregate amount of $15,000,000 in this offering at an assumed public offering price of $1.48 per share, the last reported sale price of our common stock on the NYSE MKT on May 15, 2014, and after deducting estimated offering commissions and expenses payable by us, our pro forma net tangible book value as of March 31, 2014 would have been approximately $20.4 million, or $0.32 per share. This represents an immediate increase in net tangible book value of $0.21 per share to existing stockholders and immediate dilution in net tangible book value of $1.16 per share to investors participating in this offering. The following table illustrates this dilution on a per share basis:

The above illustration of dilution per share to investors participating in this offering assumes for illustrative purposes that an aggregate of 10,135,135 shares of our common stock are sold at a price of $1.48 per share, the last reported sale price of our common stock on the NYSE MKT on May 15, 2014, for aggregate gross proceeds of $15,000,000. The shares sold in this offering, if any, will be sold from time to time at various prices. An increase of $0.50 per share in the price at which the shares are sold from the assumed offering price of $1.48 per share shown in the table above, assuming all of our common stock in the aggregate amount of $15,000,000 is sold at that price, would increase our pro forma net tangible book value per share after the offering to $1.98 per share and would increase the dilution in net tangible book value per share to new investors in this offering to $1.65 per share, after deducting commissions and estimated aggregate offering expenses payable by us. A decrease of $0.50 per share in the price at which the shares are sold from the assumed offering price of $1.48 per share shown in the table above, assuming all of our common stock in the aggregate amount of $15,000,000 is sold at that price, would decrease our pro forma net tangible book value per share after the offering to $0.98 per share and would decrease the dilution in net tangible book value per share to new investors in this offering to $0.68 per share, after deducting commissions and estimated aggregate offering expenses payable by us. This information is supplied for illustrative purposes only.

The number of shares of our common stock shown above to be outstanding immediately after this offering is based on 53,773,705 shares outstanding as of March 31, 2014 (excluding unvested restricted shares) and excludes:

The above illustration of dilution per share to investors participating in this offering assumes no exercise of options to purchase our common stock or warrants to purchase our common stock, that were outstanding as of March 31, 2014. The exercise of such options and warrants having an exercise price per share that is less than the offering price per share in this offering will increase dilution to investors in this offering. 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 additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

Our 2007 Plan provides for an annual automatic increase as of the first day of each fiscal year beginning in 2009 and continuing until 2015 equal to the lesser of (i) 1,100,000 shares, (ii) 2.5% of the outstanding shares of our common stock as of the end of our immediately preceding fiscal year, and (iii) any lesser number of shares determined by our Board of Directors; provided, however, that the aggregate number of shares available for issuance pursuant to such increases shall not exceed a total of 5,700,000 shares. The limit of 5,700,000 shares under the 2007 Plan was reached on January 1, 2014.

PRICE RANGE OF OUR COMMON STOCK

Our common stock trades on the NYSE MKT under the symbol “PIP.” The following table sets forth the range of high and low sales prices per share of our common stock on the NYSE MKT for each quarter during the past two fiscal years and the current quarter.

On May 15, 2014, the last reported sale price of our common stock on the NYSE MKT was $1.48 per share.

PLAN OF DISTRIBUTION

We have entered into a Controlled Equity Offering^SM sales agreement, as amended, with Cantor under which we may issue and sell shares of our common stock pursuant to this prospectus having an aggregate gross sales price of up to an additional $15,000,000 from time to time through Cantor, acting as agent. Amendment No. 1 to the sales agreement is filed as an exhibit to the Registration Statement on Form S-3 to which this prospectus relates and is incorporated by reference in this prospectus. In addition, the prospectus supplement, dated March 25, 2013, relating to the first $15,000,000 of shares of common stock pursuant to the sales agreement, as amended, will remain available for the sale of common stock by us until the earlier of the sale of all shares of common stock thereunder or July 26, 2014.

Upon delivery of a placement notice and subject to the terms and conditions of the sales agreement, as amended, Cantor may sell our common stock by any method permitted by law and deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act, including sales made directly on the NYSE MKT, on any other existing trading market for our common stock or to or through a market maker. In addition, pursuant to the terms and conditions of the sales agreement, as amended, and subject to our instructions, Cantor may also sell our common stock by any other method permitted by law, including in privately negotiated transactions. We may instruct Cantor 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 Cantor may suspend the offering of common stock upon notice and subject to other conditions.

We will pay Cantor commissions, in cash, for its services in acting as agent in the sale of our common stock. Cantor will be entitled to compensation at a fixed commission rate of 3.0% of the gross sales price per share sold. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. We estimate that the total expenses for the offering, excluding compensation and reimbursements payable to Cantor under the terms of the sales agreement, as amended, will be approximately $109,750.

Settlement for sales of common stock will occur on the third business day following the date on which any sales are made, or on some other date that is agreed upon by us and Cantor in connection with a particular transaction, in return for payment of the net proceeds to us. 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 may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

Cantor will use its commercially reasonable efforts, consistent with its sales and trading practices, to solicit offers to purchase the common stock shares under the terms and subject to the conditions set forth in the sales agreement, as amended. In connection with the sale of the common stock on our behalf, Cantor will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to Cantor against certain civil liabilities, including liabilities under the Securities Act.

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

Cantor 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, Cantor 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 and Cantor may distribute this prospectus electronically.

LEGAL MATTERS

Certain legal matters in connection with the securities offered hereby will be passed upon for us by Dentons US LLP of New York, New York. Cantor is being represented in connection with this offering by Reed Smith LLP, New York, New York.

EXPERTS

The consolidated financial statements of PharmAthene, Inc. appearing in PharmAthene, Inc.’s Annual Report (Form 10-K) for the year ended December 31, 2013, and the effectiveness of PharmAthene, Inc.’s internal control over financial reporting as of December 31, 2013, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3, of which this prospectus is a part, under the Securities Act, to register the shares of common stock offered by this prospectus. However, this prospectus does not contain all of the information contained in the registration statement and the exhibits and schedules to the registration statement. 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 intended to be comprehensive and are qualified in their entirety by reference to those filings. We encourage you to carefully read the registration statement and the exhibits and schedules to the registration statement.

As a public company, we are required to file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any of our materials on file with the SEC at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. Our filings are available to the public over the Internet at the SEC’s website at www.sec.gov. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” in this prospectus the information in other documents that we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus and may subsequently be updated and superseded as described below. We incorporate by reference in this prospectus the documents listed below and any future filings that we may make with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act prior to the termination of the offering under this prospectus.

We incorporate by reference the following documents we have filed, or may file, with the SEC:

To the extent that any information contained in any Current Report on Form 8-K, or any exhibit thereto, is furnished to, rather than filed with, the SEC, such information or exhibit is specifically not incorporated by reference in this prospectus.

We make available free of charge through our website at www.pharmathene.com our press releases and all of the documents that we are required to file electronically with the SEC, including all amendments thereto, as soon as reasonably practical after they are electronically filed with, or furnished to, the SEC. Our website also contains our Code of Ethics. The information on our website is not part of nor incorporated by reference into this prospectus.

In addition, we will provide, without charge to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request of such person, a copy of any or all of the documents incorporated by reference in this prospectus other than exhibits, unless such exhibits specifically are incorporated by reference into such documents or this prospectus. Requests for such documents should be addressed in writing or by telephone to: PharmAthene, Inc., One Park Place, Suite 450, Annapolis, Maryland 21401, (410) 269-2600, Attention: Corporate Secretary.

Any statement contained in this prospectus or in any document incorporated or deemed to be incorporated by reference in this prospectus will be deemed to have been modified or superseded to the extent that a statement contained in this prospectus or in any other document we subsequently file with the SEC that also is incorporated or deemed to be incorporated by reference in this prospectus modifies or supersedes the original statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to be a part of this prospectus.

You should rely only on the information provided in and incorporated by reference into 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 on the front cover of these documents.

2019.

settlement payments incurred in connection with any proceeding other than a derivative suit (and against certain expenses in connection with a derivative suit) and resulting from his or her service to the Company.

The foregoing description of the Indemnification Agreements does not purport to be complete and is qualified in its entirety by reference to the actual agreement, a form of which is attached as an exhibit to the Company’s Current Report on Form8-K, filed on January 27, 2009,2009.

See the Exhibit Index attached to this Registration Statement and which is incorporated herein by reference.

Item 16. Exhibits.

See the index to exhibits, which is incorporated herein by reference.

Item 17. Undertakings.

(a) The undersigned registrant hereby undertakes:

(1) toTo file, during theany period in which offers or sales are being made, a post-effective amendment to this registration statement:

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

Act;

(ii) toTo 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 not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the CommissionSEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percenta 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) toTo include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided,however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) doshall not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the CommissionSEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement;

statement.

(2) that,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 initialbona fide offering thereof; and

thereof.

(3) toTo 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.

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

(i)           (A)(a) 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

(B)II-2

(b) 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 thethat prospectus relates, and the offering of such securities at that time shall be deemed to be the initialbona 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.

(6)           that, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the 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 (§230.424 of this chapter);

(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)(c) 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.

(h)(d) 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 U.S. Securities and Exchange CommissionSEC 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 (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant 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 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 against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

(e) 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 in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

SIGNATURESII-3

EXHIBIT INDEX

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SIGNATURES

Pursuant to the requirements of the Securities Act, of 1933, as amended, the RegistrantAltimmune, Inc. 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 Statement on FormS-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Annapolis,Gaithersburg, State of Maryland, on May 23, 2014.the 4^th day of April, 2019.

POWER OF ATTORNEY

KNOW ALL MENPERSONS BY THESE PRESENTS, that each of the undersignedperson whose signature appears below constitutes and appoints Eric I. RichmanVipin K. Garg and Linda L. Chang,Will Brown, and each of them, as his or herattorneys-in-fact and agents, each with fullthe power of substitution, and resubstitution, for and in the name, place and stead of the undersigned,him or her in any and all capacities, to sign this Registration Statement, any and all amendments thereto (including post- effectivepost-effective amendments) to this Registration Statement or any Registration Statement for this offering that is to be effective upon the filing pursuant to Rule 462(b) under the Securities Act, as amended, and all post-effective amendments thereto,, and to file the same, with all exhibits thereto and all other documents in connection therewith, with the U.S. Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as the undersigned might or could do in person,SEC, hereby ratifying and confirming all that each of said attorney-in-factattorneys-in fact, or his substitute or 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 Registration Statement has been signed below by the following persons in the capacities indicated, on May 23, 2014.listed opposite their respective names.

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