Matching-Adjusted Indirect Comparison of Olutasidenib and Ivosidenib in Isocitrate Dehydrogenase 1-Mutated...

Olutasidenib and ivosidenib are isocitrate dehydrogenase 1 (IDH1) inhibitors approved for relapsed/refractory (R/R) IDH1 mutant (IDH1m) acute myeloid leukemia (AML).

A matching-adjusted indirect comparison estimated relative treatment effects using registrational Phase I/II data for olutasidenib (Study 2102-HEM-101; individual patient data) and ivosidenib (Study AG120-C-001; study-level data) since a head-to-head trial is unlikely. Weights were estimated using a logistic propensity score model adjusted for pre-defined covariates identified from a literature review, validated by clinical experts. Eight covariates were determined to be the most important prognostic factors/effect modifiers for the target population as reported in the Food and Drug Administration labels: number of prior systemic therapies, age, prior hematopoietic stem cell transplantation, AML type, relapse type, cytogenetic risk, Eastern Cooperative Oncology Group performance status, and IDH1 mutation.

Olutasidenib versus ivosidenib adjusted rates of complete remission (CR; odds ratio [OR] 1.12, 95% confidence interval [CI] 0.61-2.08), CR plus CR with partial hematologic recovery (CR + CRh; OR 0.83, 95% CI 0.46-1.50), and median CR duration (difference in medians 11.18 months, 95% CI - 4.30 to 22.72) were not significantly different. Median CR + CRh duration was significantly longer for olutasidenib (difference in medians 9.84 months, 95% CI 3.24-22.28), accompanied by a numerical non-significant trend in overall survival that should be considered exploratory (hazard ratio 0.75, 95% CI 0.53-1.07).

While not confirmatory, these findings may be clinically relevant in the context of this difficult-to-treat R/R IDH1m AML population.