By: Kerri Fitzgerald
A post-hoc analysis of pooled data from the IMerge trial found that patients with low-risk myelodysplastic syndromes (MDS) who were ineligible for erythropoiesis-stimulating agents (ESAs) due to elevated baseline serum erythropoietin derived clinical benefit from frontline treatment with imetelstat.
Rami Komrokji, MD, of the H. Lee Moffitt Cancer Center in Tampa, Florida, presented the results at the 2025 EHA Congress.
Researchers used data from the phase 2, phase 3, and QTc substudy results from IMerge, which treated adults with imetelstat 7.1 mg/kg or placebo, both administered as a two-hour intravenous infusion every 4 weeks.
They studied treatment outcomes in patients based on baseline serum erythropoietin level:
- 13 patients were treatment-naïve and had serum erythropoietin >500 mU/mL
- 112 patients previously received ESAs and had serum erythropoietin <200 mU/mL
- 43 patients previously received ESAs and had serum erythropoietin between 200 and ≤500 mU/mL
- 42 patients previously received ESAs and had a serum erythropoietin >500 mU/mL
Among the treatment-naïve cohort, median age was 71 years, and patients had a median transfusion burden of 6 units of red blood cell every 8 weeks. More than a third (38%) had intermediate-1 International Prognostic Scoring System disease, and 85% had ring sideroblast-negative status.
The median duration of imetelstat treatment-naïve patients was 52 weeks. At different time points assessed, the following percentage of patients achieved red blood cell transfusion independence with imetelstat:
- 54% at ≥8 weeks
- 23% at ≥24 weeks
- 15% at ≥1 year
Red blood cell transfusion independence rates for other cohorts studied were:
- Patients with prior ESA use and serum erythropoietin <200 mU/mL
- 50% at ≥8 weeks
- 38% at ≥24 weeks
- 24% at ≥1 year
- Patients with prior ESA use and serum erythropoietin between 200 and ≤500 mU/mL
- 33% at ≥8 weeks
- 28% at ≥24 weeks
- 19% at ≥1 year
- Patients with prior ESA and serum erythropoietin >500 mU/mL
- 24% at ≥8 weeks
- 14% at ≥24 weeks
- 10% at ≥1 year
The percentage of patients achieving hematologic improvement-erythroid per the International Working Group 2006 criteria was 69%, 71%, 58%, and 60%, respectively, based on serum erythropoietin levels.
“These findings support the use of imetelstat in the frontline setting in patients with [low-risk] MDS who are ineligible for ESAs, and further support use in these patients after ESA therapy regardless of baseline [serum erythropoietin],” the authors concluded.
The study is supported by Geron Corporation.
Reference
Komrokji RS, Savona M, Santini V, et al. Outcomes with imetelstat by serum erythropoietin levels in patients with lower-risk myelodysplastic syndromes who were treatment naïve or who had prior treatment with erythropoiesis-stimulating agents. Abstract #PS1640. Presented at the European Hematology Association 2025 Congress; June 12-15, 2025; Milan, Italy.
