<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM MAGAININ
PHARMACEUTICALS, INC. FORM 10K FOR THE YEAR ENDED DECEMBER 31, 1998 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1997
<PERIOD-START>                             JAN-01-1998             JAN-01-1997
<PERIOD-END>                               DEC-31-1998             DEC-31-1997
<CASH>                                           4,495                     487
<SECURITIES>                                    18,376                  38,574
<RECEIVABLES>                                        0                       0
<ALLOWANCES>                                         0                       0
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                23,050                  39,551
<PP&E>                                           6,240                   5,772
<DEPRECIATION>                                   3,475                   2,948
<TOTAL-ASSETS>                                  25,891                  42,444
<CURRENT-LIABILITIES>                           11,153                   6,478
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                            46                      44
<OTHER-SE>                                      14,634                  34,826
<TOTAL-LIABILITY-AND-EQUITY>                    25,891                  42,444
<SALES>                                              0                       0
<TOTAL-REVENUES>                                     0                  10,088
<CGS>                                                0                       0
<TOTAL-COSTS>                                        0                       0
<OTHER-EXPENSES>                                24,748                  26,121
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                 196                     118
<INCOME-PRETAX>                               (23,304)                (14,381)
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                           (23,304)                (14,381)
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                  (23,304)                (14,381)
<EPS-PRIMARY>                                   (1.05)                  (0.73)
<EPS-DILUTED>                                   (1.05)                  (0.73)
        

</TABLE>