A Phase 2 Study Evaluating Olutasidenib in Patients With IDH1-mutated Clonal Cytopenia of Undetermined Significance and Lower-risk Myelodysplastic/Syndromes/Chronic Myelomonocytic Leukemia.

Primary Objectives - To determine the response rate of olutasidenib monotherapy in patients with IDH1-mutated CCUS or lower-risk MDS/CMML Secondary Objectives * To evaluate the rates of transfusion independence, defined as the absence of transfusions over a period of at least 8 weeks * To ascertain the safety and tolerability of olutasidenib monotherapy in these participants populations * To determine survival and rates of leukemia transformation * To analyze reduction in IDH1 clone size Exploratory Objectives \- To investigate global gene expression profiles, DNA methylation profiles, and other potential prognostic markers to explore predictors of antitumor activity and/or resistance to treatment. OUTLINE: Patients receive olutasidenib orally (PO) twice daily (BID) on days 1-28 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients with CCUS receive up to 18 months of olutasidenib. Patients with lower-risk MDS/CMML can receive olutasidenib until disease progression or unacceptable toxicity. Additionally, patients undergo blood sample collection and bone marrow aspiration and biopsy on study. After completion of study treatment, patients are followed up every 3 months for up to 3 years.