Celldex Therapeutics, Inc. (Nasdaq: CLDX) today announced that the European Medicines Agency (EMA) has granted orphan drug designation for rindopepimut for the treatment of Glioblastoma (GB). GB is the most common and aggressive form of brain cancer. Rindopepimut is an immunotherapy that targets the tumor-specific oncogene (a growth promoter), EGFRvIII.

“Obtaining orphan designation for rindopepimut in the European Union (EU) is an important regulatory milestone for Celldex,” said Anthony S. Marucci, President and Chief Executive Officer of Celldex Therapeutics. “The benefits include 10 years of market exclusivity from product launch in the EU, fee reductions, as well as access to the central authorization procedure. We have already been granted Orphan Drug designation for this program by the FDA, which allows for 7 years of market exclusivity from product launch in the U.S. as well as Fast Track designation to accelerate the review of rindopepimut.”

“These orphan drug designations support our global development strategy for rindopepimut and our goal of providing improved therapies for patients with EGFRvIII positive glioblastoma,” said Dr. Thomas Davis, Senior Vice President and Chief Medical Officer of Celldex Therapeutics. “Our clinical experience to date with rindopepimut has demonstrated its potential in prolonging overall survival in front-line EGFRvIII expressing glioblastoma, where limited treatment options exist. This activity, paired with a favorable safety profile, underpins our plans to move forward with the initiation of a Phase 3 study of this program by year-end 2011.”

After consultations with both U.S. and EU regulatory authorities, Celldex has finalized the clinical protocol for the Phase 3 randomized, double-blind study of rindopepimut in GB. The primary endpoint of the study will be overall survival. The study, named ACT IV, is expected to enroll up to 374 patients with newly-diagnosed, fully resected, EGFRvIII expressing GB from over 150 clinical sites internationally. Enrollment is expected to begin in the fourth quarter of 2011.

Also during the fourth quarter of 2011, Celldex expects to initiate a Phase 2 randomized study of rindopepimut in combination with Avastin® in recurrent or refractory GB patients with EGFRvIII expression (the ReACT study). The ReACT study is expected to enroll up to 95 patients in the U.S. and will evaluate objective response rates (ORR), progression free survival (PFS) and overall survival (OS) endpoints in this patient population.

EMA’s Orphan Medicinal Product Designation is designed to promote the development of drugs that may provide significant benefit to patients suffering from rare, life-threatening diseases. In addition to 10 years of market exclusivity if rindopepimut is approved for the treatment of GB, the designation also provides special incentives for sponsors including eligibility for protocol assistance and possible exemptions or reductions in certain regulatory fees during development or at the time of application for marketing approval.

Similarly, FDA orphan drug designation is intended to encourage companies to develop therapies for the treatment of diseases that affect fewer than 200,000 individuals in the United States. This designation will provide Celldex Therapeutics with 7 years of marketing exclusivity for rindopepimut in EGFRvIII positive GB if rindopepimut is approved by the FDA in such indication. Prior to FDA approval, orphan designation by the FDA provides the opportunity to obtain grant funding to defray costs of clinical trial expenses, tax credits for clinical research expenses and potential waiver of the FDA’s application user fees.

About Rindopepimut

Rindopepimut is an investigational immunotherapy that targets the tumor specific molecule EGFRvIII, a functional variant of the epidermal growth factor receptor (EGFR), which is a protein that has been well validated as a target for cancer therapy. This particular variant, EGFRvIII, occurs in about 30 percent of glioblastoma patients. Unlike EGFR, EGFRvIII is not present in normal tissues suggesting this target will enable the development of a tumor- specific therapy for cancer patients. Furthermore, EGFRvIII is a transforming oncogene that can directly contribute to cancer cell growth. While originally discovered in GB, the most common and aggressive form of brain cancer, the expression of EGFRvIII has also been observed in various other cancers such as breast, ovarian, metastatic prostate, colorectal, and head & neck cancers. Celldex has exclusive rights to EGFRvIII vaccines and is pursuing the development of rindopepimut for GB therapy, as well as for other cancers through additional clinical studies.

About Celldex Therapeutics, Inc.

Celldex Therapeutics is the first antibody-based combination immunotherapy company. Celldex has a pipeline of drug candidates in development for the treatment of cancer and other difficult-to-treat diseases based on its antibody focused Precision Targeted Immunotherapy (PTI) Platform. The PTI Platform is a complementary portfolio of monoclonal antibodies, antibody-targeted vaccines and immunomodulators used in optimal combinations to create novel disease-specific drug candidates. For more information, please visit http://www.celldextherapeutics.com.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995: This release contains “forward-looking statements” made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including those related to the Company’s strategic focus and the future development and commercialization (by Celldex and others) of rindopepimut (CDX-110), CDX-011, CDX-1135 (formerly TP10), CDX-1401, CDX-1127, CDX-301, Belinostat and other products. Forward-looking statements reflect management's current knowledge, assumptions, judgment and expectations regarding future performance or events. Although management believes that the expectations reflected in such statements are reasonable, they give no assurance that such expectations will prove to be correct and you should be aware that actual results could differ materially from those contained in the forward-looking statements. Forward-looking statements are subject to a number of risks and uncertainties, including, but not limited to, our ability to obtain additional capital on acceptable terms, or at all, including the additional capital which will be necessary to complete the clinical trials that we plan to initiate in 2011; our ability to adapt APC Targeting TechnologyTM to develop new, safe and effective vaccines against oncology and infectious disease indications; our ability to successfully complete product research and further development of our programs; the uncertainties inherent in clinical testing; our limited experience in bringing programs through Phase 3 clinical trials; our ability to manage research and development efforts for multiple products at varying stages of development; the timing, cost and uncertainty of obtaining regulatory approvals; the failure of the market for the Company's programs to continue to develop; our limited cash reserves and our ability to obtain additional capital on acceptable terms, or at all; our ability to protect the Company’s intellectual property; the loss of any executive officers or key personnel or consultants; competition; changes in the regulatory landscape or the imposition of regulations that affect the Company’s products; and other risks detailed from time to time in the Company's filings with the Securities and Exchange Commission, including the Company's Form 10-K for the fiscal year ended December 31, 2010, and its Forms 10-Q and 8-K.

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