EXHIBIT 99.1

[HYBRIDON LOGO]

                              FOR IMMEDIATE RELEASE

Contacts:

Hybridon, Inc.                               Noonan Russo Presence Euro RSCG
617-679-5500, x5517                          212-845-4269
Robert G. Andersen                           Brian Ritchie (media and investors)
E-mail:  randersen@hybridon.com


HYBRIDON, INC. ANNOUNCES FINANCIAL RESULTS FOR 2002

CAMBRIDGE, MA, APRIL 2, 2003 - Hybridon, Inc. (OTC Bulletin Board: HYBN.OB)
announced today its financial results for 2002. For the twelve months ended
December 31, 2002, the Company's revenue was $30.3 million as compared with $1.7
million for the same period in 2001. The $30.3 million in revenue included $27.9
million in revenue derived from a one-time recognition of previously deferred
revenue received under a Collaboration and License Agreement with Isis
Pharmaceuticals, Inc. Net income applicable to common stockholders was $12.7
million or $0.27 per basic share for the period as compared with a loss
applicable to common stockholders of $13.7 million or $0.44 per basic share for
2001. The Company had more than $20 million in cash, cash equivalents and
investments at year end.

Research and development expenditures for 2002 increased to $7.9 million from
$4.9 million for the same period in 2001. This increase was primarily
attributable to advancement of the Company's drug development program in 2002,
including clinical trials of GEM(R)231, Hybridon's 2nd generation antisense
compound for solid tumor cancers, and the expansion of pre-clinical activity
related to Hybridon's immunomodulatory oligonucleotide (IMO(TM)) program leading
to an IND filing for HYB2055. General and administrative expenses increased to
$7.1 million in 2002 from $5.1 million in 2001. The $2 million increase was due
to recognition of $2.1 million of deferred expenses as a result of the August,
2002 amendment to the Collaboration and License agreement with Isis. Interest
expense for 2002 decreased to $0.2 million from $1.3 million in 2001 as a

result of note conversions and repayments undertaken to streamline the Company's
balance sheet in 2001.

"As a company we made significant progress in 2002 and laid the groundwork for
achievements in 2003," said Stephen R. Seiler, Hybridon's Chief Executive
Officer. "We have established Hybridon as a leader in the discovery and
development of therapeutics based on synthetic DNA. Among the highlights of last
year are:

      -     The commencement of a phase 1/2 clinical trial in cancer patients
            using a combination of GEM(R)231, Hybridon's 2nd generation
            antisense compound, and Camptosar(R).

      -     The selection of HYB2055 as the lead compound in our IMO(TM)
            therapeutics program.

      -     The signing of two collaboration and licensing agreements regarding
            our antisense technology. Our partners in the collaborations are
            Micrologix Biotechnology, Inc. and Aegera Therapeutics Inc.

      -     Ending the year with more than $20 million in cash, cash equivalents
            and investments, which puts us in a position aggressively to pursue
            our goals for 2003.

      -     The addition to our board of directors of William S. Reardon, CPA
            and Georges Anthony Marcel, M.D., Ph.D. Bill is a retired audit
            partner of PricewaterhouseCoopers LLP, where he led the Life Science
            Industry Practice for New England and the Eastern United States.
            Tony's previous experience includes roles as President and CEO of
            the French subsidiary of Amgen, Inc. and CEO of Laboratoires
            Roussel. He is a member of the Gene Therapy Committee of the French
            Medicines Agency, which is the French equivalent of the U.S. Food
            and Drug Administration. He is also a Member of the Board of St.
            Honore Vie et Sante, a healthcare investment fund of the Rothschild
            Group."

"All of us at Hybridon look forward eagerly to exploiting and expanding on our
leadership in synthetic DNA-based therapeutics by developing important new drugs
to prevent, treat and cure disease," concluded Mr. Seiler.

ABOUT HYBRIDON

Hybridon, Inc. is a leader in the discovery and development of novel
therapeutics and diagnostics, using synthetic DNA. The Company now has

four technology platforms: 1) Immunomodulatory oligonucleotide (IMO(TM))
compounds that use synthetic DNA to modulate responses of the immune system; 2)
Antisense technology which uses synthetic DNA to block the production of
disease-causing proteins at the cellular level; 3) Synthetic DNA to enhance the
antitumor activity of certain marketed anticancer drugs, thereby increasing
their effectiveness; and 4) Cyclicon(TM) technology that uses novel synthetic
DNA structures for identifying gene function for target validation and drug
discovery.

This press release contains forward-looking statements concerning Hybridon that
involve a number of risks and uncertainties. For this purpose, any statements
contained herein that are not statements of historical fact may be deemed to be
forward-looking statements. Without limiting the foregoing, the words,
"believes," "anticipates," "plans," "expects," "estimates," "intends," "should,"
"could," "will," "may," and similar expressions are intended to identify
forward-looking statements.

There are a number of important factors that could cause Hybridon's actual
results to differ materially from those indicated by such forward-looking
statements including risks as to whether results obtained in preclinical
studies, such as the results referred to in this press release, will be
indicative of results obtained in future preclinical studies or clinical trials,
or warrant further clinical trials and product development; whether products
based on Hybridon's technology will advance through the clinical trial process
and receive approval from the US Food and Drug Administration or equivalent
foreign regulatory agencies; whether, if such products receive approval, they
will be successfully distributed and marketed; whether the patent and patent
applications owned or licensed by Hybridon will protect the Company's technology
and prevent others from infringing it; whether Hybridon's cash resources will be
sufficient to fund product development and such other important factors as are
set forth under the caption "Risk Factors" in Hybridon's Annual Report on Form
10-K for the year ended December 31, 2002, which important factors are
incorporated herein by reference.

These forward-looking statements should not be relied upon as representing
Hybridon's views as of any date subsequent to the date of this release and
Hybridon disclaims any obligation to update these forward-looking statements.

This and other Hybridon press releases can be found at http://www.hybridon.com
and http://www.nrp-euro.com.

                                       ###

                                 Hybridon, Inc.
                 Consolidated Condensed Statement of Operations
                      (In thousands except per share data)



                                                      Year Ended December 31,
                                                --------------------------------
                                                   2002                  2001
                                                ----------            ----------
                                                                
Revenues                                        $   30,256            $    1,699
Operating Expenses:
   Research & Development                            7,877                 4,868
   General & Administrative                          7,054                 5,051
   Stock-based Compensation                         (1,297)                1,762
   Interest Expense                                    150                 1,319
                                                ----------            ----------
  Total Operating Expenses                          13,784                13,000
Gain from Sale of Securities, net                     ----                 5,217
Income (Loss) from Discontinued
  Operations                                          ----                 2,663
Income Tax Credit (provision)                          500                  (500)
Extraordinary Loss from Conversion
  of 8% Notes                                         ----                (1,412)
                                                ----------            ----------
Net Income (Loss)                               $   16,972            $   (5,333)
Accretion of Preferred Stock Dividends              (4,246)               (8,342)
                                                ----------            ----------
Net Income (Loss) To Common
    Stockholders                                $   12,726            $  (13,675)
                                                ==========            ==========
Net Income (Loss) Per Common Share

    Basic                                       $     0.27            $    (0.44)
                                                ==========            ==========
    Diluted                                     $     0.24            $    (0.44)
                                                ==========            ==========
Shares Used In Computing Net
    Income (Loss) Per Common Share

    Basic                                           46,879                30,820
                                                ==========            ==========
    Diluted                                         52,984                30,820
                                                ==========            ==========


                    Consolidated Condensed Balance Sheet Data
                                 (In thousands)



                                                         At December 31,
                                                --------------------------------
                                                   2002                  2001
                                                ----------            ----------
                                                                
Cash, Cash Equivalents
    and Short-Term Investments                  $   19,175            $   31,834
Long-term Investments                                  941                  ----
Receivables and Other Assets                         1,133                   475
                                                ----------            ----------
Total Assets                                    $   21,249            $   32,309
                                                ==========            ==========
Current Liabilities                             $    2,136            $    4,906
9% Note Payable                                      1,306                 1,306



                                                                
Deferred Revenue                                       363                26,130
Total Stockholders' Equity                          17,444                   (33)
                                                ----------            ----------
Total Liabilities and
Stockholder's Equity                            $   21,249            $   32,309
                                                ==========            ==========