The FDA has delayed approval of an application for the first human embryonic stem cell clinical trial by Geron Corporation, the company announced yesterday.

Geron's compound, GRNOPC1, is a cell-based therapy to treat spinal cord injury. Yesterday, the FDA told Geron verbally that they were placing the Investigational New Drug submission of the treatment under a clinical hold. The company is awaiting a formal letter.

Thomas Okarma, Geron's president and chief executive officer, said in a press release: "We are disappointed with this action given the interactions we had with the FDA over four years leading to the filing, and the breadth and depth of the submission, some 21,000 pages, predicated on those discussions with the agency."

Ren Benjamin, an analyst with Rodman & Renshaw, told Bloomberg News that the FDA's decision was not surprising. The agency held a meeting last month to consider what guidelines to recommend for sponsors developing human embryonic stem cell-based therapies. Celia Witton, spokesperson for the FDA, said at that meeting that the agency had to process a tremendous amount of information before they can decide how to properly regulate trials for new therapies.