Pooled safety analysis of pimitespib for the treatment of patients with advanced gastrointestinal stromal tumors

Pimitespib is an oral small molecule inhibitor of the α and β isoforms of heat shock protein 90 (HSP90). It’s approved in Japan for GIST that has progressed after chemotherapy and is undergoing phase I development for the treatment of solid tumors in the EU and the USA. This article summarizes the milestones in the development of pimitespib and characterizes its safety profile. Pooled data from 119 patients showed that adverse drug reactions (ADRs) were common (95.8%), primarily gastrointestinal (83.2%, often diarrhea) and ocular (21.8%, often night blindness). Most ADRs had a median onset within weeks and were found to be manageable and reversible, thus supporting pimitespib's use in patients with advanced GIST.