Varespladib is an inhibitor of the IIa, V, and X isoforms of secretory phospholipase A2 (sPLA2).[1][2][3] The molecule acts as an anti-inflammatory agent by disrupting the first step of the arachidonic acid pathway of inflammation.[4] From 2006 to 2012, varespladib was under active investigation by Anthera Pharmaceuticals as a potential therapy for several inflammatory diseases, including acute coronary syndrome and acute chest syndrome.[5][6] The trial was halted in March 2012 due to inadequate efficacy.[7] The selective sPLA2 inhibitor varespladib (IC50 value 0.009 μM in chromogenic assay, mole fraction 7.3X10-6)[8] was studied in the VISTA-16 randomized clinical trial (clinicaltrials.gov Identifier: NCT01130246) and the results were published in 2014.[8] The sPLA2 inhibition by varespladib in this setting seemed to be potentially harmful, and thus not a useful strategy for reducing adverse cardiovascular outcomes from acute coronary syndrome. Since 2016, scientific research has focused on the use of Varespladib as an inhibitor of snake venom toxins[9][10][11][12][13] using various types of in vitro and in vivo models. Varespladib showed a significant inhibitory effect to snake venom PLA2 which makes it a potential first-line drug candidate in snakebite envenomation therapy. In 2019, the U.S. Food and Drug Administration (FDA) granted varespladib orphan drug status for its potential to treat snakebite.
^"Science: sPLA2". Anthera Pharmaceuticals. Retrieved 6 August 2011.
^Clinical trial number NCT01130246 for "VISTA-16 Trial: Evaluation of Safety and Efficacy of Short-term A-002 Treatment in Subjects With Acute Coronary Syndrome" at ClinicalTrials.gov