SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13G/A
                                  Rule 13d-102

                    Under the Securities Exchange Act of 1934

                        Interneuron Pharmaceuticals, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, $.001 par value per share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                February 10, 2002
--------------------------------------------------------------------------------

                                    460573108
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                December 31, 2001
--------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

      Check the appropriate box to designate the rule pursuant to which
this Schedule is filed:
                               |_| Rule 13d-1 (b)
                               |X| Rule 13d-1 (c)
                               |_| Rule 13d-1 (d)

----------
*     The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which
would alter disclosures provided in a prior cover page.

      The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).


                                       1


CUSIP No.  460573108                   13G                     Page 2 of 4 Pages
--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Lindsay A. Rosenwald, M.D.
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) |_|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3   SEC USE ONLY

--------------------------------------------------------------------------------
4   CITIZENSHIP OR PLACE OF ORGANIZATION

    United States
--------------------------------------------------------------------------------
                  5    SOLE VOTING POWER

                       2,529,981
                  --------------------------------------------------------------
  NUMBER OF       6    SHARED VOTING POWER
    SHARES
 BENEFICIALLY          None
   OWNED BY       --------------------------------------------------------------
     EACH         7    SOLE DISPOSITIVE POWER
  REPORTING
    PERSON             2,529,981
     WITH         --------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER

                       None
--------------------------------------------------------------------------------
9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    2,529,981
--------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                            |_|
--------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    6.9%
--------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON*

    IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT


                                       2


ITEM 1(a).  NAME OF ISSUER:

            Interneuron Pharmaceuticals, Inc..

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

            One Ledgemount Center
            99 Hayden Avenue
            Lexington, MA 02421

            ITEM 2(a) NAME OF PERSON FILING: Lindsay A. Rosenwald, M.D.

ITEM 2(b)   ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

            Dr. Rosenwald's business address is 787 Seventh Avenue, 48th Floor,
            New York, New York, 10019.

ITEM 2(c).  CITIZENSHIP:

            Dr. Rosenwald is a citizen of the United States of America.

ITEM 2(d).  TITLE OF CLASS OF SECURITIES:

            Common Stock, par value $.001 per share.

ITEM 2(e).  CUSIP NUMBER: 460573108

ITEM 3.     |X| CHECK THIS BOX IF THIS STATEMENT IS FILED PURSUANT TO RULE
            13d-1(c)

ITEM 4.     OWNERSHIP

            For information concerning the ownership of Common Stock of the
            Company by the Reporting Person, see Items 5 through 9 and 11 of the
            cover pages to this schedule 13G and footnotes thereto.

ITEM 5.     OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

            Not applicable

ITEM 6.     OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

            Not applicable

ITEM 7.     IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
            THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

            Not Applicable

ITEM 8.     IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP


                                       3


            Not Applicable

ITEM 9.     NOTICE OF DISSOLUTION OF GROUP

            Not Applicable

ITEM 10.    CERTIFICATION

            By signing below I certify that, to the best of my knowledge and
            belief, the securities referred to above were not acquired and are
            not held for the purpose of or with the effect of changing or
            influencing the control of the issuer of the securities and were not
            acquired and are not held in connection with or as a participant in
            a transaction having that purpose and effect.

                                   SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.


Dated: February 13, 2002                  By: /s/ Lindsay A. Rosenwald, M.D.
New York, NY                                 ----------------------------------
                                             Name: Lindsay A. Rosenwald, M.D.


                                       4