Orphan Designation Boosts Clinical Development of RP Stem Cell Therapy

September 11, 2013

ReNeuron, a stem-cell therapy development company in the United Kingdom, has been granted an orphan designation by the U.S. Food and Drug Administration (FDA) and the European Commission for its emerging retinitis pigmentosa (RP) treatment, known as ReN003. Given to potential treatments for rare conditions that are life-threatening or chronically debilitating, “orphan” status provides a company with development incentives, tax credits and market protections for therapy development.

The designation bolsters ReNeuron’s plan to launch a Phase I/II clinical trial for ReN003 in mid-2014. The company is partnering with the Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, to develop the treatment. According to Michael Young, Ph.D., a lead investigator on the project at Schepens, ReNeuron plans to initiate the study in the United States and later extend it to sites in Europe

The emerging treatment involves the transplantation of retinal progenitor cells, which are more mature than embryonic stem cells, but haven’t completely developed into photoreceptors, the cells in the retina that make vision possible.

Dr. Young believes the therapy will have a two-fold effect. “First, we have evidence from rat studies that the transplanted stem cells rescue photoreceptors, both rods and cones, and preserve vision,” he says. “Second, studies in pigs show that these transplanted cells actually become new photoreceptors. This opens the possibility that we may actually restore vision to those already blind.”

The initial priority of the study will be to demonstrate tolerability and safety with low therapy doses in older patients with substantial vision loss. If early safety goals are met, the study will evaluate higher doses in patients with better vision.

Dr. Young notes that the Foundation Fighting Blindness played a key role in the advancement of ReNeuron’s therapy. “FFB provided critical funding for earlier work on these cells to show that they can, in fact, differentiate into mature photoreceptors,” he says. The Foundation also plans to provide additional resources to ReNeuron in support of preparation for its ReN003 clinical trial.

In July, ReNeuron received approximately $50 million from investors for the funding of ReN003 and its two other stem-cell therapy programs: ReN001, which is in a clinical trial for stroke, and ReN009, which is nearing a clinical trial for chronic limb ischemia, a common and serious side effect of diabetes.

“ReNeuron is well-positioned to clinically advance its stem-cell therapy for people with RP,” says Brian Mansfield, Ph.D., deputy chief research officer, Foundation Fighting Blindness. “We are excited to learn more about its safety and potential for saving and restoring vision.”