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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

Commission File Number 0-15006

CELLDEX THERAPEUTICS, INC.
(Exact name of registrant as specified in its charter)

119 Fourth Avenue, Needham, Massachusetts 02494

(Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code:(781) 433-0771

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:None

         Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o    No ý

         Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o    No ý

         Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý    No o

         Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes o    No o

         Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this Chapter) is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ý

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

         Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes o    No ý

         The aggregate market value of the voting and non-votingregistrant's common stock held by non-affiliates as of June 30, 20082009 was $103,792,910 (excludes shares held by directors and executive officers).$100.8 million. Exclusion of shares held by any person should not be construed to indicate that such person possesses the power, direct or indirect, to direct or cause the actions of the management or policies of the registrant, or that such person is controlled by or under common control with the registrant.

         The number of shares of common stock outstanding at February 20, 200925, 2010 was 15,820,59331,711,124 shares.

DOCUMENTS INCORPORATED BY REFERENCE

         Portions of the definitive Proxy Statement for our 2010 Annual Meeting of Stockholders are incorporated by reference into Part III of this Report.

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CELLDEX THERAPEUTICS, INC.
ANNUAL REPORT ON FORM 10-K
YEAR ENDED DECEMBER 31, 2008
2009

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Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995:    This report on Form 10-K contains forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 under Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements include statements with respect to our beliefs, plans, objectives, goals, expectations, anticipations, assumptions, estimates, intentions and future performance, and involve known and unknown risks, uncertainties and other factors, which may be beyond our control, and which may cause our actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by such forward-looking statements. All statements other than statements of historical fact are statements that could be forward-looking statements. You can identify these forward-looking statements through our use of words such as "may," "will," "can," "anticipate," "assume," "should," "indicate," "would," "believe," "contemplate," "expect," "seek," "estimate," "continue," "plan," "point to," "project," "predict," "could," "intend," "target," "potential" and other similar words and expressions of the future.

        There are a number of important factors that could cause the actual results to differ materially from those expressed in any forward-looking statement made by us. These factors include, but are not limited to:

•

our ability to successfully complete product research and further development, including animal, preclinical and clinical studies, and commercialization of CDX-110, CDX-011, CDX-1307, CDX-1401, CDX-1135, and other products and the growth of the markets for those product candidates;



•

our ability to raise sufficient capital on terms acceptable to us, or at all;



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the cost, timing, scope and results of ongoing safety and efficacy trials of CDX-110, CDX-011, CDX-1307, CDX-1401, CDX-1135, and other preclinical and clinical testing;



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our ability to adapt our APC Targeting Technology™ to develop new, safe and effective vaccines against oncology and infectious disease indications;



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our ability to adapt our vectoring systems to develop new, safe and effective orally administered vaccines against disease causing agents;



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our ability to successfully complete product research and further development, including animal, preclinical and clinical studies, and commercialization of CDX-110, CDX-1307, Ty800, CDX-1135 (formerly TP10), and other products and the growth of the markets for those product candidates;



•

the cost, timing, scope and results of ongoing safety and efficacy trials of CDX-110, CDX-1307, Ty800, CDX-1135 (formerly TP10), and other preclinical and clinical testing;



•

the ability to negotiate strategic partnerships or other disposition transactions for our non-core programs, including CETi;programs;



•

our ability to manage multiple clinical trials for a variety of product candidates at different stages of development;



•

the strategies and business plans of our partners, such as Pfizer's plans for CDX-110, GlaxoSmithKline's plans with respect to Rotarix® and Vaccine Technologies' plans concerning the CholeraGarde® (Peru-15) and ETEC E. coli vaccines, which are not within our control, and our ability to maintain strong, mutually beneficial relationships with those partners;



•

our ability to successfully integrate our and CuraGen's business without causing delays in the research and development necessary to select drug development candidates and/or delays in clinical trials, and to operate the combined business efficiently;



•

our ability to develop technological capabilities and expand our focus to broader markets for vaccines;



•

the availability, cost, delivery and quality of clinical and commercial grade materials produced by our own manufacturing facility or supplied by contract manufacturers and partners;



•

the timing, cost and uncertainty of obtaining regulatory approvals for product candidates;



•

our ability to develop and commercialize products before competitors that are superior to the alternatives developed by such competitors;

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the validity of our patents and our ability to avoid intellectual property litigation, which can be costly and divert management time and attention; and



•

the factors listed under "Risk Factors" in this annual report on Form 10-K.

        All forward-looking statements are expressly qualified in their entirety by this cautionary notice. You are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date of this report or the date of the document incorporated by reference into this report. We have no obligation, and expressly disclaim any obligation, to update, revise or correct any of the forward-looking statements, whether as a result of new information, future events or otherwise. We have expressed our expectations, beliefs and projections in good faith and we believe they have a reasonable basis. However, we cannot assure you that our expectations, beliefs or projections will result or be achieved or accomplished.

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PART I

Item 1.    BUSINESS

A.    General

        As used herein, the terms "we," "us," "our," the "Company", or "Celldex" refer to Celldex Therapeutics, Inc., a Delaware corporation organized in 1983 (formerly known as AVANT Immunotherapeutics, Inc.) and its direct and indirect subsidiaries: Celldex Research Corporation ("Celldex Research"), and Celldex Therapeutics, Ltd. ("Celldex Ltd.") and Megan Health, Inc. ("Megan"). The Company'sOur principal activity since our inception has been research and product development conducted on our own behalf, as well as through joint development programs with several pharmaceutical companies and other collaborators. AVANT Immunotherapeutics, Inc. changed its name to Celldex Therapeutics, Inc. on October 1, 2008.

        Celldex isWe are an integrated biopharmaceutical company that applies itsour comprehensive Precision Targeted Immunotherapy Platform to generate a pipeline of candidates to treat cancer and other difficult-to-treat diseases. Celldex'sOur immunotherapy platform includes a complementary portfolio of monoclonal antibodies, antibody-targeted vaccines, antibody-drug conjugates and immunomodulators to create novel disease-specific drug candidates.

        Our strategy is to develop and demonstrate proof-of-concept for our product candidates before leveraging their value through partnerships or, in appropriate situations, continuing late stage development through commercialization ourselves. Demonstrating proof-of-concept for a product candidate generally involves bringing it through Phase 1 clinical trials and one or more Phase 2 clinical trials so that we are able to demonstrate, based on human trials, good safety data for the product candidate and some data indicating its effectiveness. We thus leverage the value of our technology portfolio through corporate, governmental and non-governmental partnerships. This approach allows us to maximize the overall value of our technology and product portfolio while best ensuring the expeditious development of each individual product.

        Our current collaborations encompassinclude the commercialization of an oral human rotavirus vaccine and the development of oncology and infectious disease vaccines. Our product candidates address large market opportunities for which we believe current therapies are inadequate or non-existent.

AVANT Merger between AVANT and Celldex:

        On March 7, 2008, we closed the merger (the "Merger") contemplated by the Agreement and Plan of Merger dated October 19, 2007 by and among Celldex (formerly AVANT Immunotherapeutics, Inc. ("AVANT"), Callisto Merger Corporation ("Merger Sub"), a wholly owned subsidiary of Celldex, and merged with Celldex Research (formerly known as Celldex Therapeutics, Inc.), a privately-held company, (the "Merger Agreement""AVANT Merger"). PursuantEffective October 1, 2008, we changed our name from AVANT Immunotherapeutics, Inc. to the terms of the Merger Agreement, Merger Sub merged with and into Celldex Research, with Celldex Research as the surviving company and a wholly-owned subsidiary of the Company. The total value of the transaction was approximately $75 million. Approximately 8.7 million shares were issued to the former Celldex Research shareholders in connection with the Merger. The Merger created a NASDAQ-listed, fully-integrated and diversified biopharmaceutical company with a deep pipeline of product candidates addressing high-value indications including oncology, infectious and inflammatory diseases. At the Merger, former Celldex and former AVANT shareholders owned 58% and 42% of the combined company on a fully diluted basis, respectively.Therapeutics, Inc.

        Our board of directors approved a 1-for-12 reverse stock split of the Company's common stock, which became effective on March 7, 2008. As a result of the reverse stock split, each twelve shares of common stock were combined and reclassified into one share of common stock and the total number of shares outstanding was reduced from approximately 180 million shares (including the shares issued to former Celldex Research stockholders in the Merger) to approximately 15 million shares.

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The AVANT Merger was accounted for using the purchase method of accounting and was treated as an acquisition by Celldex Research of Celldex (then AVANT), with Celldex Research being considered the accounting acquirer based on the application of criteria specified in Statement of Financial Accounting Standards "SFAS" No. 141,Business Combinations, ("SFAS 141"),AVANT even though Celldex (then AVANT)AVANT was the issuer of common stock and the surviving legal entity in the transaction. Under the purchase method of accounting, the deemed purchase price was allocated to AVANT's underlying tangible and identifiable intangible assets acquired and liabilities assumed based upon their respective fair values with any excess deemed purchase price allocated to goodwill. The valuation analysis conducted by the Company determined that the fair value of assets acquired and the fair value of liabilities assumed by Celldex Research exceeded the purchase price for AVANT, resulting in negative goodwill of approximately $6.0 million. In accordance with SFAS 141, the negative goodwill has been allocated to all of the acquired assets which were non-financial and non-current assets, including property and equipment, identifiable intangible assets, and in-process research and development. See Note 17 to the Company's consolidated financial statements for additional information.

Because Celldex Research was determined to be the acquirer for accounting purposes, the historical financial statements of Celldex Research became theour historical financial statementsas of the Company.closing of the AVANT Merger. Accordingly, theour financial statements of the Company prior to the AVANT Merger reflect the financial position, results of operations and cash flows of Celldex Research, which during the historical periods presented in the accompanying consolidated financial statements, was then majority-owned by Medarex, Inc. ("Medarex"). Following the AVANT Merger, the financial statements of the current period reflect the financial position, results of operation and cash flows of the Company.combined companies. The results of operations of AVANT are included in our results of operations beginning March 8, 2008.

Acquisition of CuraGen Corporation ("CuraGen")

        On October 1, 2009, CuraGen, then a publicly-traded company, merged with a wholly-owned subsidiary of Celldex (the "CuraGen Merger"). In connection with the CuraGen Merger, effective

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October 1, 2009, we (i) issued 15,722,713 shares of our common stock, or 0.2739 shares, in exchange for each share of outstanding CuraGen common stock, plus cash in lieu of fractional shares (the "CuraGen Exchange Ratio"), (ii) assumed all of the CuraGen stock options outstanding under the CuraGen 2007 Stock Plan (the "CuraGen 2007 Options"), and (iii) assumed the obligations of the $12.5 million in CuraGen 4% convertible subordinated debt due in February 2011 (the "CuraGen Debt"). The CuraGen 2007 Options are exercisable into 931,315 shares of our common stock after applying the CuraGen Exchange Ratio.

        In connection with the consummation of the CuraGen Merger, effective October 1, 2009, Celldex, CuraGen, and The Bank of New York Mellon (formerly the Bank of New York) (the "Trustee") amended the CuraGen Debt to provide that the CuraGen Debt shall be convertible into 353,563 shares of Celldex common stock at the rate of 28.27823 shares of Celldex common stock per $1,000 principal amount of notes, or $35.36 per share.

        Based on the closing price of our common stock on October 1, 2009 of $5.43, the fair value of the shares issued in the CuraGen Merger was $85.4 million. We have applied acquisition accounting as of October 1, 2009. Accordingly, the results of operations of the Company beginning March 8, 2008. Accordingly, except as otherwise discussed below, this report reflects the financial condition,CuraGen have been included in our results of operations and liquidity of the combined companies atbeginning October 1, 2009.

        On December 31, 20082009, we completed the merger of our CuraGen subsidiary with and historicallyinto Celldex pursuant to a short-form merger effected under Delaware law. As a result, the separate corporate existence of Celldex Research on a stand-alone basis forCuraGen has ceased and we have succeeded to all periods prior to March 8, 2008. The financial condition, resultsrights, privileges, powers and franchises of operations and liquidity of the Company as of the years ended December 31, 2008, 2007 and 2006 may not be indicative of the Company's future performance or reflect what the Company's financial conditions, results of operations and liquidity would have been had the Merger been consummated as of January 1, 2006 or had the Company operated as a separate, stand-alone entity during the periods presented.CuraGen.

        Celldex'sWe are a Delaware corporation organized in 1983. Our web site is located athttp://www.celldextherapeutics.com. On Celldex'sour web site, investors can obtain a copy of Celldex'sour annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and other reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act of 1934, as amended, as soon as reasonably practicable after Celldex fileswe file such material electronically with, or furnishes it to, the Securities and Exchange Commission.Commission ("SEC"). None of the information posted on our website is incorporated by reference into this Annual Report.

Research and Development Activities:Activities    Our products are derived from a broad set of complementary technologies (collectively known as our Precision Targeted Immunotherapy Platform) which have the ability to utilize the human immune system and enable the creation of preventative and therapeutic agents. We are using our Precision Targeted Immunotherapy Platform to develop vaccines, therapeutic antibodies and other targeted immunotherapeutics that prevent or treat cancer, autoimmune disorders and disease caused by infectious organisms, and treatment vaccines that modify undesirable activity by the body's own proteins or cells. A number of our immunotherapeutic and vaccine product candidates are in various stages of clinical trials. We expect that a large percentage of

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our research and development expenses will be incurred in support of our current and future clinical trial programs. Below is a table of our currently active programs:

CURRENT PROGRAMS AND PARTNERSHIPS

        We currently have one product on the market and six products in clinical development.        Our goal is to become a leading developer of innovative products that we call Precision Targeted Immunotherapeutics which are designed to address major unmet health care needs. Our success has depended and will continue to depend upon many factors, including our ability, and thatMost of our licenseesproducts are derived from a set of complementary technologies (collectively known as our Precision Targeted Immunotherapy Platform). This platform includes monoclonal antibodies, antibody-targeted vaccines, antibody-drug conjugates and collaborators,immunomodulators to successfullycreate novel disease-specific drugs. We are using our Precision Targeted Immunotherapy Platform to develop obtain regulatory approval fortargeted immunotherapies that prevent or treat specific forms of cancer, autoimmune disorders and commercialize our product candidates. To date, commercial sales have only been generated from Rotarix® and our former Megan poultry vaccines. We have had no commercial revenues from salesdisease caused by infectious organisms.

Table of our human therapeutic or other human vaccine products and we have had a history of operating losses. It is possibleContents

        The following table includes the programs that we may not be ablecurrently believe are material to successfully develop, obtain regulatory approval for or commercialize our product candidates, and we are subject to a number of risks that you should be aware of before investing in Celldex. These risks are described more fully in "Item 1A. Risk Factors."business:

        Using our expertise in immunology, we are building business franchises in major disease areas: oncology, inflammatory and infectious diseases. Each of our business franchises addresses large market opportunities for which current therapies are inadequate or non-existent. We have pursued some of these opportunities independently in a highly focused manner. In other cases, we have leveraged the financial support and development capabilities of corporate and public sector partners to bring our development projects to fruition. The research we have pursued over the past several years has matured into what we believe is an exciting portfolio of product candidates.

        Our success has depended and will continue to depend upon many factors, including our ability, and that of our licensees and collaborators, to successfully develop, obtain regulatory approval for and commercialize our product candidates. Commercial sales are currently only being generated from Rotarix®. We have had no commercial revenues from sales of our human therapeutic or other human vaccine products and we have had a history of operating losses. It is possible that we may not be able to successfully develop, obtain regulatory approval for or commercialize our product candidates, and we are subject to a number of risks that you should be aware of before investing in us. These risks are described more fully in "Item 1A. Risk Factors."

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B.    Development Strategy

Precision Targeted Immunotherapy Platform:

        We believe there is tremendous untapped potential in immunotherapy that can be exploited through the right combination of therapeutic agents. Our industry has traditionally taken biologics that mediate effective cancer regression in mice and expected similar results in humans. There are many explanations why this strategy often does not succeed, but the most important is that immunotherapy has difficulties when following standard drug development. The mechanism of action is complex, activity is generally not dependent on highest tolerated dose, and patient response is highly variable. Our new understanding of the immune system, cancer's effect on immune mediated mechanisms, and the impact of conventional therapies on the immune system provides a new rationale for combining therapies that may lead to significant clinical responses. The concept of Precision Targeted Immunotherapy is to exploit this knowledge and the availability of good products that may not be sufficiently effective to be commercialized as a monotherapy, but which we believe may be very effective in combination approaches. Our goal is to develop products that maximize the efficacy of immunotherapy regimens through combinations of therapeutic agents. This includes:

        TheTherapeutic Antibody Programs:    These programs are based on the well validated approach to using antibodies that target to cancer and other diseases directly, or through interfering with critical interactions between the patient and the disease. Our antibody programs include antibody-drug conjugates (ADCs) that are designed to deliver potent cytotoxic molecules to cancer cells, and

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traditional unmodified antibody approaches. Our current programs are based on fully human sequence antibodies to minimize patient reactivity against the drug. In addition, we have access through a Research and Commercialization Agreement with Medarex (now a subsidiary of Bristol-Myers Squibb) to the UltiMAb® Technology for generating fully human monoclonal antibodies. Under this agreement, we can exercise up to ten separate licenses to develop and commercialize therapeutic antibody products, either alone or through collaboration with our licensing partners.

        Our APC technology:Targeting Technology™:    This is a new class of vaccines based on our proprietary antibody-targeted vaccine technology that is used to generate an immune response against cancer or other diseases.

Our APC Targeting Technology™ uses human monoclonal antibodies or mAbs, linked to disease associated antigens to efficiently deliver the attached antigens to immune cells known as antigen presenting cells, or APCs. This technology has been designed to allow us to take advantage of many important characteristics of human monoclonal antibodies, including their long circulating half-life, well known safety profile, and standardized manufacturing procedures. We believe that our APC Targeting Technology™ provides significant manufacturing, regulatory and other practical advantages over patient specific and other immune-based treatments and can substantially reduce the dosage and cost currently required in conventional immunotherapies. Preclinical studies have demonstrated that APC Targeting Technology™ is more effective than conventional non-targeted vaccines. We have developed several proprietary monoclonal antibodies that can independently be developed to generate new product opportunities. We have initiatedOur CDX-1307 and CDX-1401 programs are in clinical development with the first APC technology product, called CDX-1307. In addition, CDX-1401 is completing its preclinical development and is expected to begin clinical testing in Phase 1/2 trials during 2009.

        Therapeutic Antibody Programs:technology.    These programs are based on the well validated approach to using antibodies that target to cancer and other diseases directly or through interfering with critical interactions between the patient and the disease. Celldex is in preclinical development for therapeutic human antibodies to molecules important in inflammation and cancer. In addition, Celldex has access through a Research and Commercialization Agreement with Medarex to the UltiMAb® Technology for

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generating fully human monoclonal antibodies. Under this agreement, Celldex can exercise up to ten separate licenses to develop and commercialize therapeutic antibody products, either alone or through collaboration with Celldex licensing partners.

        Immune System Modulators:    Immune system modulators include drugs that activate or suppress specific parts of the immune system, including suchsystem. Currently we are combining our APC technology product candidates with molecules known as Toll-Like Receptor (TLR) agonists that can activate patients' innate and adaptive immunity,immunity. We are also developing an immune cell growth factor called FMS-like tyrosine kinase 3 ligand (FLT3-L or CDX-301) designed to expand immune cells and stem cells. In addition, we are investigating the activity of a complement inhibitor (CDX-1135) that suppresses inflammatory reactions. These agents further support our Precision Targeted Immunotherapy Platform.

        Celldex'sOur strategy is to utilize our expertise to design and develop targeted immunotherapeutics that have significant and growing market potential; to establish governmental and corporate alliances to fund development; and to commercialize our products either through corporate partners or, in appropriate circumstances, through our own direct selling efforts. Our goal is to demonstrate clinical proof-of-concept for each product, and then seek partners to help see those products which we cannot develop ourselves through to commercialization. This approach allows us to maximize the overall value of our technology and product portfolios while best ensuring the expeditious development of each individual product. Implementation of this strategy is exemplified by our lead programs which are discussed in the following sections.

        Factors that may significantly harm our commercial success, and ultimately the market price of our common stock, include but are not limited to, announcements of technological innovations or new commercial products by our competitors, disclosure of unsuccessful results of clinical testing or regulatory proceedings and governmental approvals, adverse developments in patent or other proprietary rights, public concern about the safety of products developed by Celldexus and general economic and market conditions. See "Item 1A. Risk Factors."

C.    Cancer VaccineClinical Development Programs

        CDX-110:CDX-110

        Our lead clinical development program, CDX-110, is a peptide-based immunotherapy that targets the tumor specific molecule called EGFRvIII, a functional variant of the naturally expressed epidermal growth factor receptor ("EGFR"), a protein which has been well validated as a target for cancer

therapy. Unlike EGFR, EGFRvIII is not present in normal tissues, and has been shown to be a transforming oncogene that can directly contribute to the cancer cell growth.

EGFRvIII is commonly present in glioblastoma multiforme, or GBM, the most common and aggressive form of brain cancer, and has also been observed in various other cancers such as breast, ovarian, prostate, colorectal, and head & neck cancer. Our partner,

        In April 2008, we and Pfizer Inc. ("Pfizer"), entered into a License and weDevelopment Agreement (the "Pfizer Agreement") under which Pfizer was granted an exclusive worldwide license to CDX-110. The Pfizer Agreement also gives Pfizer exclusive rights to the use of EGFRvIII vaccines in other potential indications. Pfizer funds all development costs for these programs. We and Pfizer are currently pursuing the development of CDX-110 for GBM therapy and plan to expand the clinical development into other cancers through additional clinical studies. The Food and Drug Administration ("FDA") has granted orphan drug designation for CDX-110 for the treatment of EGFRvIII expressing GBM as well as fast track designation.

        Initial clinical development of EGFRvIII immunotherapy was led by collaborating investigators at the Brain Center at Duke Comprehensive Cancer Center in Durham, North Carolina and at M.D. Anderson Cancer Center in Houston, Texas. The results from the Phase 1 (VICTORI) and Phase 2a (ACTIVATE) studies, which enrolled 16 and 21 patients, respectively, have demonstrated a significant increase in the time to disease progression (greater than 113%) in the patients who were vaccinated, and also in overall survival rates (greater than 100%), both relative to appropriately matched historical controls. An extension of the Phase 2a program (ACT II) at the same two institutions has enrolled 23 additional GBM patients treated in combination with temozolomide (the current standard of care). Preliminary results from this study (ACT II) currently estimates median overall survival to be 33.123.6 months, although the median has not yet been reached. Thereached, while the survival of a matched historical control group was 14.3 months and a subgroup treated with temozolomide (TMZ) of 15.215.0 months with a p value = 0.0078.0.0237. Overall time to progression for CDX-110in the ACT II study was 16.615.2 months compared with 6.46.3 months for the historical control group.

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        In May 2007, weWe initiated a Phase 2b/3 randomized study (ACT III) of CDX-110 combined with standard of care, temozolomide, versus standard of care alone in patients with GBM. We have opened a total ofGBM in over 30 sites inthroughout the United States for the study. The FDA has granted orphan drug designation for CDX-110 for the treatment of EGFRvIII expressing GBM as well as fast track designation.

States. In December 2008, we announced an amendment to convert the ACT III study to a single-arm Phase 2 clinical trial in which all patients will receive CDX-110 in combination with temozolomide and we will continue to enroll to approximately 60 patients.temozolomide. The decision, which followsfollowed the recommendation of the Independent Data Monitoring Committee, was based on the observation that the majority of patients randomized to the control (standard of care) arm withdrew from this open-label study after being randomized to the control arm. Patients currently participating on the control arm of the study will bewere offered the option to receive treatment with CDX-110. Under this amendment, the ACT III study will provideprovided for a multi-center, non-randomized dataset for CDX-110 in patients with newly diagnosed GBM. These data will provide important additional information that can be used to better design the future development of CDX-110. Enrollment in ACT III is complete with a total of over 60 patients enrolled and we expect to present updated results during 2010.

CDX-011

        On April 16,CDX-011 (formerly CR011-vcMMAE) is an antibody-drug conjugate (ADC) that consists of a fully-human monoclonal antibody, CR011, linked to a potent cell-killing drug, monomethyl-auristatin E (MMAE). The CR011 antibody specifically targets glycoprotein NMB or (GPNMB) that is expressed in a variety of human cancers including breast cancer and melanoma. The ADC technology, comprised of MMAE and a stable linker system for attaching it to CR011, was licensed from Seattle Genetics, Inc. The ADC is designed to be stable in the bloodstream. Following intravenous administration, CDX-011 targets and binds to GPNMB, and upon internalization into the targeted cell, CDX-011 is designed to release MMAE from CR011 to produce a cell-killing effect. We acquired the rights to CDX-011 in connection with the CuraGen Merger.

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        Treatment of Breast Cancer:    In June 2008, an open-label, multi-center Phase 1/2 study was initiated of CDX-011 administered intravenously once every three weeks to patients with locally advanced or metastatic breast cancer who have received prior therapy (median of seven prior regimens). The study began with a bridging phase to confirm the Companymaximum tolerated dose ("MTD") and Pfizer enteredhas expanded into a License and Development Agreement (the "Pfizer Agreement") under which Pfizer was granted an exclusive worldwide license to a therapeutic cancer vaccine candidate, CDX-110, in Phase 2 developmentopen-label, multi-center study.

        The study confirmed the safety of CDX-011 at the pre-defined maximum dose level (1.88 mg/kg) in 6 patients. An additional 28 patients were enrolled as an expanded Phase 2 cohort (for a total of 34 treated patients at 1.88 mg/kg, the Phase 2 dose) to evaluate the progression-free survival ("PFS") rate at 12 weeks. As previously seen in melanoma patients, the 1.88 mg/kg dose was well tolerated in this patient population with the most common adverse events of rash, alopecia, and fatigue. The primary activity endpoint, which called for at least 5 of 25 (20%) patients in the Phase 2 study portion to be progression-free at twelve weeks, has been met. To date, 9 of 26 (35%) evaluable patients are without progression of disease at twelve weeks.

        In addition, at the Phase 2 dose level, 4 of 32 (13%) evaluable patients achieved confirmed or unconfirmed Partial Responses ("PR") while 15 of 25 (60%) evaluable patients with measurable disease experienced some reduction in tumor size. GPNMB expression was identified in 10 of 14 (71%) of analyzed tumor samples and treatment with CDX-011 was associated with improved outcomes in all activity parameters in patients whose tumors expressed GPNMB. Notably, in patients who received the Phase 2 dose and whose tumors expressed GPNMB, 2 of 7 (29%) had confirmed PR, 5 of 7 (71%) had decreases in tumor size, and all 7 achieved at least stable disease with duration from 17.3 to 26.9 weeks. The median PFS in all patients was 9.1 weeks, but in patients whose tumors expressed GPNMB, median PFS was 18.3 weeks, compared to median PFS of 5.9 weeks for patients whose tumors did not express GPNMB. In patients with triple negative disease, 5 of 7 (71%) analyzed samples expressed GPNMB, 7 of 9 (78%) evaluable patients had tumor shrinkage, and the median PFS for these patients was 17.9 weeks.

        We expect to initiate a randomized Phase 2b controlled study in patients with advanced breast cancer that express GPNMB in the second half of 2010.

        Treatment of Metastatic Melanoma Cancer:    In June 2006, a Phase 1/2 open-label, multi-center, dose escalation study was initiated to evaluate the safety, tolerability and pharmacokinetics of CDX-011 for patients with un-resectable Stage III or Stage IV melanoma who have failed no more than one prior line of cytotoxic therapy. During the Phase 1 portion of the study, doses of CDX-011 between 0.03 mg/kg to 2.63 mg/kg were evaluated and generally well tolerated, with rash and neutropenia emerging at higher doses. The MTD was determined to be 1.88 mg/kg administered intravenously (IV) once every three weeks.

        In June 2009, CuraGen announced results for the treatment of glioblastoma multiforme. The Pfizer Agreement also gives Pfizer exclusive rights to the use of EGFRvIII vaccines in other potential indications. Under the Pfizer Agreement, Pfizer made an upfront payment to the Company of $40 million and made a $10 million equity investment36 patients who were treated in the Company. Pfizer will fund all development costs for these programs.Phase 2 portion of the study. Of the patients enrolled, 94% had Stage IV disease of which two-thirds were classified as M1c, the poorest risk group. The Company is also eligiblestudy successfully met its primary activity endpoint, with 5 objective responses (1 unconfirmed) observed in 34 evaluable patients, and median duration of response of 5.3 months. The median overall PFS was 4.4 months. Tumor shrinkage was observed in 58% of patients, and 20 patients had best response of stable disease. Dermatologic adverse events consisting of rash, alopecia, and pruritus were the most common toxicities in this study. Other adverse events included fatigue, diarrhea, musculoskeletal pain, anorexia and nausea. Grade 3 or 4 neutropenia was observed in 5 patients. The absence of rash in the first cycle of treatment predicted a worse PFS. Additionally, in a subset of patients with tumor biopsies, high levels of tumor expression of GPNMB appeared to receive potential milestone payments exceeding $390 million forcorrelate with favorable outcome.

        Enrollment has been completed in the successful developmentPhase 1 portion of the melanoma trial to evaluate more frequent dosing schedules of CDX-011, including a weekly and commercializationa two out of CDX-110every three-week regimen, to explore if more frequent administration can provide additional activity in patients with metastatic

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melanoma. A dose of 1.0 mg/kg given once every week has been identified as the MTD in a weekly schedule, and additional EGFRvIII vaccine products, as well as royalties on any product sales. The Pfizer Agreement became effective after clearance undera dose of 1.5mg/kg was being explored in the Hart-Scott-Rodino Antitrust Improvements Acttwo out of 1976 (as amended) on May 19, 2008.three week schedule. Although median duration of follow-up was only 6 weeks, objective responses have thus far been observed in 3 of 11 evaluable patients treated with weekly CDX011 (1 confirmed) and 1 confirmed response in 8 evaluable patients treated with CDX-011 two out of every three weeks. We expect to present updated results during the first half of 2010.

        CDX-1307:CDX-1307    The Company's

        Our lead APC Targeting Technology™ product candidate, CDX-1307, is in development for the treatment of epithelial tumors such as colorectal, pancreatic, bladder, ovarian and breast cancers. CDX-1307 targets the beta chain of human chorionic gonadotropin, known as hCG-Beta, which is an antigen often found in epithelial tumors. The presence of hCG-Beta in these cancers correlates with a poor clinical outcome, suggesting that this molecule may contribute to tumor growth. Normal adult tissues have minimal expression of hCG-Beta; therefore, targeted immune responses are not expected to generate significant side effects.

        CelldexEnrollment is completingcomplete in our two Phase 1 studies of CDX-1307 at multiple centers that are designed to explore safety and dose/effect relationships via two administration routes—intradermal (ID), a traditional vaccine route that allows efficient access to local dermal dendritic cells and intravenous (IV), a novel systemic approach to vaccination that might target a much larger population of dendritic cells. In bothThe Phase 1 studies there are dose escalationsinvestigated the safety and immunogenicity of CDX-1307 alone and CDX-1307in combination with the adjuvantadjuvants, including GM-CSF (known to increase mannose receptor expression on dendritic cells). At the highest dose levels, additional immune system modulators (Toll-Like and Toll-Like Receptor Agonists,("TLR") agonists (poly-ICLC or TLR agonists) have been added to determine what effect they have in augmenting an immune response.Hiltonol™ and R848 or resiquimod). Patients with an assortment of different tumor types that are known to express hCG-Beta are being accruedwere enrolled with retrospective analysis for hCG-Beta expression. AAn escalating four dose regimen iswas utilized with the possibility of retreatment if patients demonstrate tumor regression or stable disease.

        Over Fifty (50)The Phase 1 studies enrolled over 80 patients with epithelial cancers have been treatedheavily pretreated, advanced-stage breast, colon, bladder and pancreatic cancer, with an average of 4.6 prior therapies across the treatment population. All patient cohorts demonstrated a favorable safety profile with no dose limiting toxicity to date. The combination of CDX-1307 with TLR agonists significantly enhanced immune responses against hCG-Beta, providing humoral responses in 88% of patients and cellular immune responses in 57% of patients analyzed to date. Immune responses occurred even in the Phase 1 clinical trials and more than half have evidencepresence of high circulating levels of hCG-Beta, expression by their tumor. The immunotherapy has been well tolerated with only minor adverse events observed (reddening atsuggesting that the injection site). Analysis of the initial cohorts with GM-CSF have revealed that severalCDX-1307 can overcome antigen tolerance in advanced and heavily pretreated cancers. Nine patients developed good humoral responses to

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hCG-Beta, and some have demonstrated enhancement of circulating hCG-Beta-specific CD8 T cells. Thus, we are encouraged that CDX-1307 is providing similar results as predicted in the pre-clinical studies. In addition, one patient with pancreatic cancer had a 26% overall reduction in tumor burden and two breast cancer patients were stable for sixstudies experienced disease stabilization from 2.3 months during treatment. The investigators atto 11.4 months following the Duke Comprehensive Cancer Center were awarded a two year $500,000 grant from the Avon Foundation and the National Cancer Institute to support Phase 1 work in breast cancer. The safetyinitiation of CDX-1307 vaccination. Two of these patients have received multiple courses of CDX-1307 and continue treatment with stable disease at 6.4 and 11.4 months. These data provide the basis for advancing CDX-1307 into a front-line patient population selected for hCG-Beta expressing cancers.

        We expect to initiate a randomized Phase 2b controlled study in combinationpatients with defined immune system modulators is now being evaluated with intent to enter Phase 2 clinical researchnewly diagnosed invasive bladder cancer in the second halfquarter of 2009.2010. Patient's whose bladder cancer expresses hCG-Beta are predicted to have more aggressive disease and shorter survival. In this study we plan to select only patients with confirmed hCG-Beta expression using a specific diagnostic assay.

        CDX-1401:CDX-1401

        CDX-1401 is a fusion protein consisting of a fully human monoclonal antibody with specificity for the dendritic cell receptor, DEC-205, linked to the NY-ESO-1 tumor antigen. In humans, NY-ESO-1 is one of the most immunogenic tumor antigens and has been detected in 20 - 30% of cancers, thus representing a broad opportunity. This product is intended to selectively deliver the NY-ESO-1 antigen to APCs for generating robust immune responses against cancer cells expressing NY-ESO-1. Unlike CDX-1307, which targets the mannose receptor

        We have entered into a License Agreement with the University of Southampton, UK, to develop human antibodies to CD27, a potentially important target for immunotherapy of various cancers. In pre-clinicalpreclinical models, antibodies to CD27 alone have been shown to mediate anti-tumor effects, and may be particularly effective in combination with other immunotherapies. CD27 is a critical molecule in the activation pathway of lymphocytes. It is downstream from CD40, and may provide a novel way to regulate the immune responses. Engaging CD27 with the appropriate monoclonal antibody has proven highly effective at promoting anti-cancer immunity in mouse models. We are currently evaluating new human monoclonal antibodies in pre-clinicalpreclinical models.

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        CDX-1135CDX-014

        CDX-014 (formerly TP10):CR014-vcMMAE) is a fully-human monoclonal ADC that targets TIM-1, an immunomudulatory protein that appears to down regulate immune response to tumors. The antibody, CDX-014, is linked to a potent chemotherapeutic, monomethyl auristatin E (MMAE), using Seattle Genetics' proprietary technology. The ADC is designed to be stable in the bloodstream, but to release MMAE upon internalization into TIM-1-expressing tumor cells, resulting in a targeted cell-killing effect. CDX-014 has shown potent activity in preclinical models of ovarian and renal cancer. We acquired the rights to CDX-014 in connection with the CuraGen Merger.

CDX-1189

        We have been developing immunotherapeutics that inhibit a part of the immune system called the complement system. The complement system is a series of proteins that are important initiators of the body's acute inflammatory response against disease, infection and injury. Excessive complement activation also plays a role in some persistent inflammatory conditions. Our lead compound, CDX-1135, a soluble form of naturally occurring Complement Receptor 1, has effectively shown to inhibit the activation of the complement cascade in animal models and in human clinical trials. We believe that regulating the complement system could have therapeutic and prophylactic applications in several acute and chronic conditions, including organ transplantation, multiple sclerosis, rheumatoid arthritis, age-related macular degeneration ("AMD"), atypical Hemolytic Uremic Syndrome and myasthenia gravis. We are currently defining the most appropriate clinical development path for CDX-1135 and are focusing on rare disease conditions of unregulated complement activation as potentially the fastest route to FDA approval.

        CDX-1189:    Celldex is developing therapeutic human antibodies to a signaling molecule known as CD89 or Fca receptor type I (FcaRI). CD89 is expressed by some white blood cells and leukemic cell lines, and has been shown to be important in controlling inflammation and tumor growth in animal models. Celldex hasWe have proprietary, fully human antibodies to CD89 in preclinical development. Depending upon the specific antibody used, anti-CD89 antibodies can either be activating and thus stimulate immune responses, or down-regulating and act as an anti-inflammatory agent.

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E.    Infectious Disease Development Programs

        CholeraGarde® Vaccine:    CholeraGarde® is designed to be a safe, effective single-dose, oral cholera vaccine. Our partner, the International Vaccine Institute ("IVI"), has received $21 million in funding from the Bill & Melinda Gates Foundation for a Cholera Vaccine Initiative ("CHOVI"), which includes conducting further clinical trials of CholeraGarde®. The IVI is presently conducting a Phase 2 clinical trial of CholeraGarde in Bangladesh, with plans to sponsor additional Phase 2 studies in India and Thailand beginning in the first half of 2009, followed by Phase 3 field studies.

        ETEC Vaccine:    In November 2007, we        We have entered into an agreementcollaborative partnership agreements with the Division of Microbiologypharmaceutical and Infectious Diseases of the NIAID, whereby NIAID is sponsoring a Phase 1 study of Celldex's investigational single-dose, oral vaccine designedother companies and organizations that provide financial and other resources, including capabilities in research, development, manufacturing, and sales and marketing, to offer combined protection against both enterotoxigenicEscherichia coli (ETEC) and cholera. In June 2008, NIAID initiated the Phase 1 trial of the ETEC vaccine candidate at Cincinnati Children's Hospital Medical Center.

        In January 2009, we entered into an Exclusive License and Development Agreement with Vaccine Technologies, Inc. ("VTI"). Under the license agreement, Celldex has granted a worldwide fee- and royalty-bearing exclusive license to VTI to development and commercialize Celldex's CholeraGarde® and ETEC vaccine programs. Financial terms of the agreement with VTI include an upfront license fee, milestone payments and royalties on net sales of licensed products during the term of the agreement.

        Ty800 Typhoid Fever Vaccine:    The Company has developed an oral vaccine to offer rapid, single-dose protection againstSalmonella typhi, the cause of typhoid fever. Ty800 is targeted for both the travelers' market and global health needs. In 2006, the National Institute of Allergy and Infectious Disease ("NIAID") of the National Institutes of Health ("NIH") initiated a Phase 1/2 in-patient dose-ranging clinical trial aimed at demonstrating the safety and immunogenicity of the Ty800 typhoid fever vaccine. NIAID funded the production of Ty800 vaccine for clinical testing and completed the Phase 1/2 trial at a NIH-funded clinical site in 2007. Results showed the single-dose, oral vaccine to be well tolerated and immunogenic, with over 90% of vaccinated subjects generating immune responses. We initiatedsupport our own sponsored Phase 2 trial of Ty800 in July 2007. Preliminary results reported in April 2008 from the study showed that the single-dose, oral vaccine was well tolerated and immunogenic, demonstrating that the desired immune response was achieved. Incidence of reactogenicity symptoms and adverse events post-vaccination were similar to placebo. Importantly, immunogenic response was dose-dependent. Positive immune response or seroconversion (prospectively defined as a 4-fold increase in anti-LPS titers over pre-dose level) rates were 65.5% (³⁶/55) and 80% (⁴⁴/55) in the low and high dose groups, respectively, and was significantly (p<0.001) higher than placebo.

        CDX-2401:    The Company is also using its APC Targeting Technology™ to develop vaccines against infectious disease. The lead program is CDX-2401, an APC-Targeting prophylactic vaccine, aimed at providing protection from infection with HIV, the virus known to cause AIDS. This program is in a Bill & Melinda Gates Foundation funded partnership with collaborators at Rockefeller University in New York City, who have shown in model systems that protective immunity can be induced with such a vaccine. Preclinical studies and manufacturing development are in progress and the Company, with its collaborators, plans to file an IND for Phase 1 clinical studies in the first half of 2009.

F.     Marketed Products

        Rotavirus Vaccine:    Rotavirus is a major cause of diarrhea and vomiting in infants and children. In 1997, we licensed our oral rotavirus strain to GlaxoSmithKline ("Glaxo"). All of the ongoing development for this program is being conducted and funded by Glaxo. Glaxo gained approval for its

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rotavirus vaccine, Rotarix®, in Mexico in July 2004, which represented the first in a series of worldwide approvals and commercial launches for the product. Glaxo subsequently launched Rotarix® in additional Latin American and Asian Pacific countries during 2005 - 2007. Additionally, Glaxo filed for market approval with the European regulatory authorities in late 2004, which triggered a $2 million milestone payment to the Company. In February 2006, the European Commission granted approval of Rotarix® in the European Union, which triggered a $4 million milestone payment from Glaxo. On April 3, 2008, Rotarix® received approval from the FDA for the prevention of rotavirus gastroenteritis in infants. FDA approval triggered a $1.5 million milestone payment from Glaxo, of which $750,000 was retained by the Company. We licensed-in the rotavirus strain in 1995 and owe a license fee of 30% to Cincinnati Children's Hospital Medical Center ("CCH") on net royalties received from Glaxo. In May 2005, the Company entered into an agreement whereby an affiliate of Paul Royalty Fund ("PRF") purchased an interest in the net royalties the Company will receive on worldwide sales of Rotarix® (see Note 10 of our consolidated financial statements). The market launch of Rotarix® by Glaxo in the U.S. market during the quarter ended September 30, 2008 resulted in a $10 million milestone payment to the Company from PRF, which the Company received on October 1, 2008. We have received a total of $60 million in milestone payments under the PRF agreement. No additional milestone payments are due from PRF under the agreement.

        In September 2006, we received notice from Glaxo that Glaxo would begin paying royalties on sales of Rotarix® vaccine at the lower of two royalty rates under their 1997 license agreement. Glaxo's decision to pay the lower royalty rate (which is 70% of the full rate) is based upon Glaxo's assertion that Rotarix® is not covered by the patents Glaxo licensed from the Company in Australia and certain European countries. If Glaxo's position stands, the royalties to which PRF is entitled will no longer be limited by a $27.5 million annual threshold, which the Company projected may have been reached in later years as sales of Rotarix® increased. Irrespective of Glaxo's position, we will still retain approximately 65% of the royalties on worldwide sales of Rotarix® once PRF receives 2.45 times the aggregate cash payments of $60 million it made to the Company, though the potential amount of such residual royalties will be lower if Glaxo's position stands.

Megan®Vac 1 and Megan®Egg Vaccines: On December 1, 2000, the Company acquired all of the outstanding capital stock of Megan. Megan has commercialized three veterinary vaccines; Argus™ SC, licensed by the United States Department of Agriculture ("USDA") in March 1998 and marketed by Intervet, Inc., and Megan®Vac 1 and Megan®Egg, licensed by the USDA in November 1998 and 2003, respectively, and marketed by Lohmann Animal Health International ("LAHI"). In January 2009, we sold the poultry vaccines business, consisting of Megan®Vac 1 and Megan®Egg, to LAHI for an upfront fee and potential milestone payments.

G.    Product Development and Licensing Agreements

1.     GlaxoSmithKline plc and Paul Royalty Fund II, L.P.

        In 1997, the Company entered into an agreement with Glaxo to collaborate on the development and commercialization of our oral rotavirus strain and Glaxo assumed responsibility for all subsequent clinical trials and all other development activities. We licensed-in the rotavirus strain that was used to develop Glaxo's Rotarix® rotavirus vaccine in 1995 and owe a license fee of 30% to CCH on net royalties received from Glaxo. We are obligated to maintain a license with CCH with respect to the Glaxo agreement. All licensing fees are included in research and development expense. The term of the Glaxo agreement is through the expiration of the last of the relevant patents covered by the agreement, although Glaxo may terminate the agreement upon 90 days prior written notice.

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        In May 2005, the Company entered into an agreement whereby an affiliate of PRF purchased an interest in the net royalties the Company will receive on worldwide sales of Rotarix®. Under the PRF agreement, the Company will retain 50% of future Glaxo milestone payments beginning on the effective date of the agreement with PRF, with 70% of the remaining balance payable to PRF and 30% of the remaining balance payable to CCH, respectively. The Company's retained interests in Rotarix® net royalties which were not sold to PRF are recorded as product royalty revenue and a corresponding amount that is payable to CCH is recorded as royalty expense, which is included in research and development expense.

        On April 3, 2008, Rotarix® received FDA market approval for the prevention of rotavirus gastroenteritis in infants, which triggered a $1.5 million milestone payment to the Company from Glaxo, $750,000 of which the Company retained under its agreement with PRF. In connection with the Company's purchase accounting for the Merger, the present value of the Company's retained amount, or $742,300, had been recorded as a current asset as of March 31, 2008. During the quarter ended June 30, 2008, the Company also recorded $225,000 in revenue and an offsetting amount in royalty expense for the payable due to CCH for its portion of the Glaxo milestone. The market launch of Rotarix® by Glaxo in the U.S. market during the quarter ended September 30, 2008 resulted in a $10 million milestone payment to the Company from PRF, which the Company received on October 1, 2008. As of March 31, 2008, the Company had recorded the expected present value of the $10 million milestone payment due from PRF of $9,053,200, the purchase accounting value assigned to the PRF milestone payment at the time of the Merger. During the quarter ended September 30, 2008, the Company recognized the balance of $946,800 as other income in the consolidated statement of operations. We have received $60 million in total milestone payments under the PRF agreement. No additional milestone payments are due from PRF under the agreement.

        Royalty rates on Rotarix® escalate from 7% to 10% based on net product sales in countries that have valid patent protection. These royalty rates are discounted by 30% for "non-patent" countries (primarily international markets). In September 2006, the Company received notice from Glaxo that Glaxo would begin paying royalties on sales of Rotarix® vaccine at the lower of the two royalty rates under their 1997 license agreement. Glaxo's decision to pay the lower royalty rate (which is 70% of the full rate) is based upon Glaxo's assertion that Rotarix® is not covered by the patents Glaxo licensed from the Company in Australia and certain European countries. If Glaxo's position stands, the royalties to which PRF is entitled will no longer be limited by a $27.5 million annual threshold, which the Company projected may have been reached in later years as sales of Rotarix® increased. Irrespective of Glaxo's position, the Company will still retain approximately 65% of the royalties on worldwide sales of Rotarix® once PRF receives 2.45 times the aggregate cash payments of $60 million it made to Celldex, though the potential amount of such residual royalties will be lower if Glaxo's position stands.

2.     GlaxoSmithKline plc and Corixa Corporation ("Corixa")

        On December 21, 2005, Corixa, a wholly-owned subsidiary of Glaxo, and Celldex Ltd. (formerly Lorantis Limited), entered into a termination agreement of their collaboration of CDX-2101, or HepVax, for the development of a therapeutic vaccine for Hepatitis B (the "Termination Agreement"). Under the terms of the Termination Agreement, Glaxo paid the Company the sum of approximately $1,632,000. In addition, and subject to the terms and conditions of the Termination Agreement, Glaxo granted to the Company a worldwide, fully paid up, royalty-free, perpetual, nonexclusive license under the Corixa Patent Rights, Corixa Know-How Rights and Corixa Licensed Technology (each as defined in the Termination Agreement): (a) to use RC-529SE in products being developed and/or commercialized by Celldex Ltd or its Permitted Sublicensees in the Lorantis Field; and (b) to make or have made RC-529SE using RC-529 adjuvant for the limited use permitted by the license granted to reformulate Corixa's proprietary adjuvant.

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3.     Pfizer Inc.

        Pfizer License and Development Agreement:    On April 16, 2008, the Company and Pfizer entered into a License and Development Agreement (the "Pfizer Agreement") under which Pfizer was granted an exclusive worldwide license to a therapeutic cancer vaccine candidate, CDX-110, in Phase 2 development for the treatment of glioblastoma multiforme. The Pfizer Agreement also gives Pfizer exclusive rights to the use of EGFRvIII vaccines in other potential indications. Under the Pfizer Agreement, Pfizer made an upfront payment to the Company of $40 million and made a $10 million equity investment in the Company. Pfizer will fund all development costs for these programs. The Company is also eligible to receive potential milestone payments exceeding $390 million for the successful development and commercialization of CDX-110 and additional EGFRvIII vaccine products, as well as royalties on any product sales. The Pfizer Agreement became effective after clearance under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (as amended) on May 19, 2008.

        On May 27, 2008, the Company received $10 million from Pfizer in exchange for 781,250 shares of the Company's common stock having a fair value of $10,867,188, or $13.91 per share, on that date. The $867,188 over the amount received from Pfizer was recorded as a reduction to deferred revenue of the $40 million upfront payment received from Pfizer on June 18, 2008.

        The Company has applied the provisions of Emerging Issues Task Force (EITF) Issue No. 00-21 ("EITF 00-21"), Accounting for Revenue Arrangements with Multiple Deliverables, and determined that its performance obligations under this collaboration should be accounted for as a single unit of accounting. The Company's deliverables under this collaboration primarily include an exclusive license to its CDX-110 product candidate and its EGFRvIII technologies, research and development services as required under the collaboration and participation in the joint clinical development committee. The Company has estimated that its performance period under the collaboration will be 9.5 years based on an assessment of the period over which the Company will have met its performance obligations under the collaboration. Revenue, including research and development reimbursements, is being recognized on a straight-line basis over this period using the Contingency Adjusted Performance Model ("CAPM"). The $40,000,000 up-front payment was recorded as deferred revenue and this amount, less the $867,188 in excess fair value for the Company's common stock discussed above, is being amortized over the 9.5-year performance period at a rate of $1,029,810 per quarter.

        The agreement also provides for reimbursement by Pfizer of all costs incurred by the Company in connection with the collaboration since the effective date. The Company invoices Pfizer monthly for its reimbursable costs and records the invoiced amount as deferred revenue. These deferred revenue amounts are amortized to revenue over the expected 9.5-year performance period on a straight-line basis using the CAPM model.

        In connection with the initial deliverables under the Pfizer Agreement as discussed further in Note 11, the Company has paid a sublicense fee of $2,365,174 to each of two research universities, Duke University ("Duke") and Thomas Jefferson University ("TJU"), and paid TJU an additional license fee of $500,000. In October 2008, the Company paid an additional sublicense fee to TJU of $1,634,826. These payments were recorded as deferred costs in the "Other Assets" line item in the consolidated balance sheet and are being amortized over the 9.5-year performance period at a rate of $180,663 per quarter.

        Pfizer Animal Health Agreement:    The Company entered into a licensing agreement in December 2000 with Pfizer's Animal Health Division whereby Pfizer has licensed Megan's technology for the development of animal health and food safety vaccines. Under the agreement, the Company may receive additional milestone payments of up to $3 million based upon attainment of specified milestones. The Company may receive royalty payments on eventual product sales. The term of this agreement is through the expiration of the last of the patents covered by the agreement. The Company has no obligation to incur any research and development costs in connection with this agreement.

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        As of June 1, 2006, the Company entered into a Collaborative Research and Development Agreement with Pfizer aimed at the discovery and development of vaccines to protect animals. In 2007, further funded work at the Company on the joint research program was terminated by Pfizer after the Company provided two of four deliverables to Pfizer.

4.     Rockefeller University ("Rockefeller")

        The Company is developing a vaccine, CDX-2401, aimed at providing protection from infection with HIV, the virus known to cause AIDS. This program is in a Bill & Melinda Gates Foundation funded partnership with collaborators at Rockefeller and the Aaron Diamond AIDS Research Center, who have shown in model systems that protective immunity can be induced with such a vaccine. Preclinical studies and manufacturing development are in progress and payments to the Company are made on a time and materials basis.

5.     Vaccine Technologies, Inc. ("VTI")

        In January 2009, we entered into an Exclusive License and Development Agreement with VTI. Under the license agreement, Celldex has granted a worldwide fee- and royalty-bearing exclusive license to VTI to development and commercialize Celldex's CholeraGarde® and ETEC vaccine programs. Financial terms of the agreement with VTI include an upfront license fee, milestone payments and royalties on net sales of licensed products during the term of the agreement.

We depend on our collaborativethese relationships and may enter into more of them in the future. Some of the above referenced agreements give our collaboratorpartners have substantial responsibility to commercialize a product and to make decisions about the amount and timing of resources that are devoted to developing and commercializing a product. As a result, we do not have complete control over how resources are used toward some of our products.

        In addition, someSome of theseour partnership agreements relate to products in the early stages of research and development. Others require Celldexus and our collaboratorcollaborators to jointly decide on the feasibility of developing a particular product using our technologies. In either case, these agreements may terminate without benefit to us if the underlying products are not fully developed. If we fail to meet our obligations under these agreements, they could terminate and we might need to enter into relationships with other collaborators and to spend additional time, money, and other valuable resources in the process.

        Moreover, weWe cannot predict whether our collaborators will continue their development efforts or, if they do, whether their efforts will achieve success. Many of our collaborators face the same kinds of risks and uncertainties in their business that we face. A delay or setback to a collaborator will, at a minimum, delay the commercialization of any affected products, and may ultimately prevent it. Moreover, any collaborator could breach its agreement with us or otherwise not use best efforts to promote our products. A collaborator may choose to pursue alternative technologies or products that compete with our technologies or products. In either case, if a collaborator failed to successfully develop one of our products, we would need to find another collaborator. Our ability to do so would depend upon our legal right to do so at the time and whether the product remained commercially viable.

H.    GlaxoSmithKline plc ("Glaxo") and Paul Royalty Fund II, L.P. ("PRF")

        Rotavirus is a major cause of diarrhea and vomiting in infants and children. In 1997, we licensed our oral rotavirus strain to Glaxo and Glaxo assumed responsibility for all subsequent clinical trials and all other development activities. Glaxo gained approval for its rotavirus vaccine, Rotarix®, in Mexico in July 2004, which represented the first in a series of worldwide approvals and commercial launches for the product leading up to the approval in Europe in 2006 and in the U.S. in 2008. We licensed-in our

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rotavirus strain in 1995 and owe a license fee of 30% to Cincinnati Children's Hospital Medical Center ("CCH") on net royalties received from Glaxo. We are obligated to maintain a license with CCH with respect to the Glaxo agreement. The term of the Glaxo agreement is through the expiration of the last of the relevant patents covered by the agreement, although Glaxo may terminate the agreement upon 90 days prior written notice.

        In May 2005, we entered into an agreement whereby an affiliate of PRF purchased an interest in the milestone payments and net royalties that we will receive on the development and worldwide sales of Rotarix®. We have received a total of $60 million in milestone payments under the PRF agreement. No additional milestone payments are due from PRF under the agreement.

        Royalty rates on Rotarix® escalate from 7% to 10% based on net product sales in countries that have valid patent protection. These royalty rates are discounted by 30% for "non-patent" countries (primarily international markets). In September 2006, we received notice from Glaxo that Glaxo would begin paying royalties on sales of Rotarix® vaccine at the lower of the two royalty rates under their 1997 license agreement. Glaxo's decision to pay the lower royalty rate (which is 70% of the full rate) is based upon Glaxo's assertion that Rotarix® is not covered by the patents Glaxo licensed from us in Australia and certain European countries. We are currently evaluating the basis for Glaxo's action and our potential remedies. If Glaxo's position stands, the royalties to which PRF is entitled will no longer be limited by a $27.5 million annual threshold, which we projected may have been reached in later years as sales of Rotarix® increased. Irrespective of Glaxo's position, we will still retain approximately 65% of the royalties on worldwide sales of Rotarix® once PRF receives 2.45 times the aggregate cash payments of $60 million it made to us, though the potential amount of such residual royalties will be lower if Glaxo's position stands.

Pfizer Inc.

        Pfizer License and Development Agreement:    In April 2008, we and Pfizer entered into the Pfizer Agreement under which Pfizer was granted an exclusive worldwide license to a therapeutic cancer vaccine candidate, CDX-110, in Phase 2 development for the treatment of glioblastoma multiforme. The Pfizer Agreement also gives Pfizer exclusive rights to the use of EGFRvIII vaccines in other potential indications. Under the Pfizer Agreement, Pfizer made an upfront payment to us of $40 million and made a $10 million equity investment in us. Pfizer will fund all development costs for these programs. We are also eligible to receive potential milestone payments exceeding $390 million for the successful development and commercialization of CDX-110 and additional EGFRvIII vaccine products, as well as royalties on any product sales. The Pfizer Agreement became effective after clearance under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (as amended) on May 19, 2008. In connection with the Pfizer Agreement, we paid a total of $6.9 million in sublicense fees to Duke University and Thomas Jefferson University.

        Pfizer Animal Health Agreement:    We entered into a licensing agreement in December 2000 with Pfizer's Animal Health Division whereby Pfizer has licensed our technology for the development of animal health and food safety vaccines. Under the agreement, we may receive additional milestone payments of up to $3 million based upon attainment of specified milestones. We may receive royalty payments on eventual product sales. The term of this agreement is through the expiration of the last of the patents covered by the agreement. We have no obligation to incur any research and development costs in connection with this agreement.

Rockefeller University ("Rockefeller")

        We are providing research and development support to Rockefeller on the development of their vaccine, DCVax-001, which we refer to as CDX-2401, aimed at providing protection from infection with HIV, the virus known to cause AIDS. Rockefeller's program is in a Bill & Melinda Gates Foundation

Research Collaboration and Licensing Agreements

        Celldex hasWe have entered into licensing agreements with several universities and research organizations. Under the terms of these agreements, we have received licenses or options to license technology, specified patents or patent applications.

Table Our licensing and development collaboration agreements generally provide for royalty payments equal to specified percentages of Contentsproduct sales, annual license maintenance fees and continuing patent prosecution costs. In addition, we have committed to make potential future milestone payments to third parties of up to approximately $116 million as part of our various collaborations including licensing and development programs. Payments under these agreements generally become due and payable only upon achievement of certain developmental, regulatory and/or commercial milestones.

1.     Medarex, Inc., a subsidiary of Bristol-Myers Squibb ("Medarex")

        The CompanyWe and Medarex, a former related party, have entered into the following agreements, each of which was approved by a majority of its independent directors who did not have an interest in the transaction. These agreements include:

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An Assignment and License Agreement, as amended, ("Assignment and License Agreement") that provides for the assignment of certain patent and other intellectual property rights and a license to certain Medarex technologytechnology; and a



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A Research and Commercialization Agreement, whichas amended, ("Research and Commercialization Agreement") that provides the Companyus with certain rights to obtain exclusive commercial licenses to proprietary monoclonal antibodies raised against certain antigens. Under these agreements with Medarex, Celldex may be obligated to pay license fees, milestone payments and royalties relating to the development and regulatory approval of certain of its technologies.

        Under the terms of the Assignment and License Agreement and Research and Commercialization Agreement, with Medarex, Celldex willwe may be required to pay Medarex license feesmilestone and royalty payments to obtain commercial licenses for antibodies arising from research licenses granted by Medarex. Celldex will also be required to pay Medarex milestone payments with respect to the development of any products containing such licensed antibodies. These fees and milestones may total up to $7 to $10 million per licensed antibody if a product containing such licensed antibody receives approval from the FDA and/or equivalent foreign agencies. None

Table of Celldex's product candidates currently under development trigger such milestone payments. In general, potential milestone payments for Celldex's antibody product candidates may or may not be triggered and may vary in size depending on a number of variables, almost all of which are currently uncertain. Typically, the events that trigger these payments per product candidate include:Contents

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submission of investigational new drug application(s) or foreign equivalents;



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commencement of Phase 1, Phase 2 and/or Phase 3 clinical trials or foreign equivalents;



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submission of biologic license application(s) or foreign equivalents; and



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receipt of marketing approval(s) to sell products in a particular country or region.

        In addition, Celldex will be requiredOctober 2007, we and Medarex entered into a settlement and mutual release agreement which settled disputed amounts we owed Medarex. We issued to pay royaltiesMedarex 351,692 shares of our common stock equal in value to $3.0 million, based on any salesthe per share price of products containing licensed antibodies. The royalties will be payable$8.64 set on a country-by-country and product-by-product basis until the date which issecond trading day prior to the later of: (i) the expirationclosing date of the last-to-expire of theAVANT Merger and exchanged releases. At December 31, 2008, we owed Medarex patents covering the productan additional $3.0 million related to a Master Services Agreement, which we paid Medarex in such country or (ii) the tenth anniversary of the first commercial sale of a product in such country. Celldex will also be responsible for the payment of any royalties, license fees and milestone and other payments due to third parties if Celldex licenses any additional technology in order to commercialize such products.

        To date, Celldex has not made any royalty payments on sales of any products and believes it is at least a number of years away from selling any products that would require Celldex to make any such royalty payments. Whether Celldex will be obligated to make milestone or royalty payments in the future is subject to the success of Celldex's product development efforts and, accordingly, is inherently uncertain.October 2009.

2.     Rockefeller University ("Rockefeller")

        OnIn November 1, 2005, the Companywe and Rockefeller entered into a license agreement for the exclusive worldwide rights to human DEC-205 receptor, with the right to sublicense the technology. The license grant is exclusive except that Rockefeller may use and permit other nonprofit organizations to use the human DEC-205 receptor patent rights for educational and research purposes. In addition,We may be required to pay milestone and royalty payments to Rockefeller with respect to development and commercialization of the Company acknowledges that Rockefeller has granted Howard Hughes Medical Institute ("HHMI") a paid-up, nonexclusive, irrevocable license to use the patent rights, biological materials, and technical information for HHMI's research purposes, but with no right to sublicense. The Companyhuman DEC-205 receptor. We may also be required to pay royalties on any product sales. The royalties will be payable on a country-by-country and licensed product-by-licensed product basis until the date which is the later of (i) the expiration of

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the last to expire of the patents covering the licensed product in such country or (ii) ten years following the first commercial sale of a licensed product in such country.

        The Company may be required to pay license fees and milestone payments to Rockefeller with respect to development of the human DEC-205 receptor. These fees and milestones may total up to $2 million to $4 million per product candidate that receives approval from the FDA and equivalent foreign agencies.

3.     Duke University Brain Tumor Cancer Center ("Duke")

        OnIn September 1, 2006, the Companywe and Duke University Brain Tumor Cancer Center of Duke University ("Duke") entered into a license agreement that gave the Companyus access and reference to the clinical data generated by Duke and its collaborators in order for the Companyus to generate itsour own filing with the FDA relating to itsthe CDX-110 product.

        In exchange for referencing all the Duke data, the Company paid Duke a one-time upfront payment of $175,000 and issued to Duke 100,000 shares of the Company's common stock, which the Company recorded in 2006 as a licensing expense in research and development. The estimated aggregate fair value of the common shares issued was $330,000.

        The Company We may be required to pay license feesmilestone and milestoneroyalty payments to Duke with respect to development and commercialization of the CDX-110 product. These fees and milestones may total up to $1.2 million if CDX-110 receives approval from the FDA and equivalent foreign agencies. The Company may also be required to pay royalties upon approval of CDX-110. The royalties will be payable on a country-by-country and licensed product-by-licensed product basis until the date of the expiration of the last to expire of the patents covering the licensed product in such country.

In connection with the Pfizer Agreement, discussed in Note 10, the Companywe determined that $2,365,174$2.4 million was payable to Duke as a sublicense fee. As agreed byprovided for under the Duke at the Company's option,license, we paid 50% of this amount was paid to Duke in the form of 81,512 shares of our common stock in October 2008.

4.     Ludwig Institute for Cancer Research

        On October 20, 2006, the Company and Ludwig Institute for Cancer Research ("Ludwig")

        In October 2006, we and Ludwig entered into an agreement for the nonexclusive rights to six cancer tumor targets for use in combination with the Company'sour APC Targeting Technology. The term of the agreement is for ten years. As consideration for the nonexclusive license, the Company agreed to pay an annual license fee of $7,500 and $2,500 for each full-length antigen and partial-length antigen, respectively, until such antigens enter a randomized Phase 1 clinical trial.

        As additional consideration for the nonexclusive license, the CompanyWe may be required to pay license feesmilestone and milestoneroyalty payments to Ludwig for the usewith respect to development and commercialization of the cancer targets in combination withtechnology licensed from Ludwig.

Alteris Therapeutics, Inc. ("Alteris")

        In October 2005, we completed the Company's technology. The fees and milestonesacquisition of the assets of Alteris, including the EGFRvIII molecule that we licensed to Pfizer under the Pfizer Agreement. We may total up to $1.5 million to $2.5 million on a product candidate that receives approval from the FDA and equivalent foreign agencies. The Company may also be required to pay royaltiesAlteris up to $5.0 million upon obtaining the first approval for commercial sale of anya product candidate. The royalties will be payable on a country-by-country and licensed product-by-licensed product basis until the date of the expiration of the last to expire of the patents covering the licensed product in such country.containing EGFRvIII, including CDX-110.

5.     Thomas Jefferson University ("TJU")

        In February 2003, as part of its acquisition of the EGFR VIII technology from Alteris Therapeutics, Inc., the Companywe entered into three exclusive license agreements with Thomas Jefferson University ("TJU"). Under the license agreements, TJU has granted a worldwide fee-and royalty-bearing exclusive license.TJU. Under these licenses, the Company willwe may be obligatedrequired to pay milestone and royalty payments to TJU milestone payments which may total upwith respect to $3 million for the first licensed product developed during the term of

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the license agreements, an annual license fee of $45,000, patentdevelopment and other expenses associated with licenses, as well as royalties on net sales of licensed products during the termcommercialization of the license agreements. The Company also issued 100,000 shares of its common stock totechnology licensed from TJU. In the event that TJU provides notice of default and the default is not cured within 60 days of such notice, TJU may terminate the license agreements. In connection with the Pfizer Agreement, the Companywe amended itsour licenses with TJU to add additional sublicensing rights and made a $500,000 one-time license paymentpaid $4.5 million in sublicense fees to TJU in June 2008.

        As discussed in Note 10, the Company paid a sublicense fee of $2,365,174 to TJU during the quarter ended September 30, 2008 and paid an additional sublicense fee of $1,634,826 to TJU in October 2008.

6.     Select Vaccines Limited3M Company

        In February 2007, the Company entered into a research and development partnership with Select Vaccines Limited ("Select Vaccines"), a public Australian biotechnology company, focused on the use of Select Vaccines' virus-like particles ("VLPs") as a platform technology for the development of viral vaccines. Under the terms of the agreement, the Company made an upfront equity investment of $735,000 in Select Vaccines and agreed to fund influenza vaccine research and development for two years, as well as provide payments to Select Vaccines for the achievement of specific preclinical and clinical development milestones. On November 1, 2007, the Company notified Select Vaccines that, effective December 31, 2007, the Company was exercising its rights to terminate its Collaboration and License Agreement with Select Vaccines for strategic reasons. In AugustJune 2008, the Company sold its equity investment in Select Vaccine shares and recorded net proceeds of $250,882.

7.     3M Company

        On June 11, 2008, the Companywe and 3M Company entered into a license agreement for the exclusive worldwide rights to access 3M Company's proprietary Immune Response Modifier, Resiquimod™, (and additional Toll-Like Receptor 7/8 agonists ("TLRs"TLR")) for clinical study with Celldex'sour proprietary APC Targeting Technology, for use as vaccine adjuvants, with the right to sublicense the technology.

        The Company paid 3M Company a one-time upfront license fee which was charged to research and development expense in the quarter ended June 30, 2008. The Company We may be

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required to pay annual license feesmilestone and milestoneroyalty payments to 3M Company with respect to development of Resiquimod™. The Company may also be required to pay royalties upon approval of any product candidate. The royalties will be payable on a country-by-country and licensed product-by-licensed product basis until the datecommercialization of the expiration of the last to expire of the patents covering thetechnology licensed product in such country.from 3M Company.

8.     University of Southampton

        In November 2008, the Company entered into an Exclusive Patent and Know-How License Agreement with the University of Southampton, UK ("Southampton")

        In November 2008, we entered into a license agreement with Southampton to develop human antibodies towards CD27, a potentially important target for immunotherapy of various cancers. CD27 is a critical molecule in the activation pathway of lymphocytes, is downstream from CD40, and may provide a novel way to regulate the immune responses. In pre-clinicalpreclinical models, antibodies to CD27 have been shown to mediate anti-tumor effects alone, and may be particularly effective in combination with the Company'sour other immunotherapies.

        The Company paid Southampton a one-time upfront license fee which was charged to research and development expense in the quarter ended December 31, 2008. The Company We may be required to pay annual license feesmilestone and milestoneroyalty payments to Southampton with respect to development and commercialization of CD27.the technology licensed from Southampton.

TableAmgen Inc. ("Amgen")

        In March 2009, we entered into a license agreement with Amgen to expand our Precision Targeted Immunotherapy Platform by acquiring exclusive rights to CDX-301 and CD40 ligand (CD40L). CDX-301 and CD40L are immune modulating molecules that increase the numbers and activity of Contents

The Companyimmune cells that control immune responses. We may also be required to pay royalties upon approvalmilestone and royalty payments to Amgen with respect to development and commercialization of this technology licensed from Amgen.

Amgen Fremont (formerly Abgenix)

        In connection with the CuraGen Merger, we assumed the license agreement between CuraGen and Amgen Fremont (successor in-interest to Abgenix) to develop fully-human monoclonal antibody therapeutics. In May 2009, an amendment to the license agreement ("Amgen Amendment") was entered into related to CuraGen's exclusive rights to develop and commercialize CDX-011 and 11 other licensed antigens. Under the Amgen Amendment, CuraGen and Amgen Fremont agreed to modify the terms of their existing cross-license of antigens whereby the amended license would be fully paid-up and royalty-free (except for any product candidate. The royalties willpotentially required payments by CuraGen to the original licensor of CDX-011).

Seattle Genetics, Inc. ("Seattle Genetics")

        In connection with the CuraGen Merger, we assumed the license agreement between CuraGen and Seattle Genetics whereby CuraGen acquired the rights to proprietary antibody-drug conjugate ("ADC") technology for use with its their proprietary antibodies for the potential treatment of cancer. We may be payable on a country-by-countryrequired to pay milestone and licensed product-by-licensed product basis until the dateroyalty payments to Seattle Genetics with respect to development and commercialization of the expiration of the last to expire of the patents covering the licensed product in such country.

        We depend on our collaborative relationships and may enter into more of them in the future. Some of the above referenced agreements give our collaborator substantial responsibility to make decisions about the amount and timing of resources that are devoted to developing a product. As a result, we do not have complete control over how resources are used toward some of our products.

        Some of these agreements relate to products in the early stages of research and development and may require Celldex and our collaborator to jointly decide on the feasibility of developing a particular product using our technologies. In either case, these agreements may terminate without benefit to us if the underlying products are not fully developed. Moreover, once specific products are chosen for development, the agreements relating to them may require Celldex to meet specified milestones, to invest money and other resources in the development process or to negotiate additional licenses and other agreements, which may not be possible or advantageous. If we fail to meet our obligations under these agreements, they could terminate and we might need to enter into relationships with other collaborators and to spend additional time, money, and other valuable resources in the process.

        Moreover, we cannot predict whether our collaborators will continue their development efforts or, if they do, whether their efforts will achieve success. Many of our collaborators face the same kinds of risks and uncertainties in their business that we face. A delay or setback to a collaborator will, at a minimum, delay the commercialization of any affected products, and may ultimately prevent it. Moreover, any collaborator could breach its agreement with us or otherwise not use best efforts to promote our products. A collaborator may choose to pursue alternative technologies or products that compete with our technologies or products. In either case, if a collaborator failed to successfully develop one of our products, we would need to find another collaborator. Our ability to do so would depend upon our legal right to do so at the time and whether the product remained commercially viable.ADC technology.

I.     Competition

        The biotechnology and pharmaceutical industries are intensely competitive and subject to rapid and significant technological change. Many of the products that Celldex iswe are attempting to develop and commercialize will be competing with existing therapies. In addition, a number of companies are pursuing the development of pharmaceuticals that target the same diseases and conditions that Celldex iswe are targeting. Celldex facesWe face competition from pharmaceutical and biotechnology companies both in the United States and abroad. Celldex'sOur competitors may utilize discovery technologies and techniques or partner with collaborators in order to develop products more rapidly or successfully than Celldexus or itsour collaborators are able to do. Many of Celldex'sour competitors, particularly large pharmaceutical companies, have substantially greater financial, technical and human resources than Celldex does.we do. In addition, academic institutions,

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government agencies and other public and private organizations conducting research may seek patent protection with respect to potentially competitive products or technologies and may establish exclusive collaborative or licensing relationships with Celldex'sour competitors.

Table        We face intense competition in our development activities. We face competition from many companies in the United States and abroad, including a number of Contents

        Severallarge pharmaceutical companies, firms specialized in the development and biotechnology companies are actively engaged inproduction of vaccines, adjuvants and vaccine and immunotherapeutic delivery systems and major universities and research and development in areas related to therapeutic vaccines, includinginstitutions. These competitors include Alexion, Anadys, Antigenics, Baxter, BioSante, Crucell, Dendreon, Eli Lilly, Emergent, Genitope, GlaxoSmithKline, Idera, Intercell, Sanofi-Aventis,Immunogen, Maxygen, Merck, NeoPharm, Northwest Biotherapeutics, Novavax, Pfizer, Roche, Genitope, Northwest Biotherapeutics, Vical, Anadys, Idera,Sanofi-Aventis, Seattle Genetics, and Cell Genesys. Celldex isVical. We are aware that Genitope, Northwest Biotherapeutics and Dendreon areis in late stage clinical trials for therapeutic vaccines for the treatment of lymphoma, GBM, melanoma and prostate cancer respectively, which may compete with CDX-1307 CDX-110 and CDX-1401. In addition, companies such as ImClone, Inc.Eli Lilly with its approved product Erbitux™ for the treatment of colorectal cancer, and Genentech, Inc.Roche with its product Herceptin® for the treatment of metastatic breast cancer, have already commercialized antibody-based products that may compete with CDX-1307, CDX-1401 and CDX-110. Various other companies are developing or commercializing products in areas that Celldex haswe have targeted for product development. Some of these products use therapeutic approaches that may compete directly with Celldex'sour product candidates. Many of these companies and institutions, either alone or together with their partners, have substantially greater financial resources and larger research and development staffs than Celldex does.we do. These companies may succeed in obtaining approvals from the Food and Drug Administration ("FDA")FDA and foreign regulatory authorities for their products sooner than Celldex doeswe do for itsour products.

        Celldex isWe are aware of a number of competitive products currently available in the marketplace or under development that are used for the prevention and treatment of the diseases that Celldex haswe have targeted for product development. Various companies are currently marketing or developing biopharmaceutical products that may compete with Celldex'sour product candidates that target colorectal cancer. Product candidates Celldexwe may develop are also subject to competition in the treatment of colorectal cancer from a number of products already approved and on the market, including the following chemotherapy products: AstraZeneca PLC's Tomudex®, Hoffman-LaRoche's Xeloda® (capecitabine), Immunex Corporation's Leucovorin® calcium, ImClone Systems' Erbitux™, Pfizer, Inc.'s Camptosar® (irinotecan) and Aduracil® (5-FU), Sanofi-Synthelabo Group's Eloxatin™ (oxaliplatin), Genentech's anti-VEGF antibody, Avastin™, GlaxoSmithKline's Eniluracil™, and Titan Pharmaceuticals' CeaVac™, in the treatment of patients with advanced-stage colorectal cancer. In addition, Celldex iswe are aware that other companies such as Cell Genesys and Dendreon may be developing additional cancer vaccines that could potentially compete with other Celldexof our product candidates. CelldexWe may also face competition from Medarex and Bristol-Myers Squibb, which are developing a therapeutic vaccine for the treatment of melanoma using Medarex's MDX-010 product candidate. CelldexWe also facesface competition from a number of companies working in the fields of anti-angiogenesis and specific active immunotherapy for the treatment of solid tumor cancers. Celldex expectsWe expect that competition among specific active immunotherapy and anti-angiogenesis products approved for sale will be based on various factors, including product efficacy, safety, reliability, availability, price and patent position.

        CelldexWe are aware of specific companies that are developing antibody drug conjugates (ADCs) for use in the treatment of cancer. Trastuzumab-DM1 (T-DM1) is a first-in-class HER2 antibody drug conjugate comprised of Genentech's (a Member of the Roche Group) trastuzumab antibody linked to ImmunoGen's cell-killing agent, DM1. T-DM1 combines anti-HER2 activity and targeted intracellular delivery of the potent anti-microtubule agent, DM1 (a maytansine derivative). A Phase 3 clinical trial evaluating T-DM1 for second-line HER2-positive metastatic breast cancer is planned and may be competitive with our developmental program in the breast cancer indication. Other ADCs are in development by our collaborator of the MMAE technology, Seattle Genetics, using monomethylaurastatin derivatives as the cell-killing agent in hematologic cancers and other cancers.

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Marketed products that are used in the treatment of melanoma include dacarbazine, temozolamide, and interleukin-2. In addition, several other pharmaceutical and biotechnology companies are engaged in research and development for the treatment of melanoma. Many more products are on the market or in development for the treatment of metastatic breast cancer. How CDX-011 will compete with these other commercial and development stage products in metastatic melanoma and breast cancer is not clear at this time.

        We also facesface competition from pharmaceutical and biotechnology companies, academic institutions, government agencies and private research organizations in recruiting and retaining highly qualified scientific personnel and consultants and in the development and acquisition of technologies. Moreover, technology controlled by third parties that may be advantageous to Celldex'sour business may be acquired or licensed by Celldex'sour competitors, thereby preventing us from obtaining technology on commercially reasonable terms, if at all. CelldexWe will also compete for the services of third parties that may have already developed or acquired internal biotechnology capabilities or made commercial arrangements with other biopharmaceutical companies to target the diseases on which Celldex haswe have focused both in the U.S. and outside of the U.S.

        Our competitive position will also depend upon our ability to attract and retain qualified personnel, obtain patent protection or otherwise develop proprietary products or processes and secure sufficient capital resources for the often lengthy period between technological conception and

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commercial sales. We will require substantial capital resources to complete development of some or all of our products, obtain the necessary regulatory approvals and successfully manufacture and market our products. In order to secure capital resources, we anticipate having to sell additional capital stock, which would dilute existing stockholders. We may also attempt to obtain funds through research grants and agreements with commercial collaborators. However, these types of fundings are uncertain because they are at the discretion of the organizations and companies that control the funds. As a result, we may not receive any funds from grants or collaborations. Alternatively, we may borrow funds from commercial lenders, likely at high interest rates, which would increase the risk of any investment in Celldex.us.

J.     Manufacturing

        We have no experience in volumelarge scale manufacturing and we have relied upon collaborators or contractors to manufacture some of our proposed products for both clinical and commercial purposes to date. We have established our own manufacturing facility in Fall River, Massachusetts, to produce antibodies, vaccines and other products that we may develop at scale for clinical trials. In order for us to establish a commercial manufacturing facility, we will require substantial additional funds and will be required to hire and retain significant additional personnel and comply with the extensive cGMP regulations of the FDA applicable to such facility. The commercial manufacturing facility would also need to be licensed for the production of antibodies, vaccines and other products by the FDA. We intend to establish manufacturing arrangements with manufacturers that comply with the FDA's requirements and other regulatory standards, although there can be no assurance that we will be able to do so.

        While we believe that there is currently sufficient capacity worldwide for the production of our potential products by our collaborators or through contract manufacturers, establishing long-term relationships with contract manufacturers and securing multiple sources for the necessary quantities of clinical and commercial materials required can be a challenge. Qualifying the initial source of clinical and ultimately commercial material is a time consuming and expensive process due to the highly regulated nature of the pharmaceutical/biotech industry. These costs are hopefully mitigated in the economies of scale realized in commercial manufacture and product sale. The key difficulty in qualifying more than one source for each product is the duplicated time and expense in doing so without the potential to mitigate these costs if the secondary source is never utilized.

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        In connection with the Pfizer Agreement, the manufacture of CDX-110 is the responsibility of Pfizer. To date, we have been arranging withutilized contract manufacturers for the manufacture of clinical trial supplies of CDX-110, CDX-1307CDX-011 and CDX-1135. Manufacture of the rotavirus vaccine is the responsibility of Glaxo, which has received from us a world-wide exclusive license to commercialize this vaccine.

        Two The two clinical lots of CDX-1307 have been manufactured and released for clinical studies by Medarex. This material is being used in Celldex's currentour completed Phase 1 clinical trials of CDX-1307.CDX-1307 were manufactured by contract manufacturers. In 2009, Celldex expects towe completed the manufacture of additional quantities of CDX-1307 in itsour Fall River facility to meet futureplanned Phase 2 clinical material requirements. The Company is currently manufacturingWe have also manufactured in our Fall River facility CDX-1401 clinical materials for our Phase 1/2 clinical trial currently enrolling and CDX-2401 clinical materials for a Rockefeller-sponsored Phase 1 clinical trial expected to begin in the secondfirst half of 2009.

        We contracted with Lonza Biologics plc for process development and scale-up of CDX-1135 for clinical trials and plan to manufacture CDX-1135 clinical materials in our Fall River facility in 2009. The Walter Reed Army Institute of Research ("WRAIR") has manufactured our bacterial vaccines under collaborative agreements with us. LAHI has manufactured the Megan®Vac 1 and Megan®Egg poultry vaccines.2010.

        The manufacturing processes for our other vaccine and immunotherapeutic delivery systems and vaccines utilize known technologies. We believe that the products we currently have under development can be scaled up to permit manufacture in commercial quantities. However, there can be no assurance that we will not encounter difficulties in scaling up the manufacturing processes.

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        Use of third party manufacturers limits our control over and ability to monitor the manufacturing process. As a result, we may not be able to detect a variety of problems that may arise and may face additional costs in the process of interfacing with and monitoring the progress of our contract manufacturers. If third party manufacturers fail to meet our manufacturing needs in an acceptable manner, we would face delays and additional costs while we develop internal manufacturing capabilities or find alternative third party manufacturers. It may not be possible to have multiple third party manufacturers ready to supply us with needed material at all or without incurring significant costs.

K.    Marketing

        Under the terms of existing and future collaborativepartnership agreements, we rely and expect to continue to rely on the efforts of our collaborators, including Glaxo, Pfizer, VTI, and TopoTarget/Spectrum for the sale and marketing of our products. We have agreements with, among others, Glaxo, Pfizer, Biolipox (formerly Inflazyme and AdProTech) and VTI for the development and commercialization of some of our products. The relevant aspects of these relationships have been previously discussed under the heading "G. Product Development and Licensing Agreements." There can be no assurance that our collaborators will develop and market vaccine products incorporating our technologies, or, if marketed, that such efforts will be successful. The failure of our collaborators to successfully market products would harm our business.

        We have retained, and in the future intend to retain, marketing rights to some of our product candidates, including vaccine and immunotherapeutic delivery systems and vaccine candidates, in selected geographic areas and for specified indications. We intend to seek marketing and distribution agreements and/or co-promotion agreements for the distribution of our products in these geographic areas and for these indications. We believe that these arrangements could enable us to generate greater financial return than might be obtained from early stage licensing and collaboration agreements. We have no marketing and sales staff and limited experience relating to marketing and distribution of commercial products, including vaccines. If we determine in the future to engage in direct marketing of our products, we will be required to recruit an experienced marketing group, develop a supporting distribution capability and incur significant additional expenditures. There can be no assurance that we will be able to establish a successful marketing force. We may choose or find it necessary to enter into strategic partnerships on uncertain, but potentially unfavorable, terms to sell, market and distribute our products. Any delay in the marketing or distribution of our products, whether it results from problems with internal capabilities or with a collaborative relationship, could harm the value of an investment in Celldex.us.

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L.    Patents, Licenses and Proprietary Rights

        Celldex's policyIn general, our intellectual property strategy is to protect our technology by filing patent applications and obtaining patent rights covering our own technology, both in the United States and in foreign countries.countries that we consider important to our business. In addition, we have acquired and will seek to acquire as needed or desired, exclusive rights of others through assignment or license to complement our portfolio of patent rights. We also rely on trade secrets, unpatented know-how and technological expertise and innovation to develop and maintain our competitive position.

        Patents:Patents

        The successful development and marketing of products by Celldexus will depend in part on our ability to create and maintain intellectual property, including patent rights. We have established a proprietary patent position in the areas of complement inhibitor technology, cholesterol regulation technology, vaccine technologies, and preservation technologies, and we are the owner or exclusive licensee to proprietary patent positions in the areas of numerous patentsvaccine technologies, antibody technologies and pending applications around the world.complement inhibitor technology. Although we continue to pursue patent protection for our products, no assurance can be given that any pending application will issue as a patent, that any issued patent will have a scope that will be of commercial benefit, or that we will be able to successfully enforce our patent position against infringers. CelldexWe routinely reviews its

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review our patent portfolio and adjusts its strategies for prosecution and maintenance of individual cases according to a number of factors including program priorities, stage of development, and patent term.

        Celldex ownsWe own or licenseslicense rights under more than 500400 granted patents and national and regional patent applications around the world covering inventions relating to our business. Through Celldex's acquisition ofThe key patents owned by us or licensed to us that we consider important to our business include the assets of Alteris Therapeutics, Inc., Celldex has certain exclusive rights under nine issued nationalfollowing (the indicated and estimated patent expiry dates do not include any possible Patent Term Extensions or regional patents and three pending national patent applications relating toSupplementary Protection Certificates, if these may be secured in due course):

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Patents for the technology used in CDX-110. One of the pending patent applications (in Japan) is currently under appeal. ExpirationCDX-110 have expiration dates for the key issued patents range from 2009 tothrough 2014 in the United States and from 2010 to 2015 in the United Kingdom, Germany and France (not including any possibleFrance. A pending patent term extensions or Supplementary Protection Certificates, if these are obtainedapplication in due course).

        In the area of APC targeting, through Celldex's agreements with Medarex and Rockefeller, CelldexJapan is the owner or exclusive licensee of more than 20 issued patents and more than 70 pending national and regionalcurrently under appeal. We also have rights under patent applications worldwide. Through Celldex's agreement witharound the Ludwig Institute, Celldex has an optionworld relating to obtain certainuses of CDX-110 which are currently pending. If issued and maintained to full term in a form which covers commercial rightsuse of CDX-110, the latter filings could potentially provide additional patent protection for the relevant use in connection with Celldex's APC targeting technology under more than 100 national and regional patents andthe relevant territories to 2026.



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Our patent portfolio for CDX-011 includes pending patent applications worldwide,in the US, Europe and Japan. If issued and maintained to full term in due course, these would have estimated patent expiry dates in 2025. In addition, patent rights relating to NY-ESO-1the toxin and various other tumor antigens. Through Celldex's acquisition of Lorantis Limited (now Celldex Therapeutics Ltd.), Celldex obtained,conjugation technology used in the area of Hepatitis B vaccination, certain exclusive rights under seven issuedCDX-011 have been licensed from Seattle Genetics.



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US patents and more than 40 pending national and regional patent applications worldwide and, in the area of Notch signaling modulation, control of 10 issued patents and more than 20 pending national and regional patent applications worldwide. Celldex also has non-exclusive rights under more than 30 national and regional patents and pending patent applications worldwide relatingfor the technology used in CDX-1307 have current or estimated expiration dates (subject to issue in the adjuvant formulation currently used with CDX-2101. Through Celldex's agreement with 3M, Celldex has certain exclusive rights under more than 100 issued patents and more than 50case of pending patent applications relatingapplications) that range from 2021 to 3M's Toll-Like Receptor (TLR 7/8) agonist technology, for use with Celldex's APT targeting technology, as vaccine adjuvants. Through Celldex's agreement with the University of Southampton, Celldex has certain exclusive rights under an2024.



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We have a pending international patent application relating to modulation of CD27 activity.

        In the area of complement inhibitor technology weused in CDX-1401 which, if issued in the main designated territories and maintained to full term in due course, would have rightsestimated patent expiry dates in 2028.



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Patents for the technology used in CDX-301 have current expiration dates that range from 2016 in the major European territories to 51 patents and patent applications worldwide with2020 in the key patents in this area expiring in 2013 and 2016. In the area of cholesterol regulation, we have rights to 35 patents and patent applications worldwide with the key patents in this area expiring in 2016 and 2019. In the area of rotavirus vaccines, we have rights to 20 patents and patent applications worldwide, with the key patents in this area expiring in 2011 and 2012. In the area of cholera and typhoid vaccines, we have rights to 112 patents and patent applications worldwide with the key patents in this area expiring between 2013 and 2016.

US.        In the area of complement inhibitors, we are co-owner with The Johns Hopkins University and Brigham & Women's Hospital, whose rights Celldex have exclusively licensed, of patents and applications covering inventions relating to soluble complement receptor type I ("sCR1"). These rights are based in part on the work of Dr. Douglas Fearon and include U.S. and foreign patents which claim nucleic acid sequences encoding CR1, sCR1 and active fragments; purification methods; and therapeutic uses of sCR1. We also own a number of other issued patents and patent applications relating to modified sCR1 molecules ("sCR1-sLe^x") and their uses.



        We also have an exclusive license to 19 issued U.S. and foreign patents directed to a rotavirus strain that has been developed by Glaxo into a commercial rotavirus vaccine.

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We have 26 issued patents and nine additionallicensed pending patent applications in the U.S.US, Europe and selected foreign countriesJapan relating to control of cholesteryl ester transfer protein (CETP) activity through vaccination.

the technology used in CDX-1127. If issued and maintained to full term in due course, these would have estimated patent expiry dates in 2027. Further filings are also under preparation.

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        In December 2000, we acquired Megan

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Our patent portfolio for CDX-014 includes pending patent applications in the US, Europe and by this acquisition obtained exclusive rightsJapan. If issued and maintained to vaccine technology patents and applications based on the work of Dr. Roy Curtiss III. Thesefull term in due course, these would have estimated patent rights complemented and expanded the patent rights acquired by Celldexexpiry dates in an earlier merger with Virus Research Institute, Inc., which had licensed in exclusive patent rights in this technological area from Harvard University and Massachusetts General Hospital, based on the work of Dr. John Mekalanos. In connection with our acquisition of Megan, we entered into a licensing agreement with Pfizer whereby Pfizer has licensed Megan's technology2024.



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Patents for the developmenttechnology used in CDX-1135 have expiration dates that range from 2013 to 2016.



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Our US patent and worldwide pending patent applications for the technology used in CDX-1189 have current or estimated expiration dates (subject to issue in the case of animal healthpending applications) in 2022.



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Patents for the technology used in the cholera and food safety vaccines.

        In January 2003, Celldex completed licensingtyphoid vaccines expire between 2013 and acquisition agreements2016. Our patent portfolio for ETEC includes pending patent applications around the world which, gave us ownership or exclusive rightsif issued and maintained to full term in certain defined fieldsdue course, would have estimated patent expiry dates in 2028.



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Licensed patents for our rotavirus strain that we licensed to a portfolio of patentsGlaxo have expiration dates in 2011 and applications filed by Universal Preservation Technologies, Inc. and Elan Drug Delivery Ltd. (now Innovata plc). This portfolio affords Celldex exclusive rights in a particular technology of foam preservation of biomolecules and cells, especially living cells useful as vaccines. This technology should be especially useful in Celldex's vaccine programs to produce vaccine dosage forms that are thermostable.

2012.

        There can be no assurance that patent applications owned by or licensed to Celldexus will result in granted patents or that, if granted, the resultant patents will afford protection against competitors with similar technology. It is also possible that third parties may obtain patents or other proprietary rights that may be necessary or useful to Celldex.us. In cases where third parties are first to invent a particular product or technology, it is possible that those parties will obtain patents that will be sufficiently broad to prevent us from using important technology or from further developing or commercializing important vaccine and immunotherapeutic systems and vaccine candidates. If licenses from third parties are necessary but cannot be obtained, commercialization of the covered products might be delayed or prevented. Even if these licenses can be obtained, they would probably require us to pay ongoing royalties and other costs, which could be substantial.

        Although a patent has a statutory presumption of validity in the United States, the issuance of a patent is not conclusive as to validity or as to the enforceable scope of the patent claims. The validity or enforceability of a patent after its issuance by the Patent and Trademark Office can be challenged in litigation. As a business that uses a substantial amount of intellectual property, we face a heightened risk of intellectual property litigation. If the outcome of the litigation is adverse to the owner of the patent, third parties may then be able to use the invention covered by the patent without authorization or payment. There can be no assurance that our issued patents or any patents subsequently issued to or licensed by us will not be successfully challenged in the future. In addition, there can be no assurance that our patents will not be infringed or that the coverage of our patents will not be successfully avoided by competitors through design innovation.

        We are aware that others, including universities and companies, have filed patent applications and have been granted patents in the United States and other countries which claim subject matter potentially useful or necessary to the commercialization of our products. The ultimate scope and validity of existing or future patents which have been or may be granted to third parties, and the availability and cost of acquiring rights in those patents necessary to the manufacture, use or sale of our products presently cannot be determined by Celldex.us.

        Third parties may have or may obtain valid and enforceable patents or proprietary rights that could block Celldexus from developing products using Celldex'sour technology, including:

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certain patents and applications in the United States and Europe owned by Sanofi-Aventis, which relate to antibody-antigen conjugates and methods of their use for eliciting an immune response against the antigen;