<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE COMPANY'S YEAR END REPORT ON FORM 10-K, FOR THE TWELVE MONTHS ENDED DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <CIK> 0000875320 <NAME> VERTEX PHARMACEUTICALS, INCORPORATED <MULTIPLIER> 1,000 <PERIOD-TYPE> YEAR <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-START> JAN-01-1999 <PERIOD-END> DEC-31-1999 <CASH> 31,548 <SECURITIES> 156,254 <RECEIVABLES> 5,956 <ALLOWANCES> 0 <INVENTORY> 0 <CURRENT-ASSETS> 195,197 <PP&E> 58,831 <DEPRECIATION> 34,351 <TOTAL-ASSETS> 232,445 <CURRENT-LIABILITIES> 18,518 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 257 <OTHER-SE> 208,977 <TOTAL-LIABILITY-AND-EQUITY> 232,445 <SALES> 8,053 <TOTAL-REVENUES> 61,648 <CGS> 2,925 <TOTAL-COSTS> 102,614 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 654 <INCOME-PRETAX> (40,966) <INCOME-TAX> 0 <INCOME-CONTINUING> (40,966) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (40,966) <EPS-BASIC> (1.61) <EPS-DILUTED> (1.61)