Asciminib

Asciminib is a tyrosine kinase inhibitor (TKI) used in the treatment of chronic-phase Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). More specifically, it is an inhibitor of the ABL1 kinase activity of the BCR-ABL1 fusion protein which serves as a driver of CML proliferation in most patients with the disease. It has also shown benefit in Ph+ CML with the T315I mutation, which produces a mutant BCR-ABL1 which is typically treatment-resistant as compared to wild-type BCR-ABL1. Existing inhibitors of ABL compete at the ATP binding sites of these proteins and can be classified into those that target the active conformation of the kinase domain ([dasatinib], [bosutinib]) and those that target the inactive kinase domain ([imatinib], [nilotinib], [ponatinib]). Asciminib is unique in that it acts as an allosteric inhibitor, binding at the myristoyl pocket of the BCR-ABL1 protein and locking it into an inactive conformation. Asciminib received FDA approval on October 29, 2021 (Scemblix, Novartis AG).