The U.S. Food and Drug Administration (FDA) has granted approval to Scemblix (asciminib) for the first-line treatment of adult patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (Ph+ CML-CP). This decision expands the drug's indication, offering a new therapeutic option for patients newly diagnosed with CML.
The approval is based on data from the pivotal ASCEMBL trial, a Phase III, randomized, open-label study. The trial evaluated the efficacy and safety of Scemblix compared to a tyrosine kinase inhibitor (TKI) in patients with CML-CP who had failed two or more prior TKIs. Results demonstrated a significantly higher major molecular response (MMR) rate at 24 weeks with Scemblix compared to bosutinib (25.5% vs. 13.2%, P=0.029).
Scemblix is a STAMP inhibitor that specifically targets the ABL myristoyl pocket (also known as an allosteric inhibitor). It works by binding to the ABL myristoyl pocket, inhibiting the BCR-ABL1 protein's activity and blocking the signaling pathways that drive CML cell growth. This mechanism of action differs from traditional TKIs, which bind to the ATP-binding site of the BCR-ABL1 kinase.
This approval marks a significant advancement in the treatment landscape for CML, providing a novel approach to targeting the disease. Scemblix offers an alternative for patients who may have developed resistance or intolerance to existing TKI therapies.
