(r) pirtobrutinib

(R)-Pirtobrutinib ((R)-LOXO-305) is the less active enantiomer of Pirtobrutinib, a highly selective, non-covalent, next-generation BTK inhibitor that effectively inhibits diverse BTK C481 substitution mutations [1].

Pirtobrutinib (LOXO-305) is an advanced BTK inhibitor that displays high selectivity and operates through a non-covalent mechanism. This compound effectively inhibits various BTK C481 substitution mutations, leading to tumor regression in BTK-dependent lymphoma tumors in mouse xenograft models. Furthermore, Pirtobrutinib exhibits remarkable selectivity for BTK, with more than a 300-fold difference compared to 370 other kinases tested. Notably, at a concentration of 1 μM, Pirtobrutinib demonstrates no significant inhibition of non-kinase off-targets.