Clinical Trials

Geron is a late-stage clinical biopharmaceutical company focused on the development and potential commercialization of, an innovative therapeutic for hematologic myeloid malignancies. Geron’s vision is to be recognized as a leader in the treatment of hematologic malignancies. Geron is committed to improving and extending the lives of patients by changing the course of these diseases by targeting telomerase. We are currently focused on the development and potential commercialization of imetelstat, a first in class telomerase inhibitor, and are conducting two ongoing Phase 3 clinical trials that are intended to enable registration: (i) IMerge Phase 3 in Low or Intermediate-1 risk myelodysplastic syndromes, or lower risk MDS, and (ii) IMpactMF in Intermediate-2 or High-risk myelofibrosis, or refractory MF. 


IMerge Phase 3 is open for screening and enrollment and has been 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, randomized, placebo-controlled clinical trial and has been designed to enroll approximately 170 patients to 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 non-responsive, or refractory, to treatment with a janus kinase (JAK) inhibitor. 


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, including IMpactMF, please visit If you have any questions regarding ongoing clinical trials of imetelstat, please contact

Recent Phase 2 clinical data are available at