In what its chief executive called “a milestone for the field of human embryonic stem cell-based therapies”, Geron Corporation has finally launched a clinical trial in the US of GRNOPC1, its treatment for acute spinal cord injuries.

The first patient for the Phase I study has been enrolled at Shepherd Center, a spinal cord and brain injury rehabilitation hospital and clinical research centre in Atlanta, Georgia. Six more US sites may be involved in the trial, Geron said.

The main aim of the study is to assess the safety and tolerability of GRNOPC1 in patients with ‘complete’ American Spinal Injury Association Impairment Scale grade A thoracic spinal cord injuries. Participants must be newly injured and must be treated with GRNOPC1 within 14 days of the injury.

GRNOPC1 is Geron’s lead hESC-based therapeutic candidate and contains oligodendrocyte progenitor cells, derived from human embryonic stem cells, that have demonstrated remyelinating (the ability to regenerate a nerve’s myelin sheath) and nerve growth-stimulating properties, leading to restoration of function, in animal models of acute spinal cord injury.

“Initiating the GRNOPC1 clinical trial is a milestone for the field of human embryonic stem cell-based therapies,” commented Dr Thomas Okarma, president and chief executive officer of Geron. “When we started working with hESCs in 1999, many predicted that it would be a number of decades before a cell therapy would be approved for human clinical trials.”

Geron Corporation secured clearance from the US Food and Drug Administration in January 2009 for what the company said would be the world’s first study of a human embryonic stem cell (hESC)-based therapy in humans.

However, the FDA subsequently put Geron’s Investigational New Drug application for GRNOPC1 on clinical hold in August of the same year, pending its review of new non-clinical animal study data submitted by the company.

The trial approval was hailed not just as a breakthrough for clinical research but as the harbinger of a more accommodating US climate for stem cell research under the Obama administration.

President Obama did make good on his promise to scrap the executive order passed by former President George W Bush in August 2001, which severely limited federal backing for embryonic stem cell research by banning funding for projects that used anything other than the 22 or so embryonic stem cell lines then available for study.

Thrown into doubt

However, the research environment for hESC-based therapies has since been thrown into doubt again by a recent District Court ruling that federal funding of embryonic stem cell research violated a 1996 law – the so-called Dickey-Wicker Amendment – prohibiting the use of public money for research that involves the destruction of human embryos.

The US Justice Department has since filed a motion to have the preliminary injunction imposed by Judge Royce Lamberth suspended. Late last month, an appeals court in Washington put the injunction on hold while full arguments are heard in the case.

None of this affects Geron directly, as GRNOPC1 was based on ESC lines that predated the 2001 order, and the company did not apply for federal funding anyway.