SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                  SCHEDULE 13G
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                              PURSUANT TO 13d-2(b)

                                   ALTEON INC.
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                                (Name of Issuer)

                                  COMMON STOCK
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    02144G107
--------------------------------------------------------------------------------
                                 (CUSIP Number)

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

Check the appropriate box to designate the one pursuant to which this Schedule
is filed:

     [ ]       Rule 13d-1(b)

     [X]       Rule 13d-1(c)

     [ ]       Rule 13d-1(d)



/1/  The remainder of this cover page shall be filled out for a reporting
person's initial filing on this with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in 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 (the "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).




---------------------                                        -------------------
CUSIP NO. 02144G 10 7                 13G                     Page 2 of 5 Pages
---------------------                                        -------------------

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    1          NAME OF REPORTING PERSON
               S.S. or I.R.S. Identification No. Of Above Person

               Ansbert Gadicke

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    2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a)  [ ]

                                                                      (b)  [X]

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    3          SEC USE ONLY

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    4          CITIZENSHIP OR PLACE OF ORGANIZATION
               United States

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           NUMBER OF               5    SOLE VOTING POWER
 SHARES BENEFICIALLY OWNED BY           1,385,000 (1)
             EACH
       REPORTING PERSON          -----------------------------------------------
             WITH                  6    SHARED VOTING POWER
                                        None

                                 -----------------------------------------------
                                   7    SOLE DISPOSITIVE POWER
                                        1,385,000 (1)

                                 -----------------------------------------------
                                   8    SHARED DISPOSITIVE POWER
                                        None

--------------------------------------------------------------------------------
    9          AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
               1,385,000 (1)

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   10          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
               CERTAIN SHARES*    [ ]

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   11          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
               5.1%

--------------------------------------------------------------------------------
   12          TYPE OF REPORTING PERSON*
               IN

--------------------------------------------------------------------------------
               *SEE INSTRUCTIONS BEFORE FILLING OUT!






---------------------                                        -------------------
CUSIP NO. 02144G 10 7                 13G                     Page 3 of 5 Pages
---------------------                                        -------------------

Item 1 (a).    Name of Issuer:

               Alteon Inc.
               -----------------------------------------------------------------


Item 1 (b).    Address of Issuer's Principal Executive Offices:

               170 Williams Drive, Ramsey NJ 07446
               -----------------------------------------------------------------


Item 2 (a).    Name of Person Filing:

               Ansbert Gadicke
               -----------------------------------------------------------------


Item 2 (b).    Address of Principal Business Office or, if none, Residence:

               c/o MPM Capital L.P., 111 Huntington Avenue, 31st floor,
               Boston, MA 02199
               -----------------------------------------------------------------


Item 2 (c).    Citizenship:

               United States
               -----------------------------------------------------------------


Item 2 (d).    Title of Class of Securities:

               Common Stock
               -----------------------------------------------------------------


Item 2 (e).    CUSIP Number:

               02144G107
               -----------------------------------------------------------------


Item 3.   If This Statement Is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or
          (c), Check Whether the Person Filing is a:

          (a)  [ ]  Broker or dealer registered under Section 15 of the
                    Exchange Act,

          (b)  [ ]  Bank as defined in Section 3(a)(6) of the Exchange Act,

          (c)  [ ]  Insurance company as defined in Section 3(a)(19) of the
                    Exchange Act,

          (d)  [ ]  Investment company registered under Section 8 of the
                    Investment Company Act,

          (e)  [ ]  An investment adviser in accordance with
                    Rule 13d-1(b)(1)(ii)(E),

          (f)  [ ]  An employee benefit plan or endowment fund in accordance
                    with Rule 13d-1(b)(1)(ii)(F),

          (g)  [ ]  A parent holding company or control person, in accordance
                    with Rule 13d-1(b)(1)(ii)(G),

          (h)  [ ]  A savings association as defined in Section 3(b) of the
                    Federal Deposit Insurance Act,

          (i)  [ ]  A church plan that is excluded from the definition of an
                    investment company under Section 3(c)(14) of the Investment
                    Company Act,

          (j)  [ ]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).




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CUSIP NO. 02144G 10 7                 13G                     Page 4 of 5 Pages
---------------------                                        -------------------


Item 4.   Ownership.

          (a)  Amount beneficially owned:

               1,385,000 (1)
          ----------------------------------------------------------------------

          (b)  Percent of class:

               5.1%
          ----------------------------------------------------------------------

          (c)  Number of shares as to which such person has:

               (i)    sole power to vote or to direct the vote
                      1,385,000 (1)
               -----------------------------------------------------------------

               (ii)   shared power to vote or to direct the vote
                      None
               -----------------------------------------------------------------

               (iii)  sole power to dispose or to direct the disposition of
                      1,385,000 (1)
               -----------------------------------------------------------------

               (iv)   shared power to dispose or to direct the disposition of
                      None
               -----------------------------------------------------------------


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.

          Various persons have the right to receive or the power to direct the
          receipt of dividends from, or the proceeds from the sale of, the
          shares to which this statement relates. No one person's interest in
          such shares is more than five percent of the total outstanding stock
          of the Issuer.
          ----------------------------------------------------------------------


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.

          Not applicable
          ----------------------------------------------------------------------


Item 9.   Notice of Dissolution of Group.

          Not applicable
          ----------------------------------------------------------------------


Item 10.  Certifications.

          Not applicable
          ----------------------------------------------------------------------


/1/ Includes shares held through entities advised and/or managed by MPM
BioEquities Adviser LLC ("MPM BioEquities Adviser") and the general partners and
control person of such entities. MPM BioEquities Adviser is controlled by MPM
Capital II GP LLC and is the adviser of MPM BioEquities Master Fund L.P., the
direct and indirect general partners of which are MPM BioEquities GP L.P. and
MPM BioEquities GP LLC. 1,385,000 of the shares are held of record by MPM
BioEquities Master Fund L.P. Each reporting person herein disclaims beneficial
ownership of shares not directly held by such person.





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CUSIP NO. 02144G 10 7                 13G                     Page 5 of 5 Pages
---------------------                                        -------------------

                                                                       SIGNATURE

     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.

                                                     February 13, 2002
                                             --------------------------------
                                                            Date

                                                    /s/ Ansbert Gadicke
                                             --------------------------------
                                                          Signature

                                                       Ansbert Gadicke
                                             --------------------------------
                                                         Name/Title