Clinical trials

In addition to our Phase 3 trial for JAK inhibitor relapsed/refractory myelofibrosis (MF), we are exploring imetelstat’s potential in additional indications, as a single agent and in combination with current standard of care therapies through early-stage clinical trials.

Geron sponsored trials

IMpactMF logo

IMpactMF, our pivotal Phase 3 clinical trial in JAK inhibitor relapsed/refractory MF, is an open label, 2:1 randomized, controlled clinical trial of imetelstat to evaluate a potential improvement in overall survival compared to best available therapy. The trial is expected to enroll approximately 320 patients with intermediate-2 or high-risk MF who are relapsed or refractory to treatment with a Janus associated kinase (JAK) inhibitor. IMpactMF is open for screening and enrollment.


IMproveMF logo

IMproveMF is a two-part Phase 1 clinical trial evaluating imetelstat in combination with ruxolitinib in patients with Intermediate-1, Intermediate-2 or high-risk frontline MF. In Part 1 of the study, the objective is to identify a 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 to evaluate efficacy. IMproveMF is open for screening and enrollment.


Investigator led trials


IMpress is a Phase 2 clinical trial evaluating imetelstat as a single agent in patients with acute myeloid leukemia (AML) or high-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. The primary endpoint of this trial is overall response rate. IMpress is open for screening and enrollment.


To learn more about cancer 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