<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from the
condensed financial statements of AVANT Immunotherapeutics, Inc. for the Nine
Months Ended September 30, 1998 and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               SEP-30-1998
<CASH>                                       7,150,000
<SECURITIES>                                 7,865,300
<RECEIVABLES>                                   10,600
<ALLOWANCES>                                         0
<INVENTORY>                                      9,200
<CURRENT-ASSETS>                            16,317,800
<PP&E>                                       5,248,700
<DEPRECIATION>                             (4,182,700)
<TOTAL-ASSETS>                              25,146,500
<CURRENT-LIABILITIES>                        2,755,200
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        42,500
<OTHER-SE>                                  21,010,200
<TOTAL-LIABILITY-AND-EQUITY>                25,146,500
<SALES>                                         44,500
<TOTAL-REVENUES>                             1,082,200
<CGS>                                           20,500
<TOTAL-COSTS>                               51,085,400
<OTHER-EXPENSES>                             (184,200)
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                           (355,400)
<INCOME-PRETAX>                           (49,484,100)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                       (49,484,100)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                              (49,484,100)
<EPS-PRIMARY>                                   (1.65)
<EPS-DILUTED>                                   (1.65)