Clinical Trials

Geron Sponsored Trials

IMerge Phase 3  is closed to new patient enrollment. This study is designed to confirm the results from IMerge Phase 2 to support potential registration of imetelstat in lower risk MDS. IMerge Phase 3 is a double-blind, 2:1 randomized, placebo-controlled clinical trial and has been designed to enroll approximately 170 patients with lower risk MDS.  The trial will evaluate an improvement in the rate of red blood cell transfusion independence (RBC-TI) of participants treated with imetelstat compared to placebo. To be eligible for the trial, patients need to have non-del(5q) lower risk MDS, be transfusion dependent and have relapsed after or are resistant to treatment with erythroid stimulating agents (ESAs). Patients must also be naïve to treatment with hypomethylating agents (HMAs) and lenalidomide.


IMpactMF, our Phase 3 clinical trial in refractory MF, is open for screening and enrollment. The study is designed with registrational intent as an open label, 2:1 randomized, controlled clinical trial of imetelstat to evaluate a potential improvement in overall survival in approximately 320 patients compared to best available therapy. To be eligible for the trial, patients need to have Intermediate-2 or High-risk MF and also be non-responsive, or refractory, to treatment with a janus kinase (JAK) inhibitor.


IMproveMF is designed as a two-part Phase 1 clinical trial evaluating imetelstat in combination with ruxolitinib in patients with Intermediate-1, Intermediate-2 or High-risk frontline myelofibrosis. In Part 1 of the study, the objective is to identify the safe dose of the combination treatment. In Part 2 the objective is to confirm the dose of the combination treatment of imetelstat and ruxolitinib and evaluate efficacy. The study is expected to be open for patient enrollment in the first half of 2022.


Investigator Led Trials

IMpress is a Phase 2 clinical trial evaluating imetelstat as a single agent in patients with acute myeloid leukemia, or AML, or Intermediate-2 or High-risk myelodysplastic syndromes, or higher risk MDS, who are relapsed/refractory/intolerant to hypomethylating agents, or HMAs. The objective of this trial is to evaluate the efficacy of single agent imetelstat in this patient population and the primary endpoint of this trial is overall response rate. This study is expected to be open for patient enrollment in the second half of 2022.

TELOMERE is a Phase 1/2 clinical trial evaluating imetelstat in patients with relapsed/refractory acute myeloid leukemia, or AML. The trial is designed to test two distinct combinations of imetelstat and venetoclax  or imetelstat and azacitidine. The primary objective of the Phase 1 portion is to identify a safe dose of each of the combinations.  The primary objective of the Phase 2 portion of the study is overall response rate for each of the combination regimens. The planned start date for TELOMERE is pending IMpress single-agent imetelstat data. We expect such data to help inform the dose and schedule to be used in the two combination dosing regimens to be evaluated in TELOMERE.

To learn more about clinical trials, please visit To see clinical trials that are currently underway and to find out if a study is enrolling patients with your condition and in your area, please visit If you have any questions regarding ongoing clinical trials of imetelstat, please contact

Data from our completed Phase 2 clinical trials in lower risk MDS and relapsed/refractory MF are available at