<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   3-MOS                   9-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1998             DEC-31-1997             DEC-31-1998
<PERIOD-START>                             JUL-01-1997             JUL-01-1998             JAN-01-1997             JAN-01-1998
<PERIOD-END>                               SEP-30-1997             SEP-30-1998             SEP-30-1997             SEP-30-1998
<CASH>                                               0               9,545,406                       0                       0
<SECURITIES>                                         0              18,933,863                       0                       0
<RECEIVABLES>                                        0               1,412,741                       0                       0
<ALLOWANCES>                                         0                       0                       0                       0
<INVENTORY>                                          0               1,412,473                       0                       0
<CURRENT-ASSETS>                                     0              31,034,483                       0                       0
<PP&E>                                               0               7,310,876                       0                       0
<DEPRECIATION>                                       0               4,572,300                       0                       0
<TOTAL-ASSETS>                                       0              34,049,841                       0                       0
<CURRENT-LIABILITIES>                                0               6,330,349                       0                       0
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                             0                 133,412                       0                       0
<OTHER-SE>                                           0              26,242,891                       0                       0
<TOTAL-LIABILITY-AND-EQUITY>                         0              34,049,841                       0                       0
<SALES>                                              0                       0                       0                       0
<TOTAL-REVENUES>                             1,976,561               2,387,376              12,831,123               5,897,806
<CGS>                                                0                       0                       0                       0
<TOTAL-COSTS>                                        0               1,196,945                       0               2,748,508
<OTHER-EXPENSES>                             4,646,876               4,835,793              13,035,266              14,775,363
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                              38,881                  51,496                  80,921                 158,969
<INCOME-PRETAX>                            (2,440,214)             (3,273,910)                 445,830            (10,408,867)
<INCOME-TAX>                                         0                       0                       0                       0
<INCOME-CONTINUING>                        (2,440,214)             (3,273,910)                 445,830            (10,408,867)
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                               (2,440,214)             (3,273,910)                 445,830            (10,408,867)
<EPS-PRIMARY>                                    (.24)                   (.25)                     .04                   (.78)
<EPS-DILUTED>                                    (.24)                   (.25)                     .04                   (.78)
        

</TABLE>