Rigel Pharmaceuticals’ olutasidenib shows efficacy in Phase 2 AML trial

Rigel Pharmaceuticals (RIGL) announced a peer-reviewed publication in the Journal of Hematology & Oncology of the final five-year data from the pivotal cohort of the Phase 2 registrational trial evaluating Rezlidhia, or olutasidenib, for the treatment of patients with relapsed or refractory mutant isocitrate dehydrogenase-1 – mIDH1 – acute myeloid leukemia, or AML. Rezlidhia is a small-molecule inhibitor of mIDH11 approved for the treatment of R/R mIDH1 AML. The publication reports the final follow-up analysis of the registrational Phase 2 trial, with an additional two years of efficacy and safety data. These five-year data further support the durable responses and manageable safety profile observed with olutasidenib in patients with R/R mIDH1 AML, including those R/R to prior venetoclax. The safety profile remained consistent with what was previously reported, with no new safety signals identified. The five-year safety profile of olutasidenib remained consistent, with no new safety signals identified vs. the three-year analysis, and no new cases of differentiation syndrome reported. Of 147 efficacy evaluable patients, complete remission – CR – with partial hematologic recovery was achieved in 35%. Median duration of CR/CRh was 25.3 months. Overall response rate, or ORR, was 48%, with median duration of 15.5 months. Median overall survival was 11.5 months. Among the 71 patients who achieved an overall response, 66% of patients achieved a response within 2 months, 24% required 2 to 4 months to respond and 10% required at least 4.6 months. Rigel is also evaluating olutasidenib in other disease areas where mIDH1 plays a role.