ASCO 2021: Interim Analysis of Phase II Trial of Olutasidenib in IDH1-Mutant AML
Posted: Monday, June 7, 2021
Stéphane De Botton, MD, PhD, of Institut Gustave Roussy, Villejuif, France, and colleagues presented their interim analysis results of a phase II trial on the efficacy of the small-molecule inhibitor of mutant IDH1 olutasidenib in patients with IDH1-mutant acute myeloid leukemia (AML) at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 7006). They reported that olutasidenib was not only well tolerated, but it induced stable complete remission, achieved transfusion independence, and even reached a clinical benefit beyond that of patients in complete remission with partial hematologic recovery.
This study focused on 153 patients with relapsed or refractory IDH1-mutant AML who received 150 mg of olutasidenib twice daily. Complete remission with partial hematologic recovery was defined as an absolute neutrophil count of more than 0.5 × 109/L, a platelet count of more than 50 × 109/L, and less than 5% bone marrow blasts.
The median duration of treatment was 5.5 months, with 28% of patients remaining on olutasidenib monotherapy; others discontinued treatment due to disease progression (31%), adverse events (14%), death (10%), or transplant (8%). The researchers did not reach the median duration of complete remission with partial hematologic recovery; it was 13.8 months in a sensitivity analysis.
The overall response rate was 46%, with a median duration of 11.7 months. The 56-day platelet and red blood cell transfusion independence were achieved by 100% and 83%, respectively, in patients who reached complete remission with partial hematologic recovery; they were achieved by 56% and 50% in those who did not. The median overall survival was not reached, but the estimated 18-month overall survival was 87%.
Treatment-related adverse events such as nausea, constipation, and leukocytosis affected 38%, 25%, and 25% of participants, respectively. In addition, grade 3 to 4 events such as febrile neutropenia (20%), anemia (19%), thrombocytopenia (16%), and neutropenia (13%) were also observed.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.