Asciminib (Scemblix) for Newly Diagnosed Chronic Myeloid Leukemia (CML)  

Asciminib (Scemblix) has been approved for adult patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) in chronic phase (CP). The accelerated approval was granted by the FDA on 29 October 2024.  

Earlier, asciminib was approved by FDA in October 2021 and by EMA in August 2022 for the treatment of adults with Ph+ CML in chronic phase (CML-CP), previously treated with ≥ 2 TKIs, and for the treatment of adults with Ph+ CML-CP with the T315I mutation.  

The drug was under clinical trial for evaluating its efficacy and safety in first line, later-line and paediatric patients with CML.  

The new approval for the newly diagnosed individuals with CML is based on efficacy and safety data from the trial. The efficacy of asciminib for newly diagnosed Ph+ CML in CP was evaluated in ASC4FIRST (NCT04971226) trial in which 405 patients were randomized (1:1) to receive either asciminib or investigator-selected tyrosine kinase inhibitors (IS-TKIs). The main efficacy outcome measure was major molecular response (MMR) rate at 48 weeks. The most common adverse reactions (≥20%) were musculoskeletal pain, rash, fatigue, upper respiratory tract infection, headache, abdominal pain, and diarrhea and the most common laboratory abnormalities (≥40%) in patients with newly diagnosed Ph+ CML in CP were decreased lymphocyte count, decreased leukocyte count, decreased platelet count, decreased neutrophil count, and decreased calcium corrected.  

Asciminib is a tyrosine kinase inhibitor (TKI). It inhibits ABL1 kinase activity of the BCR-ABL1 fusion protein which serves as a driver of CML proliferation in majority of individuals with CML. It binds at the myristoyl pocket of the BCR-ABL1 protein and locks it into an inactive conformation. 

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References:  

1. Press release – FDA grants accelerated approval to asciminib for newly diagnosed chronic myeloid leukemia. Posted 29 October 2024. Available at https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-asciminib-newly-diagnosed-chronic-myeloid-leukemia  

2. Deeks, E.D. Asciminib: First Approval. Drugs 82, 219–226 (2022). DOI:  https://doi.org/10.1007/s40265-021-01662-3  

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