Exhibit 99.1


(HYBRIDON LOGO)


Contacts:

Hybridon, Inc.                                       MacDougall Communications
617-679-5500, x5517                                  508-647-0209 x12
Robert G. Andersen                                   Douglas MacDougall
E-mail: randersen@hybridon.com                       E-mail:  Doug@macbiocom.com


                    HYBRIDON REPORTS 2004 FINANCIAL RESULTS

        - OPERATIONAL HIGHLIGHTS INCLUDE DRUG DEVELOPMENT FOCUS ON TOLL-
                                LIKE RECEPTORS -

CAMBRIDGE, MA, MARCH 28, 2005 - Hybridon, Inc. (AMEX:HBY) today announced
financial results for the year ended December 31, 2004 in conjunction with the
filing of its Annual Report on Form 10-K for 2004 with the Securities and
Exchange Commission.

The Company reported total revenues in 2004 of $0.9 million and a net loss
applicable to common stockholders in 2004 of $0.16 per share compared with total
revenues of $0.9 million and a net loss applicable to common stockholders of
$0.45 per share in 2003. Research and development expenses were substantially
unchanged at $10.8 million in 2003 and $10.3 million in 2004. General and
administrative expenses decreased from $6.9 million in 2003 to $4.3 million in
2004. Condensed operating results and condensed balance sheet information from
the Form 10-K are included at the end of this press release.

"During 2004, Hybridon completed its transition to a company focused on the
development of novel IMO drug candidates as agonists of Toll-like Receptor 9,"
commented Sudhir Agrawal, D. Phil., President and CEO of Hybridon. "Our lead
compound, IMOxine, has been administered to over 50 healthy subjects and
oncology patients in clinical trials. In 2004, we also initiated a multi-center
Phase 2 trial of IMOxine in renal cell carcinoma and we identified several other
IMO drug candidates for development for the treatment of asthma/allergy and
infectious disease."

Dr. Agrawal continued, "Our IMO pipeline of TLR9 agonists is a result of our
extensive experience with DNA-based therapeutics, including antisense. Given the
data coming out of our TLR9 programs, we have decided to focus substantially all
of our resources on these drug candidates. We plan to seek to enter into
collaborations to continue the development of our antisense programs."

During 2004, Hybridon signed two new antisense collaborations with Alnylam
Pharmaceuticals, Inc. and VasGene Therapeutics, Inc., bringing the total
number of antisense collaborations and licenses to which Hybridon is party
to nine.

ABOUT HYBRIDON

Hybridon, Inc. is a leader in the discovery and development of novel
therapeutics based on synthetic DNA. The Company's focus is to develop
therapeutics independently and with partners based on two proprietary
technology platforms: i) Synthetic immunomodulatory oligonucleotides
(IMO(TM)) that act to modulate responses of the immune system; and ii)
Antisense technology that uses synthetic DNA to block the production of
disease-causing proteins at the cellular level.  Licensees of Hybridon's
technology include Isis Pharmaceuticals, Inc., Alnylam Pharmaceuticals,
Integrated DNA Technologies, Inc., MethylGene, Inc., Aegera Therapeutics,
Inc., Avecia Biotechnology, Inc., VasGene Therapeutics, Inc., Migenix,
Inc., Epigenesis Pharmaceuticals, Inc., and The Immune Response
Corporation.

The Company is conducting Phase 1 and Phase 2 clinical trials in oncology
patients with HYB2055 (IMOxine(R)), a 2nd-generation IMO, and has completed a
Phase 1 trial of HYB2055 in healthy volunteers. Hybridon has licensed
Amplivax(TM) (an adjuvant application of HYB2055) as an adjuvant in IR103, a
potential therapeutic and prophylactic vaccine for HIV infection being developed
by The Immune Response Corporation. Hybridon also is collaborating on the
development of additional 2nd-generation antisense oligonucleotides for the
treatment of cancer and viral infections.

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 or early clinical trials 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 United States Food and Drug Administration or
equivalent foreign regulatory agencies; whether, if such products receive
approval, they will be successfully distributed and marketed; whether the
Company will be able to enter into and maintain collaborations with third
parties; whether the patents 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 current Annual Report on Form 10-K filed on
March 25, 2005, which important factors are incorporated herein by reference.
Hybridon disclaims any intention or obligation to update any forward-looking
statements.


                           - Financial charts follow -

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




                                                        Years Ended December 31,
                                                        2004             2003
                                                      --------         --------
                                                                 
Revenues                                              $    942         $    897
Operating Expenses
   Research & Development                               10,305           10,817
   General & Administrative                              4,273            6,924
   Stock-based Compensation                               (713)             543
                                                      --------         --------
   Total Operating Expenses                             13,865           18,284
                                                      --------         --------
(Loss) from Operations                                 (12,923)         (17,387)
Investment Income                                          217              294
Interest Expense                                           (29)            (118)
                                                      --------         --------
Net (Loss)                                             (12,735)         (17,211)
Accretion of Preferred Stock Dividends                  (2,676)          (5,529)
                                                      --------         --------
Net (Loss) Applicable To
   Common Stockholders                                $(15,411)        $(22,740)
                                                      ========         ========
Basic and Diluted Net (Loss) Per
Common Share                                          $  (0.16)        $  (0.45)
                                                      ========         ========

Shares Used In Computing Basic and
Diluted Net (Loss) Per Common Share                     98,914           51,053
                                                      ========         ========



                                 Hybridon, Inc.
                    Consolidated Condensed Balance Sheet Data
                                 (In thousands)




                                                            At December 31,
                                                        2004              2003
                                                       -------           -------
                                                                   
Cash, Cash Equivalents
   And Investments                                     $14,413           $13,668
Receivables & Other Assets                                 978               742
                                                       -------           -------
Total Assets                                           $15,391           $14,410
                                                       =======           =======

9% Notes Payable                                       $    --           $ 1,306
Other Current Liabilities                                1,687             1,799
Non-Current Portion of Accrued
   Expenses                                                240                --
Deferred Revenue                                           695               779
Total Stockholders' Equity                              12,769            10,526
                                                       -------           -------
Total Liabilities &
   Stockholders' Equity                                $15,391           $14,410
                                                       =======           =======


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