Geron IMerge Phase 3 Presentations at Upcoming ASH Annual Meeting Reinforce Significant Durability and Breadth of Effect of Imetelstat in Lower Risk MDS - Seite 2

Abstract #194: “Efficacy of Imetelstat in Achieving Red Blood Cell Transfusion Independence (RBC-TI) Across Different Risk Subgroups in Patients with Lower Risk Myelodysplastic Syndromes (LR MDS) Relapsed/Refractory (R/R) to Erythropoiesis Stimulating Agents (ESAs) in IMerge Phase 3 Study”

Oral Presentation on December 9, 2023, at 2:15 p.m. PT

This abstract evaluates TI rates in patients treated with imetelstat vs. placebo across different risk subgroups as defined by International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R) or IPSS molecular (IPSS-M) risk profiles and shows that patients treated with imetelstat consistently had higher TI response rates than placebo regardless of risk classification. Further, in patients re-classified as high or very high risk using IPSS-M, TI response rates with imetelstat (and not placebo) were similar to TI response rates in lower risk subgroups. This analysis suggests imetelstat has clinical activity in lower risk MDS patients independent of risk categories.

Abstract #4603: “Impact of Mutational Status on Clinical Response to Imetelstat in Patients with Lower Risk Myelodysplastic Syndromes in the IMerge Phase 3 Study”

Poster Presentation on December 11, 2023, from 6-8 p.m. PT

This abstract evaluates the impact of MDS-associated mutations on clinical efficacy of imetelstat for the 165 of 178 patients for whom mutation data were available and shows that RBC-TI response rates in patients receiving imetelstat occurred regardless of the presence of baseline MDS associated mutations that have a poor prognosis (either specific mutations or multiple concurrent mutations). In patients with mutations associated with poor prognosis (TP53, ETV6, RUNX1, ASXL1, or EZH2), ≥8-week and ≥24-week, TI was observed in 31.8% and 9.1% of imetelstat-treated patients vs 0 on placebo. The 8-week TI rate for patients with 3 or more mutations was 55.6% with imetelstat compared to 14.3% with placebo. This analysis suggests clinical benefit of imetelstat across different molecularly defined subgroups and independent of the underlying molecular pattern.

Abstract #4605: “Durable Continuous Transfusion Independence (TI) With Imetelstat in IMerge Phase 3 for Patients with Heavily Transfused Non-Del(5q) Lower Risk Myelodysplastic Syndromes (LR MDS) Relapsed/Refractory (R/R) to or Ineligible for Erythropoiesis-Stimulating Agents (ESAs)”

Poster Presentation on December 11, 2023, from 6-8 p.m. PT

This abstract evaluates the 1-year TI responders in IMerge Phase 3, including 17.8% of imetelstat-treated patients (21/118; 95% CI, 11.4-25.9) and 1.7% of patients on placebo (1/60; 95% CI, 0-8.9). The median duration of TI for imetelstat ≥1-year TI responders was 123 weeks (95% CI, 80.4 to not evaluable); the median increase in hemoglobin during the longest TI interval was 5.18 g/dL (range, 2.67-13.76 g/dL) for the imetelstat group vs 1.67 g/dL for the placebo patient. Of the 18/21 imetelstat-treated 1-year TI responders for whom mutation data were available, 72.2% achieved ≥50% SF3B1 variant allele frequency (VAF) reduction, including 7 patients in whom there was complete elimination of MDS associated mutations. The abstract concludes that the long-term durable TI, robust increases in hemoglobin and meaningful reductions in mutational burden suggest imetelstat may have disease-modifying activity. Grade 3-4 thrombocytopenia and neutropenia occurred in 14 (67%) and 20 (95%) patients with ≥1-year TI, respectively, and the mean duration of grade 3/4 thrombocytopenia and neutropenia events was 2.25 and 1.78 weeks, respectively. 89% of grade 3/4 thrombocytopenia and 81% of grade 3/4 neutropenia was reduced to grade 1/2 within 4 weeks.