Asciminib in Chronic Myeloid Leukemia after ABL Kinase Inhibitor Failure

Area of Science:

• Oncology
• Hematology
• Pharmacology

Background:

• Asciminib is a novel allosteric inhibitor targeting the BCR-ABL1 myristoyl site, distinct from other ABL kinase inhibitors.
• It effectively targets native and mutated BCR-ABL1, including the T315I mutation.
• The safety and efficacy of asciminib in Philadelphia chromosome-positive leukemia were previously unknown.

Purpose of the Study:

• To evaluate the safety and antileukemic activity of asciminib in patients with Philadelphia chromosome-positive leukemia.
• Determine the maximum tolerated dose (MTD) or recommended dose (RD) of asciminib.
• Assess asciminib's efficacy in heavily pretreated patients with resistance or intolerance to prior tyrosine kinase inhibitors (TKIs).

Main Methods:

• Phase 1, dose-escalation study of asciminib in 150 patients with chronic myeloid leukemia (CML).
• Patients had resistance or unacceptable side effects from at least two prior ATP-competitive TKIs.
• Asciminib was administered at doses ranging from 10 to 200 mg once or twice daily, with a median follow-up of 14 months.

Main Results:

• Asciminib was active in heavily pretreated CML patients, with 92% achieving complete hematologic response and 54% achieving complete cytogenetic response.
• A major molecular response (MMR) was achieved or maintained by 12 months in 48% of evaluable patients.
• Responses were durable, and asciminib showed efficacy in patients resistant to ponatinib and those with the T315I mutation.

Conclusions:

• Asciminib is active and well-tolerated in CML patients with resistance or intolerance to prior TKIs.
• It demonstrates significant efficacy, including in challenging patient populations like those with the T315I mutation.
• Asciminib represents a promising therapeutic option for patients with Philadelphia chromosome-positive leukemia who have exhausted other treatment options.