UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934

                                (Amendment No. )*


                         Avant Immunotherapeutics, Inc.
                                (Name of Issuer)

                          Common Stock, $.01 par value
                         (Title of Class of Securities)

                                    053491106
                                 (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:

                                   [x]      Rule 13d-1(b)
                                   [ ]      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 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 ("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. 001084102 13G Page 2 of 7 Pages 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Forstmann-Leff Associates, LLC 52-2169043 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ] (b) [ ] 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware 5 SOLE VOTING POWER NUMBER OF SHARES None BENEFICIALLY OWNED BY 6 SHARED VOTING POWER EACH REPORTING 3,888,500 shares PERSON WITH 7 SOLE DISPOSITIVE POWER None 8 SHARED DISPOSITIVE POWER 3,888,500 shares 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,888,500 shares (includes shares beneficially owned by FLA Advisers L.L.C.) 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 6.8% 12 TYPE OF REPORTING PERSON IA, OO

CUSIP NO. 001084102 13G Page 3 of 7 Pages 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON FLA Advisers L.L.C. 13-3942422 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ] (b) [ ] 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION New York 5 SOLE VOTING POWER NUMBER OF SHARES None BENEFICIALLY OWNED BY 6 SHARED VOTING POWER EACH REPORTING 3,888,500 shares PERSON WITH 7 SOLE DISPOSITIVE POWER None 8 SHARED DISPOSITIVE POWER 3,888,500 shares 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,888,500 shares 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 6.8% 12 TYPE OF REPORTING PERSON IA, OO

Page 4 of 7 Pages Item 1(a) NAME OF ISSUER: Avant Immunotherapeutics, Inc. Item 1(b) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES: 119 Fourth Avenue Needham, MA 02494 Item 2(a) NAME OF PERSON FILING: See Item 1 of the cover pages attached hereto Item 2(b) Address of Principal Business Office, or if none, residence: 590 Madison Avenue New York, New York 10022 Item 2(c) CITIZENSHIP: See Item 4 of the cover pages attached hereto Item 2(d) TITLE OF CLASS OF SECURITIES: Common Stock, par value $.01 Item 2(e) CUSIP NUMBER: 053491106 Item 3 Forstmann-Leff Associates, LLC, a Delaware limited liability company,is a registered investment adviser under Section 203 of the Investment Advisers Act of 1940 (the "Act"). FLA Advisers L.L.C., a New York limited liability company, is a registered investment adviser under the Act. The members of Forstmann-Leff Associates, LLC's Investment Committee are also the managers of FLA Advisers L.L.C.

Page 5 of 7 Pages Item 4 OWNERSHIP: (a) Amount beneficially owned: See Item 9 of the cover pages attached hereto (b) Percent of Class: See Item 11 of the cover pages attached hereto (c) See Items 5 through 8 of the cover pages attached hereto 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 clients of the reporting persons have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock of Avant Immunotherapeutics, Inc. No one client's interest in the Common Stock of Avant Immunotherapeutics, Inc. is more than five percent of the total outstanding Common Stock. 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 CERTIFICATION: By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and 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 any transaction having that purpose or effect.

Page 6 of 7 Pages 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. February 14, 2002 FORSTMANN-LEFF ASSOCIATES, LLC By: /s/ Joseph Sullivan Chief Operating Officer FLA ADVISERS L.L.C. By: /s/ Joseph Sullivan Chief Operating Officer

Page 7 of 7 Pages Exhibit A AGREEMENT The undersigned, Forstmann-Leff Associates, LLC and FLA Advisers L.L.C. agree that the statement to which this exhibit is appended is filed on behalf of each of them. February 14, 2002 FORSTMANN-LEFF ASSOCIATES, LLC By: /s/ Joseph Sullivan Chief Operating Officer FLA ADVISERS L.L.C. By: /s/ Joseph Sullivan Chief Operating Officer