This is a Phase 2/3, multicenter study of imetelstat sodium in which 289 participants
were enrolled.
- Phase 2 is an open-label, single-arm design to assess the efficacy and safety of
imetelstat sodium. A total of 57 participants were enrolled in Phase 2, including
the expansion cohort.
- Phase 3 is a double-blind, randomized design to compare the efficacy of imetelstat
sodium with placebo. In the Phase 3 study, 178 participants were enrolled and
randomized in a 2:1 ratio to receive either imetelstat sodium or placebo,
respectively.
- In a separate Ventricular Repolarization (VR) Substudy (QTc Substudy), 54
participants were enrolled and randomized 2:1 to receive either imetelstat sodium or
placebo. If after a minimum of 2 treatment cycles in the VR substudy, a participant
has no significant change to packed red blood cell (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 sodium.
The Extension Phase was initiated at the end of the Phase 3 study (24 months after the
last participant was randomized in the Phase 3) and will continue until participants who
entered Phase 3 study participated in the study for up to 5 years from the first dose of
imetelstat sodium (including treatment and follow-up), or 3 years of post-treatment
follow-up from the last dose of study treatment, whichever occurs later, or until death,
withdrawal of consent, study termination, or until a participant is lost to follow-up.
Participants ongoing on imetelstat sodium and considered to be benefiting from treatment
per Investigator in the Phase 3 Study or Ventricular Repolarization Substudy, have the
option to continue receiving imetelstat sodium in the Extension Phase. Participants in
the follow-up phase for the Phase 3 study or Ventricular Repolarization Substudy have the
option to continue the follow-up in the Extension Phase.
The Phase 2, Phase 3, and VR Substudy all 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 Extension Phase of the study will consist of an extended treatment
phase and an extended follow-up phase which will continue until death, lost to follow-up,
withdrawal of consent, or the End of the Study (whichever occurs first).