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                                UNITED STATES                    SEC File Number
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549                 ------------
                                                                   Cusip Number
                                 FORM 12b-25                       ------------

                       Commission File Number:  333-3954
                          NOTIFICATION OF LATE FILING

(Check One) [ ]Form 10-K [ ]Form 20-F [ ]Form 11-K  [X]Form 10-Q [ ]Form N-SAR

                 For Period Ended: June 30, 2001
                                   -------------
                 [  ]     Transition Report on Form 10-K
                 [  ]     Transition Report on Form 20-F
                 [  ]     Transition Report on Form 11-K
                 [  ]     Transition Report on Form 10-Q
                 [  ]     Transition Report on Form N-SAR
                 For the Transition Period Ended:
                                                  ---------------------------

 READ ATTACHED INSTRUCTION SHEET BEFORE PREPARING FORM.  PLEASE PRINT OR TYPE

   Nothing in the form shall be construed to imply that the Commission has
                  verified any information contained herein.

    If the notification relates to a portion of the filing checked above,
           identify the Item(s) to which the notification relates:

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                       PART I - REGISTRANT INFORMATION

Hybridon, Inc.
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Full Name of Registrant


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Former Name if Applicable

345 Vassar Street
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Address of Principal Executive Office (STREET AND NUMBER)

Cambridge, MA 02139
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City, State and Zip Code


                      PART II - RULES 12b-25(b) and (c)

If the subject report could not be filed without unreasonable effort or expense
and the registrant seeks relief pursuant to Rule 12b-25(b), the following
should be completed.  (Check box if appropriate.)

 [X]     (a)     The reasons described in reasonable detail in Part III of this
                 form could not be eliminated without unreasonable effort or
                 expense;

 [X]     (b)     The subject annual report, semi-annual report, transition
                 report on Form 10-K, Form 20-F, 11-K, Form N-SAR, or portion
                 thereof, will be filed on or before the 15th calendar day
                 following the prescribed due date; or the subject quarterly
                 report or transition report on Form 10-Q, or portion thereof
                 will be filed on or before the fifth calendar day following
                 the prescribed due date; and

 [ ]     (c)     The accountant's statement or other exhibit required by Rule
                 12b-25(c) has been attached if applicable.

                             PART III - NARRATIVE

State below in reasonable detail the reasons why the Form 10-K, 11-K, 10-Q,
N-SAR, or the transition report or portion thereof, could not be filed within
the prescribed time period.  (Attach Extra Sheets if Needed)

The Registrant was unable to file its Quarterly Report on Form 10-Q on August
14, 2001, because it was unable to reach a final determination of approximate
revenue recognition principles applicable to a material transaction in the time
available without unreasonable effort or expense.
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                         PART IV - OTHER INFORMATION

(1)      Name and telephone number of person to contact in regard to this
         notification

              Robert Andersen               617                 679-5500
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                  (Name)                (Area Code)        (Telephone Number)


(2)      Have all other periodic reports required under Section 13 or 15(d) of
         the Securities Exchange Act of 1934 or Section 30 of the Investment
         Company Act of 1940 during the preceding 12 months or for such shorter
         period that the registrant was required to file such report(s) been
         filed?  If the answer is no, identify report(s).
         [X] Yes  [ ] No

(3)      Is it anticipated that any significant change in results of operations
         from the corresponding period for the last fiscal year will be
         reflected by the earnings statements to be included in the subject
         report or portion thereof?  [X] Yes  [ ] No

         If so, attach an explanation of the anticipated change, both
         narratively and quantitatively, and, if appropriate, state the reasons
         why a reasonable estimate of the results cannot be made: But the
         financial impact of the material transaction in question has previously
         been disclosed in a Form 8-K: only the timing of recognition is not yet
         finalized for financial reporting purposes.

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                                 Hybridon, Inc.
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                  (Name of Registrant as Specified in Charter)


Has caused this notification to be signed on its behalf by the undersigned
thereunto duly authorized.


Date August 14, 2001                 By /s/ Robert Andersen
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                                       Name:  Robert Andersen
                                       Title: Chief Financial Officer
                                       and Vice President of Planning
                                       and Operations

INSTRUCTION:  The form may be signed by an executive officer of the registrant
or by any other duly authorized representative.  The name and title of the
person signing the form shall be typed or printed beneath the signature.  If
the statement is signed on behalf of the registrant by an authorized
representative (other than an executive officer), evidence of the
representative's authority to sign on behalf of the registrant shall be filed
with the form.

                                   ATTENTION
  Intentional misstatements or omissions of fact constitute Federal Criminal
                       Violations (See 18 U.S.C. 1001).


                              GENERAL INSTRUCTIONS

1.       This form is required by Rule 12b-25 of the General Rules and
         Regulations under the Securities Exchange Act of 1934.

2.       One signed original and four conformed copies of this form and
         amendments thereto must be completed and filed with the Securities and
         Exchange Commission, Washington, D.C. 20549 in accordance with Rule 0-3
         of the General Rules and Regulations under the Act.  The information
         contained in or filed with the form will be made a matter of public
         record in the Commission files.

3.       A manually signed copy of the form and amendments thereto shall be
         filed with each national securities exchange on which any class of
         securities of the registrant is registered.

4.       Amendments to the notifications must also be filed on form 12b-25 but
         need not restate information that has been correctly furnished.  The
         form shall be clearly identified as an amendment notification.

5.       ELECTRONIC FILERS.  This form shall not be used by electronic filers
         unable to timely file a report solely due to electronic difficulties.
         Filers unable to submit a report within the time period prescribed due
         to difficulties in electronic filing should comply with either Rule
         201 or Rule 202 of Regulation S-T or apply for an adjustment in filing
         date pursuant to Rule 13(b) of Regulation S-T.