Geron Corporation announced Monday it will discontinue its stem cell programs due to high costs.

California- based Geron was carrying out the first U.S. trial with human embryonic stem cells aimed at treating paralysis. As of October 20, the company had enrolled four patients in embryonic stem cell therapy during the Phase I trial. So far, the therapy had been well tolerated with no serious adverse events, the company said.

"Geron plans to close the GRNOPC1 [human embryonic stem cell-based therapy] trial for spinal cord injury to further enrollment, although it will continue to follow all enrolled patients, accruing data and updating FDA and the medical community on their progress," the company said in a statement yesterday.

Geron said it is seeking partners to enable further development of its stem cell programs.

"Stem cells continue to hold great medical promise. We believe that our leadership role in the field and the quality of our stem cell assets-which are widely recognized as being among the most innovative, comprehensive and advanced cell therapy programs in the world-will be an important point of differentiation in our discussions to partner these assets," Geron's Chief Executive Officer, John A. Scarlett, M.D. said in a statement.

The clinical trial aimed to administer a dose of 2 million stem cells in up to 10 patients with neurologically complete injuries in the thoracic region of the spinal cord.

Geron also said it is eliminating 66 full-time positions or 38 percent of its workforce and will focus on the clinical trials of two cancer drugs. Stem cells have the potential to develop into many different cell types in the body and are used to repair and regenerate diseased organs and tissue.

Stem cells from human embryos are removed at the embryo's blastocyst stage or before they are implanted in the womb when it consists of around 80 to 100 cells.