&NA;Fradafiban (BIBU 52, BIBU 52 ZW) is a nonpeptide fibrinogen antagonist that is undergoing phase I/IIa trials with Boehringer Ingelheim Pharma KG in Europe. The orally active prodrug of fradafiban is lefradafiban. Other compounds in the same series of nonpeptide fibrinogen antagonists include BIBW 98.