[Pharmacological and clinical profile of asciminib hydrochloride, a novel first-in-class tyrosine kinase inhibitor specifically targeting ABL myristoyl pocket].

On March 28th, 2022, asciminib hydrochloride (Scemblix Tablets 20 ‍mg/40 ‍mg), the world's first tyrosine kinase inhibitor (TKI) specifically targeting the ABL myristoyl pocket (STAMP inhibitor), was approved for chronic myeloid leukemia (CML) resistant or intolerant to prior therapy. Asciminib specifically binds to the myristoyl pocket, an allosteric site of BCR::ABL1, and inhibits the ABL1 family molecules. In vitro and in vivo pharmacology studies demonstrated cell growth inhibition and antitumor effects of asciminib. The international phase I study for patients with chronic or accelerated phase CML investigated the maximum tolerated dose (MTD) and recommended dose for expansion (RDE) of asciminib monotherapy. However, the MTD was not reached, so and RDE was determined based on tolerability, safety, pharmacokinetics (PK) and preliminary efficacy data obtained by the time of the study. RDE was determined to be 40 ‍mg twice daily in chronic or accelerated phase CML without T315I mutation, and 200 ‍mg twice daily in chronic or accelerated phase CML with T315I mutation. The international phase III study for patients with chronic phase CML who were previously treated with ≥2 TKIs and resistant or intolerant to the recent treatment demonstrated the superiority of asciminib over bosutinib in achieving the primary endpoint of a major molecular response (MMR) at week 24. Regarding safety, the most common treatment-related adverse event in asciminib arm was thrombocytopenia, and others included neutropenia. Asciminib is expected to be a new treatment option for CML patients who have limited choices due to resistance or intolerance to previous therapies.