Celldex Presents CDX-1127 In Vitro Human Data Consistent With Strong Potency and Safety Profile at AACR 2013

Celldex Presents CDX-1127 In Vitro Human Data Consistent With Strong Potency
and Safety Profile at AACR 2013

         --Results Directly Complement Ongoing Clinical Development--

NEEDHAM, Mass., April 8, 2013 (GLOBE NEWSWIRE) -- Celldex Therapeutics, Inc.
(Nasdaq:CLDX) today reported the results of an in vitro study analyzing the
activation of human T cells with CDX-1127. CDX-1127 is a monoclonal antibody
that binds CD27 and is designed to activate patients' immune cells against
their cancer. The study further explored aspects related to both the potency
and safety profile of CDX-1127. Results were consistent with earlier work,
confirming the mechanism of action for CDX-1127 and providing additional
support for continued clinical development of the candidate. The data were
presented in a poster (#1239) entitled "Characterization of the Response of
Human T cells to an Agonist Human Anti-CD27 mAb" at the American Association
of Cancer Research (AACR) Annual Meeting in Washington DC by Tibor Keler, PhD,
Senior Vice President and Chief Scientific Officer of Celldex Therapeutics.

"The results of this study confirm that CDX-1127 elicits potent activation of
T cells by inducing their proliferation and release of important immune
modulating cytokines," said Dr. Keler. "Most importantly, we have shown that
the activation is highly regulated, which limits any safety concerns related
to non-specific stimulation of the immune system that similar candidates in
this class have faced. This finding is supported by the good safety profile
seen to date in our ongoing multi-dose Phase 1 human clinical trial. We
believe CDX-1127 is an exciting entrant to the field of immunotherapy and look
forward to presenting clinical data from planned solid tumor and hematologic
expansion cohorts from our Phase 1 study by year-end."

Study results:

This study investigated the mechanistic requirements for T cell activation by
CDX-1127 and the resulting characteristics of the activated T cells. Using
purified T cells from healthy subjects, the results of this study demonstrated
that concomitant signaling through the T Cell Receptor for antigen is required
for CDX-1127 drug activity. Therefore, widespread activation of T cells (since
the vast majority are not receiving T Cell Receptor signaling) will not be
activated by CDX-1127. Importantly, when T cells are activated through T cell
receptor stimulation and CDX-1127, they undergo multiple cell divisions,
secrete cytokines with a dominant a proinflammatory signature (IFNγ, IL-2 and
TNFα), and express activation markers consistent with an activated phenotype.
Gene expression microarray analysis revealed modulation of intracellular
signaling, protein kinases, growth and cytokine-chemokine pathways. These in
vitro characterizations will be used to guide the biomarker analysis of
subjects in the CDX-1127 Phase 1 trial to assess in vivo T cell activation. A
copy of this poster is available for viewing in the Scientific Publications
section of the Celldex website under the header "Human Monoclonal Antibody
Programs: CD27."

About Celldex Therapeutics, Inc.

Celldex develops targeted therapeutics to address devastating diseases for
which available treatments are inadequate. Our pipeline is built from a
proprietary portfolio of antibodies and immunomodulators used alone and in
strategic combinations to create novel, disease-specific therapies that
induce, enhance or suppress the body's immune response.

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, 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 limited cash reserves and 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 have initiated or plan to initiate; our ability to adapt our APC
Targeting Technology^TM 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
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 factors listed under "Risk Factors" in our
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 release.
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.

CONTACT: Sarah Cavanaugh
         Vice President of Investor Relations &
         Corp Communications
         Celldex Therapeutics, Inc.
         (781) 433-3161
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