Cost-effectiveness of azacitidine and ivosidenib in newly diagnosed older, intensive chemotherapy-ineligible patients with IDH1-mutant acute myeloid leukemia.

Ivosidenib + azacitidine (IVO/AZA) is approved in the United States for newly diagnosed, older or intensive chemotherapy-ineligible patients with IDH1-mutated acute myeloid leukemia. We created a partitioned survival analysis model to evaluate the health economic implications of this approval. Model outputs were used to calculate the incremental cost-effectiveness ratio (ICER) of IVO/AZA versus AZA. One-way and probabilistic sensitivity analyses were conducted. In the base case scenario, IVO/AZA and AZA resulted in life-time costs of $403,062 and $161,887, respectively. With an incremental gain of 0.95 QALYs, the ICER of IVO/AZA was $252,782/QALY. In sensitivity analyses, only a reduction in the price of IVO by 59.3% lowered the ICER to below $150,000/QALY and 99.95% of model calculations yielded ICERs of >$150,000/QALY. In a model in which all patients received IVO monotherapy after progression on AZA monotherapy, the ICER was $155,453/QALY and various model inputs that would make IVO/AZA cost-effective were identified.