<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   12-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1997             DEC-31-1996
<PERIOD-START>                             JAN-01-1998             JAN-01-1997             JAN-01-1996
<PERIOD-END>                               DEC-31-1998             DEC-31-1997             DEC-31-1996
<CASH>                                      33,091,000              57,830,000               8,611,000
<SECURITIES>                                         0                       0              38,300,000
<RECEIVABLES>                                2,450,000               4,235,000                       0
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                  2,389,000               2,227,000                       0
<CURRENT-ASSETS>                            38,772,000              65,214,000              47,259,000
<PP&E>                                      15,058,000              16,415,000               2,843,000
<DEPRECIATION>                               4,116,000                 951,000                 195,000
<TOTAL-ASSETS>                              87,601,000             121,947,000              51,692,000
<CURRENT-LIABILITIES>                        6,755,000               3,860,000               2,411,000
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                        68,000                  67,000                  54,000
<OTHER-SE>                                 182,538,000             182,539,000              46,156,000
<TOTAL-LIABILITY-AND-EQUITY>                81,601,000             121,947,000              51,692,000
<SALES>                                     13,443,000               5,002,000                       0
<TOTAL-REVENUES>                            13,443,000               5,002,000                       0
<CGS>                                        8,166,000               4,630,000                       0
<TOTAL-COSTS>                               44,500,000              62,057,000              21,734,000
<OTHER-EXPENSES>                           (6,296,000)             (5,441,000)             (1,874,000)
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                           2,036,000                 121,000                       0
<INCOME-PRETAX>                           (34,963,000)            (56,199,000)            (19,860,000)
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                                  0                       0                       0
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                              (34,963,000)            (56,199,000)            (19,860,000)
<EPS-PRIMARY>                                   (0.52)                  (1.01)                   (.50)
<EPS-DILUTED>                                   (0.58)                  (1.02)                   (.50)
        

</TABLE>