LY315920

LY315920 (Varespladib) is a potent and selective secretory phospholipase A2 (sPLA) inhibitor with IC50 of 7 nM. LY315920 inhibited sPLA2 activity with an IC50 of 9 +/- 1 nM or 7.3 x 10(-6) mole fraction, which approached the stiochiometric limit of this assay in a chromogenic isolated enzyme assay. LY315920 (Varespladib) was 40-fold less active against human, group IB, pancreatic sPLA2 and was inactive against cytosolic PLA2 and the constitutive and inducible forms of cyclooxygenase. The i.v. administration of LY315920, 5 min before harvesting the bronchoalveolar lavage cells, resulted in the inhibition of sPLA2-induced production of TXA2 with an ED50 of 16.1 mg/kg. LY315920 (Varespladib) is currently undergoing clinical evaluation and should help to define the role of sPLA2 in various inflammatory disease states.