Geron Corp., a biotechnology company with no marketed products, plunged the most ever after U.S. regulators halted development of its only experimental drug, imetelstat for blood disorders, because of the possibility of liver damage.
Geron sank 62 percent to $1.69 at the close in New York in its biggest decline since the company first sold shares to the public in 1996. Before today, the shares of the Menlo Park, California-based company had tripled in the last 12 months.
The U.S. Food and Drug Administration told Geron to place a clinical hold on its mid-stage trials of imetelstat because of low-grade liver function test abnormalities. The regulator cited the potential risk of chronic liver injury following long-term exposure to the drug, Geron said in a statement today.
“The FDA expressed concern about whether these LFT abnormalities are reversible,” the company said. “Geron plans to work diligently with the FDA to seek the release of the clinical hold.”
In November, Geron reported data showing imetelstat helped patients with myelofibrosis, a bone marrow disorder, sending the shares up the most in more than a decade. The clinical hold applies to studies in essential thrombocythemia, polycythemia vera and multiple myeloma. Geron said it’s likely that a planned mid-stage study in myelofibrosis will be delayed.
“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,” Charles Duncan, an analyst with Piper Jaffray, wrote in a research note today.
The company canceled its call to discuss fourth-quarter results this afternoon and said they will be reported in a regulatory filing, opting instead for a conference call this morning about the FDA action.