The US Food and Drug Administration (FDA) has issued a full clinical hold for the telomerase inhibitor imetelstat, citing concerns that long-term exposure to the drug may pose a risk of chronic liver injury.
The hold temporarily suspends all ongoing clinical trials of imetelstat sponsored by the drug’s maker, Geron Corporation.
It’s possible that other studies of imetelstat, such as ongoing investigator-sponsored trials, may be placed on hold as well.
At present, the hold affects the remaining 8 patients enrolled on Geron’s phase 2 study of imetelstat in essential thrombocythemia and polycythemia vera.
It also affects the remaining 2 patients in the company’s phase 2 study of the drug in previously treated multiple myeloma. And Geron believes its planned phase 2 trial of imetelstat in myelofibrosis will likely be delayed as well.
The FDA has not yet issued a written notice of the hold but has given Geron verbal notice.
The agency indicated that the hold is due to persistent low-grade liver function test abnormalities observed in the study of imetelstat in patients with essential thrombocythemia or polycythemia vera and the potential risk of chronic liver injury following long-term exposure to imetelstat.
The FDA expressed concerns about whether these abnormalities are reversible. Geron said it plans to work with the FDA to put an end to the hold.
