<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED>

<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   YEAR                   9-MOS                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-START>                             JAN-01-1996             JAN-01-1996             JUL-01-1996
<PERIOD-END>                               DEC-31-1996             SEP-30-1996             SEP-30-1996
<CASH>                                       5,183,694              48,892,562              48,892,562
<SECURITIES>                                42,608,043              32,408,328              32,408,328
<RECEIVABLES>                                  247,981                 115,000                 115,000
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                    220,171                       0                       0
<CURRENT-ASSETS>                            49,330,057              81,591,374              81,591,374
<PP&E>                                       2,747,592               2,221,153               2,221,153
<DEPRECIATION>                               (252,785)               (116,159)               (116,159)
<TOTAL-ASSETS>                              83,691,369              84,732,610              84,732,610
<CURRENT-LIABILITIES>                        3,309,984               2,386,800               2,386,800
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                   102,053,375             103,195,187             103,195,187
<OTHER-SE>                                (22,799,515)            (20,849,377)            (20,849,377)
<TOTAL-LIABILITY-AND-EQUITY>                83,691,369              84,732,610              84,732,610
<SALES>                                        140,900                       0                       0
<TOTAL-REVENUES>                               140,900                       0                       0
<CGS>                                          842,330                       0                       0
<TOTAL-COSTS>                                  842,330                       0                       0
<OTHER-EXPENSES>                            18,452,347              13,151,978               5,414,789
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   0                       0                       0
<INCOME-PRETAX>                           (16,077,413)            (11,162,662)             (4,317,530)
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                       (16,077,413)            (11,162,662)             (4,317,530)
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                              (16,077,413)            (11,162,662)             (4,317,530)
<EPS-PRIMARY>                                   (1.64)                  (1.28)                  (0.33)
<EPS-DILUTED>                                   (1.64)                  (1.28)                  (0.33)


</TABLE>