Outcomes of Patients With IDH1-Mutated Myeloid Neoplasms Treated With Olutasidenib.

[BACKGROUND] IDH1 mutations correlate with poor prognosis in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), though this has evolved with targeted therapy. Olutasidenib, a selective oral IDH1 inhibitor, was approved for relapsed/refractory (R/R) AML in 2022.

[METHODS] We investigated a single-institution experience with olutasidenib regimens in IDH1-mutated AML and MDS.

[RESULTS] The study included 24 patients (19 AML, 5 MDS), with median age 75 years and 15 (62%) males. Fifteen patients (79%) had adverse-risk AML; 5 (100%) higher-risk MDS; and 9 (47%) secondary AML. The AML and MDS groups each included 2 previously untreated patients. The 17 R/R AML patients received a median of 3 prior therapies, including ivosidenib and/or venetoclax. Patients received olutasidenib monotherapy (n = 8) or combination therapy (n = 16). All 4 previously untreated patients responded. Overall response rates were 35% in R/R AML and 33% in R/R MDS. Two AML patients in complete remission remain on olutasidenib 5 to 7 years later, and 2 underwent allogeneic stem cell transplant. In the R/R patients, median overall survival was 3.3 months in AML and 14.0 months in MDS. Prior ivosidenib or venetoclax exposure did not impact survival.

[CONCLUSION] Olutasidenib-based therapy demonstrated 100% response rates in previously untreated IDH1-mutated AML and MDS and modest efficacy in heavily pretreated R/R AML and MDS. Durable remissions occurred in select responders and with stem cell transplant. Further evaluation of olutasidenib as frontline therapy in IDH1-mutated AML or MDS and as a bridge to transplant is warranted.