- Monotherapy with the MEK 1/2 inhibitor binimetinib demonstrated acceptable tolerability but minimal efficacy in patients with relapsed or refractory acute myeloid leukemia (R/R AML).
- Binimetinib may be better studied in combination with synergistic therapies in future studies.
Why this matters
- Other MEK inhibitors, selumetinib and trametinib, have demonstrated modest monotherapy efficacy in this setting.
- Phase 2 study to investigate binimetinib in 19 patients with R/R AML, 14 of whom had RAS mutations.
- 64 (range, 31-85) years median patient age.
- Patients had received a median of 3 (range, 1-6) prior lines of therapy.
- Funding: National Cancer Institute.
- 8% (1 of 13 evaluable patients) who had a NRAS G12A mutation achieved complete response with incomplete blood count recovery for a duration of 2.1 months.
- 92% of patients did not respond to treatment.
- 1.8 months median OS; 42% OS at 3 months, 12% OS at 6 months.
- The most common grade 3/4 treatment-related adverse events (TRAEs) were hypokalemia (6%), hypotension (6%), lung infections (6%), and febrile neutropenia (6%).
- Open-label study.
- Limited sample size.