Celldex Therapeutics, Inc. (Nasdaq: CLDX) today announced that new data on its preclinical therapeutic antibody program, CDX-1127, is being presented in a poster presentation at the 2011 American Association for Cancer Research (AACR) 102nd Annual Meeting in Orlando, FL. The presentation (poster #4560) is entitled “Anti-tumor activity of a fully human anti-CD27 monoclonal antibody in a transgenic mouse model” and describes proof-of-concept data in mice and non-human primates with CDX-1127. The presentation is scheduled from 1:00 p.m. to 5:00 p.m. EDT today (Tuesday, April 5) in Exhibit Hall A4-C at the Orange County Convention Center.

CDX-1127 is a fully human monoclonal antibody targeting CD27, a member of the tumor necrosis factor (TNF) receptor superfamily with a critical role in the balance between immunity and tolerance. CDX-1127 has a dual mechanism of action – the antibody can function as an immune modulator through activation of T cells and natural killer cells and it can also function as a conventional antibody by direct activity against tumor cells that express CD27. “We have been diligently moving this program towards clinical development and the results we are presenting at this conference give us confidence on the translation of our findings from preclinical studies into patients with cancer,” said Tibor Keler, Ph.D., Celldex’s Chief Scientific Officer.

Key findings presented in the poster demonstrated the following:

• Mechanism of Action Studies: Demonstrated the agonistic function of CDX-1127 in combination with T cell receptor activation;
• Efficacy Studies: Demonstrated potent therapeutic effects of CDX-1127 in an aggressive tumor model with immune competent human CD27-transgenic mice; and
• Safety Studies: Demonstrated tolerability and lack of cytokine release in a pilot non-human primate study.

“With the approval of ipilimumab, there is growing enthusiasm for the potential of immune system modulating antibodies in helping cancer patients and CDX-1127 combines both immune modulation and conventional antibody functions into one antibody,” said Anthony S. Marucci, President and Chief Executive Officer of Celldex Therapeutics, Inc. “We are looking forward to initiating clinical development of CDX-1127 later this year, adding to our growing pipeline of product candidates in our Precision Targeted Immunotherapy Platform.”

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 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 (formerly known as CDX-110), CDX-011, CDX-1307, CDX-1135 (formerly TP10), CDX-1401, CDX-1127, and CDX-301. 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 successfully commercialize, multiple technologies and programs; 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; our development partners’ willingness to make announcements with respect to co-developed products; the uncertainties inherent in clinical testing; our ability to manage research and development efforts for multiple products at varyingstages of development; approvals; the failure of the market for the Company's programs to continue to develop; 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.