<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM JUNE 30,
2000 FORM 10-Q/A AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 11,815,671
<SECURITIES> 29,902,862
<RECEIVABLES> 0
<ALLOWANCES> 0
<INVENTORY> 0
<CURRENT-ASSETS> 42,546,619
<PP&E> 16,636,830
<DEPRECIATION> 12,395,847
<TOTAL-ASSETS> 81,075,462
<CURRENT-LIABILITIES> 8,191,958
<BONDS> 0
0
1,510,280
<COMMON> 233,465,928
<OTHER-SE> (163,990,137)
<TOTAL-LIABILITY-AND-EQUITY> 81,075,462
<SALES> 0
<TOTAL-REVENUES> 0
<CGS> 0
<TOTAL-COSTS> 23,746,645
<OTHER-EXPENSES> 0
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 369,086
<INCOME-PRETAX> (23,153,705)
<INCOME-TAX> 0
<INCOME-CONTINUING> 0
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (23,153,705)
<EPS-BASIC> (1.05)
<EPS-DILUTED> (1.05)
</TABLE>