* FDA orders halt on concerns about liver damage
* Geron to give data on whether abnormalities reversible
* Shares fall as much as 68 pct
(Adds analyst comment, conference call details; updates shares)
March 12 Geron Corp said the U.S. Food
and Drug Administration ordered to halt trials of its only
remaining drug over concerns about liver damage, wiping out
about two-thirds of the company's value.
The cancer treatment, imetelstat, was touted as Geron's
savior after the company said in November that the drug had
completely cured 22 percent of myelofibrosis patients in a
Geron, which was once one of the leading firms in the race
to develop the first commercial stem-cell therapy, divested its
stem-cell assets last year after multiple disappointments to
focus on the development of the cancer treatment.
The halt, verbally notified by the FDA, will affect all
trials of the treatment, including the thrombocythemia and
multiple myeloma mid-stage studies, Geron said.
Geron is working with the FDA to provide data on whether the
liver function abnormalities found in the studies were
reversible, the company said on a conference call.
The treatment's tolerability was called into question in
January after enrollment was stopped in an early-stage trial
evaluating imetelstat's use in a rare blood disorder, and about
20 out of 79 patients dropped out.
Geron did not then disclose why the patients dropped out,
but said it would continue the study.
The company had earlier discontinued testing the drug for
use in breast and lung cancer after trial failures.
The FDA's decision bodes well for Incyte Corp,
whose drug Jakafi is approved to treat myelofibrosis. The drug
generated sales of $235.4 million in 2013.
Imetelstat's safety signal did not come as a surprise, UBS
analyst Roden said, as he had noted that imetelstat data had
showed significant toxicity.
However, analysts said the drug's ability to evoke a
disease-modifying effect, defined as partial or complete
remission, suggests it would be superior to Jakafi.
Imetelstat is designed to inhibit telomerase, an enzyme that
enables the rapid multiplication of tumor cells.
"We continue to believe imetelstat is efficacious and
disease modifying in myelofibrosis. However, we would remain on
the sidelines at this time as Geron has no pipeline to fall back
on should the FDA decide that imetelstat is simply unsafe,"
Piper Jaffray analyst Charles Duncan said.
Abnormalities in liver function has doomed other drugs,
including Gilead Sciences Inc's experimental hepatitis
C treatment, codenamed PSI-938.
Menlo Park, California-based Geron's stock was down nearly
64 percent at $1.61 in late-morning trade.
(Reporting by Natalie Grover and Chris Peters in Bangalore;
Editing by Gopakumar Warrier and Sriraj Kalluvila)