It’s a go: US federal officials have cleared the way for Geron’s first-of-a-kind clinical trial involving cells derived from human embryonic stem (ES) cells, the Menlo Park, California-based biotech company announced today.

The approval ends a nearly year-long hold on the company’s phase 1 study to treat people with mid-spine injuries with ES cells differentiated to form neural precursors called oligodendrocytes. The trial was given the go-ahead by the US Food and Drug Administration in January 2009, but halted seven months later after researchers discovered microscopic cysts at the injury site in the spinal cords of animals given the treatment. Geron says it has now completed further mouse studies and developed new assays to ensure the safety of the cellular therapy.

Geron’s shares shot up more than 10% today on the news.

Geron’s green light could be good news for Advanced Cell Technology, a stem cell company out of Santa Monica, California that hopes to be next in line to launch an ES cell-based therapeutic trial. The company announced this week that it submitted additional material in support of to its application — first filed in November — for a cell therapy to treat an inherited form of juvenile blindness called Stargardt’s Macular Dystrophy.