<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONDENSED CONSOLIDATED BALANCE SHEETS AND CONDENSED CONSOLIDATED STATEMENTS OF
OPERATIONS FOUND ON PAGES 3 AND 4 OF THE COMPANY'S FORM 10-K AND FORMS 10-Q
FOR THE YEAR AND YEAR-TO-DATE, RESPECTIVELY, AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   YEAR                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-END>                               DEC-31-1996             JUN-30-1996             SEP-30-1996
<CASH>                                          33,445                  43,454                  14,257
<SECURITIES>                                    56,407                  70,280                  88,778
<RECEIVABLES>                                      583                       0                       0
<ALLOWANCES>                                        33                       0                       0
<INVENTORY>                                      2,107                       0                       0
<CURRENT-ASSETS>                                94,226                 114,950                 105,241
<PP&E>                                           7,979                   3,769                   5,971
<DEPRECIATION>                                   1,584                     822                   1,096
<TOTAL-ASSETS>                                 101,852                 118,076                 110,321
<CURRENT-LIABILITIES>                            6,665                   2,886                   4,870
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                            24                      24                      24
<OTHER-SE>                                      90,446                 110,440                 100,813
<TOTAL-LIABILITY-AND-EQUITY>                   101,852                 118,076                 110,321
<SALES>                                            624                       0                       0
<TOTAL-REVENUES>                                   624                       0                       0
<CGS>                                              561                       0                       0
<TOTAL-COSTS>                                      561                       0                       0
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                    33                       0                       0
<INTEREST-EXPENSE>                                 592                     224                     344
<INCOME-PRETAX>                               (34,054)                 (9,699)                (23,135)
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                           (34,054)                 (9,699)                (23,135)
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                  (34,054)                 (9,699)                (23,135)
<EPS-PRIMARY>                                   (1.79)                  (0.58)                  (1.27)
<EPS-DILUTED>                                   (1.79)                  (0.58)                  (1.27)


</TABLE>