Celldex Announces Full Exercise of Underwriters' Option to Purchase Additional Shares

Celldex Announces Full Exercise of Underwriters' Option to Purchase Additional
Shares

NEEDHAM, Mass., Feb. 8, 2013 (GLOBE NEWSWIRE) -- Celldex Therapeutics, Inc.
(Nasdaq:CLDX) today announced that the underwriters of its previously
announced public offering of common stock have exercised in full their option
to purchase an additional 1,800,000 shares of common stock at the public
offering price of $7.50 per share, less underwriting discounts and
commissions. Proceeds from the exercise of the option will be approximately
$12.7 million, after deducting underwriting discounts and commissions. The
closing of the option exercise is expected to occur on February 11, 2013,
subject to customary closing conditions.

As previously announced, Celldex anticipates using the net proceeds from the
offering, including the net proceeds from the exercise of the option to
purchase additional shares, to fund Celldex's clinical trials of its product
candidates and for working capital and other general corporate purposes.

Jefferies & Company, Inc. and Leerink Swann LLC acted as joint book-running
managers of the offering. Oppenheimer & Co., Wedbush PacGrow Life Sciences,
Brean Capital and Roth Capital Partners, LLC acted as co-managers of the
offering.

A shelf registration statement relating to the shares was filed with the
Securities and Exchange Commission (SEC) and is effective. The final
prospectus supplement related to the offering has been filed with the SEC and
is available on the SEC's website located at http://www.sec.gov. Copies of the
final prospectus supplement and accompanying prospectus may be obtained from
Jefferies & Company, Inc., Attention: Equity Syndicate Prospectus Department,
520 Madison Avenue, 12th Floor, New York, NY, 10022, by telephone at
877-547-6340 or by email at Prospectus_Department@Jefferies.com or from
Leerink Swann LLC, Attention: Syndicate Department, One Federal Street, 37th
Floor, Boston, MA 02110, by telephone at 1-800-808-7525 or by email at
Syndicate@Leerink.com.

This press release shall not constitute an offer to sell or the solicitation
of an offer to buy these securities, nor shall there be any sale of these
securities in any state or other jurisdiction in which such offer,
solicitation or sale would be unlawful prior to the registration or
qualification under the securities laws of any such state or other
jurisdiction.

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.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of
1995: This announcement contains "forward-looking statements" such as those,
among others, relating to Celldex's expectations regarding the completion and
timing of the closing of the public offering and its anticipated use of net
proceeds from the offering. These statements are subject to significant risks
and uncertainties; actual results could differ materially from those projected
and Celldex cautions investors not to place undue reliance on the
forward-looking statements contained in this release. These risks and
uncertainties include, without limitation, risks and uncertainties related to
market conditions and satisfaction of customary closing conditions related to
the underwriters' option to purchase additional shares. There can be no
assurance that Celldex will be able to complete the public offering on the
anticipated terms, or at all. Risks and uncertainties relating to Celldex and
its business can be found in the "Risk Factors" section of Celldex's Form
10-K, filed with the SEC on March 8, 2012, and in the prospectus supplement
and related prospectus relating to the proposed offering filed with the SEC on
February 4, 2013. Celldex undertakes no duty or obligation to update any
forward-looking statements contained in this release as a result of new
information, future events or changes in Celldex's expectations.

CONTACT: Sarah Cavanaugh
         Vice President of IR & Corp Communications
         Celldex Therapeutics, Inc.
         (781) 433-3161
         scavanaugh@celldextherapeutics.com