Study to Evaluate Imetelstat (GRN163L) in Subjects With International Prognostic Scoring System (IPSS) Low or Intermediate-1 Risk Myelodysplastic Syndrome (MDS)

Official Title

A Study to Evaluate Imetelstat (GRN163L) in Transfusion-Dependent Subjects With IPSS Low or Intermediate-1 Risk Myelodysplastic Syndrome (MDS) That is Relapsed/Refractory to Erythropoiesis-Stimulating Agent (ESA) Treatment


The purpose of this study is to evaluate the efficacy and safety of imetelstat in transfusion dependent participants with low or intermediate-1 risk myelodysplastic syndrome (MDS) that is relapsed/refractory to erythropoiesis-stimulating agent (ESA) treatment in Part 1 of the study and to compare the efficacy, in terms of red blood cell (RBC) transfusion independence (TI), of imetelstat to placebo in transfusion dependent participants with low or intermediate-1 risk MDS that is relapsed/refractory to ESA treatment in Part 2 of the study.

Trial Description

Primary Outcome:

  • Part 1 and Part 2 (Main Study): Percentage of Participants Without any Red Blood Cell (RBC) Transfusion During any Consecutive 8-Week Period
Secondary Outcome:
  • Number of Participants with Adverse Events (AEs)
  • Percentage of Participants Without any RBC Transfusion During any Consecutive 24-Week Period
  • Time to the 8-Week RBC Transfusion Independence (TI)
  • Duration of RBC TI
  • Percentage of Participants with Hematologic Improvement
  • Percentage of Participants with Complete Remission (CR) or Partial Remission (PR) as Per International Working Group (IWG) Response Criteria 2006
  • Overall Survival
  • Progression Free Survival (PFS)
  • Time to Progression to Acute Myeloid Leukemia
  • Amount of RBC Transfusions
  • Relative Change in RBC Transfusions
  • Percentage of Participants Receiving any Myeloid Growth Factors
  • Maximum Observed Plasma Concentration (Cmax)
  • Area Under the Drug Concentration-Plasma Time Curve From Time Zero to Last Measurable Concentration (AUC0-t)
  • Percentage of Participants with Antibodies to Imetelstat
  • Part 2 (Main Study): Medical Resource Utilization Data
  • Part 2 (Main Study): Assessment of Functional Assessment of Cancer Therapy-Anemia-Related Effects (FACT-An)
  • Part 2 (Main Study): Assessment of EuroQol 5 Dimension Questionnaire (EQ-5D-5L)
  • Part 2 (Main Study): Assessment of Quality of Life in Myelodysplasia Scale (QUALMS)
  • Part 2 (Main Study): Assessment of Participant Global Impression of Change (PGIC)
  • Part 2 (Ventricular Repolarization Substudy): Change in QT Interval by Fridericia's Correction Method
This is a Phase 2/3, multicentre study of imetelstat that consists of 2 parts and approximately 270 participants may be enrolled.

Part 1 is an open-label, single-arm design to assess the efficacy and safety of imetelstat. Approximately 55 participants were enrolled in Part 1, including the expansion cohort, and be followed-up for safety, hematologic improvement and reduction in transfusion requirement.

Part 2 is a double-blind, randomized design to compare the efficacy of imetelstat with placebo. In the main study in Part 2, 178 participants were enrolled and randomized in a 2:1 ratio to receive either imetelstat or placebo, respectively.

In a separate Ventricular Repolarization substudy of Part 2, approximately 45 participants will be enrolled and randomized 2:1 to receive either imetelstat or placebo. If after a minimum of 2 treatment cycles in the Ventricular Repolarization substudy, a participant has no significant change to pRBC transfusion burden or evidence of clinical benefit per Investigator, after discussion with the Sponsor the participant may be unblinded. If the participant was on placebo treatment, he/she may be permitted to start treatment with imetelstat.

Each part of the study will consist of 3 phases: a Screening phase (up to 28 days); a treatment phase; and a post-treatment follow-up phase which will continue until death, lost to follow-up, withdrawal of consent, or the End of the Study (whichever occurs first). The End of the Study is defined as 2 years after the study entry of the last participant in the main study of Part 2 or anytime the sponsor terminates the study, whichever comes first.

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