<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE FINANCIAL STATEMENTS OF ARONEX PHARMACEUTICALS, INC. SET FORTH IN THE COMPANY'S FORM 10-Q FOR THE THREE MONTHS ENDED JUNE 30, 2000 AND IS QUALIFIED IN ITS ENTIRE BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1 <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-END> JUN-30-2000 <CASH> 14,613,000 <SECURITIES> 2,468,000 <RECEIVABLES> 0 <ALLOWANCES> 0 <INVENTORY> 0 <CURRENT-ASSETS> 16,489,000 <PP&E> 5,559,000 <DEPRECIATION> 3,758,000 <TOTAL-ASSETS> 19,201,000 <CURRENT-LIABILITIES> 3,463,000 <BONDS> 0 <PREFERRED-MANDATORY> 26,000 <PREFERRED> 0 <COMMON> 0 <OTHER-SE> 12,347,000 <TOTAL-LIABILITY-AND-EQUITY> 19,201,000 <SALES> 0 <TOTAL-REVENUES> 286,000 <CGS> 0 <TOTAL-COSTS> 0 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 116,000 <INCOME-PRETAX> (4,466,000) <INCOME-TAX> 0 <INCOME-CONTINUING> (4,466,000) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (4,466,000) <EPS-BASIC> (0.18) <EPS-DILUTED> (0.18)