Geron shares blasted as FDA slams the brakes on imetelstat studies

Geron is back in the tank. The biotech's shares ($GERN) were in meltdown mode Wednesday morning, plunging more than 60% after the company announced that the FDA put its one and only drug imetelstat on a full clinical hold after detecting a risk of long-term liver damage following prolonged exposure to the treatment.

The move slams the brakes on a planned Phase II study of the drug for myelofibrosis as well as two ongoing studies for multiple myeloma and thrombocythemia. And it creates a crisis atmosphere for CEO John Scarlett, the former Proteolix chief who took on the task of running the company in the fall of 2011.

Evidence of liver toxicity is a key and potentially lethal threat for a host of experimental drugs. In this case, imetelstat represents the company's entire pipeline. According to the release, regulators are worried that the liver function test abnormalities seen may not be reversible. "Geron plans to work diligently with the FDA to seek the release of the clinical hold," the company said in a release.

The move comes just a few months after Geron got a big boost on the results of a small myelofibrosis study which boasted four cases with a complete remission, one partial remission and three patients demonstrating a clinical improvement--out of 18 patients in the study.

But setbacks are also well known at Geron, which has labored some 20 years at drug development without much success.

Back in 2012 the Menlo Park, CA-based biotech announced that GRN1005--in-licensed from Angiochem--was being jettisoned after investigators failed to see the kind of patient response they were looking for in a Phase II study for brain cancer. And without a pause executives announced they were terminating 43 of the company's 107 staffers in a move to conserve cash. Coming fast on the heels of a mid-stage failure for its other lead therapy, Geron shares crumbled yet again, even as it touted new signs of hope for its once-troubled program for imetelstat.

Earlier in 2012 Geron reported that big trouble developed for imetelstat, involved in a 166-patient study for metastatic HER2-negative breast cancer, as researchers found that the paclitaxel comparator arm was doing better than the lead drug. Geron was hoping that indications of success in imetelstat's Phase II would change its fortunes.

Geron had been best known for its work on developing new therapies from stem cells, but dumped the program in late 2011 after concluding that it couldn't continue to pay for the first in-human stem cell study. The company later sold the technology to BioTime.

- here's the release