Geron offers reassurance on its ESC safety record

A little more than a week ago, the FDA created a stir when it put a clinical hold back on Geron's pioneering embryonic stem cell trial. Today, Geron offered some added insight into the concerns about the spinal injury therapy and what company researchers have been able to ascertain so far.

In previous animal studies of GRNOPC1 , says Geron, researchers have found a low frequency of "microscopic cysts in the regenerating injury site." But the cysts were non-proliferative and confined to the injury site. A recent animal study found a higher level of cysts, but researchers noted that they retained the same benign qualities. That's significant, as developers in the field have had to face fears that an embryonic stem cell therapy could ignite a tumor type called teratomas.

"We have submitted these data to the FDA and are in discussions with the agency to answer its questions and proceed with the clinical trial," said the company in a release.

"I believe that since the worst case scenario (teratomas) did not occur, investors are relieved," said Merriman Curhan Ford analyst Joseph Pantginis.

- check out the Geron release
- read the story from Reuters