A study found that baseline platelet count, ASXL1 mutation, and Revised International Prognostic Scoring System (IPSS-R) status were the most important predictors of response to imetelstat in patients with lower-risk myelodysplastic syndromes (LR-MDS).
Rami Komrokji, MD, of the Moffitt Cancer Center in Tampa, Florida, and colleagues presented the findings at the 2026 SOHO Annual Meeting.
The study included 40 patients with LR-MDS treated with imetelstat between July 2024 and October 2025. The median age at diagnosis was 69.5 years, most were White (n=38), and more than half (n=23) were male.
Patients had the following mutation profile: SF3B1 (80.0%), TET2 (30.0%), and ASXL1 (27.5%). Mean hemoglobin was 7.4 g/dL, and most patients (75%) had low/moderate-low risk disease per the IPSS-R. Patients had received a mean of 8.5 prior red blood cell (RBC) transfusion units per 16 weeks.
Imetelstat was used in later lines of therapy (median, third-line use), and prior therapies included luspatercept (n=35; 87.5%), erythropoiesis-stimulating agents (n=28; 70%), hypomethylating agents (HMAs; n=15; 37.5%), and lenalidomide (n=17; 42.5%).
The best response, defined as RBC transfusion independence for more than eight weeks, was 37.5%, the median duration of response was 185 days, and the median time between cycles was 31 days. Baseline erythropoietin level, transfusion burden, and SF3B1 mutation did not predict treatment response.
Patients with ASXL1 mutations (n=9) were more likely to respond than those with wild-type (66.7% vs 29.0%; P=0.04). Baseline platelet count of ≥192×109/L was the best univariable predictor of response (odds ratio, 7.0).
Patients previously treated with HMAs (26.7% vs 44.0%, P=0.27) or lenalidomide (23.0% vs 28.0%, P=0.11) had a trend toward inferior response, while those receiving imetelstat within the first three lines of therapy (44.0% vs 26.7%, P=0.27) had a trend toward superior response.
Median overall survival from the start of imetelstat therapy was 17.3 months.
Grade 3/4 neutropenia occurred in 14 patients (35%) after cycle one and nine patients (22.5%) after cycle two. Grade 3/4 thrombocytopenia was observed in 11 patients (27.5%) after cycle one and in eight patients (20%) after cycle two. No patients experienced febrile neutropenia; five patients (12.5%) required platelet transfusion and four (10.0%) required granulocyte colony-stimulating factor.
Reference
Komrokji R, Al Ali N, Patra C, et al. Real-world outcomes of imetelstat: interrogating safety, efficacy, and predictors of response in heavily pretreated lower-risk patients with MDS. Abstract MDS-646. Presented at the 2026 Society of Hematologic Oncology Annual Meeting; September 9-12, 2026; Houston.
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