<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONDENSED BALANCE SHEET STATEMENTS OF OPERATIONS AND STATEMENTS OF CASH FLOWS
INCLUDED IN THE COMPANY'S FORM 10-Q FOR THE PERIOD ENDED JUNE 30, 1997 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS AND THE
NOTES THERETO.
</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>                                           7,144
<SECURITIES>                                    31,374
<RECEIVABLES>                                    5,941
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                                48,994
<PP&E>                                          21,481
<DEPRECIATION>                                (15,663)
<TOTAL-ASSETS>                                  54,812
<CURRENT-LIABILITIES>                           17,598
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                             2
<OTHER-SE>                                      34,322
<TOTAL-LIABILITY-AND-EQUITY>                    54,812
<SALES>                                              0
<TOTAL-REVENUES>                                12,905
<CGS>                                                0
<TOTAL-COSTS>                                        0
<OTHER-EXPENSES>                                30,442
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 348
<INCOME-PRETAX>                               (16,637)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                           (16,637)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                  (16,637)
<EPS-PRIMARY>                                   (0.83)
<EPS-DILUTED>                                   (0.83)