<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM STATEMENT OF
OPERATIONS AND BALANCE SHEET AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH 10-Q.
</LEGEND>
<MULTIPLIER>1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               JUN-30-1997
<CASH>                                          28,960
<SECURITIES>                                   132,868
<RECEIVABLES>                                    2,148
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                               163,976
<PP&E>                                          19,659
<DEPRECIATION>                                (10,670)
<TOTAL-ASSETS>                                 172,965
<CURRENT-LIABILITIES>                            4,800
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           181
<OTHER-SE>                                     167,984
<TOTAL-LIABILITY-AND-EQUITY>                   172,965
<SALES>                                              0
<TOTAL-REVENUES>                                 8,913
<CGS>                                                0
<TOTAL-COSTS>                                   15,834
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                (6,921)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                            (6,921)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (6,921)
<EPS-PRIMARY>                                    (.41)
<EPS-DILUTED>                                    (.41)