An Optogenetic Therapy Receives Benefits from FDA

November 11, 2014

An optogenetic gene therapy targeting retinitis pigmentosa (RP) has been given a significant boost thanks to receiving an orphan designation from the U.S. Food and Drug Administration (FDA). Granted to treatments for conditions affecting less than 200,000 people in the United States, the orphan status will provide RetroSense, the developer of the emerging treatment, with tax credits, seven years of marketing exclusivity and reductions in regulatory fees.

The company hopes to launch a safety-oriented clinical trial of the treatment, which is designed to restore vision in people blinded by RP, in 2015."We expect to learn a lot from this study and what level of vision we can restore,” says Sean Ainsworth, RetroSense’s chief executive officer. “That knowledge will help guide our development going forward. Based on pre-clinical data, we expect to provide ambulatory vision at a minimum.”

RetroSense's optogenetic therapy, known as RST-001, is designed to deliver copies of a light-sensitive gene known as channelrhodopsin-2 to ganglion cells in the retina. Research has shown that ganglion cells, which normally do not process light, survive after photoreceptors are lost. Photoreceptors are the retinal cells that normally provide vision, but die from inherited retinal diseases such as RP. 

In addition to restoring vision, RST-001 is designed to work regardless of the genetic mutation causing the vision loss. That means it has the potential to work for most forms of RP and other retinal conditions in which most or all photoreceptors are lost.

The Foundation Fighting Blindness provided early funding for the development of RetroSense’s treatment and participated in discussions about a possible clinical trial with the FDA. The Foundation also hosted a workshop in which research experts from around the world discussed the emergence of RST-001 and other optogenetic therapies for restoring vision. 

“Optogenetics is a relatively new approach. It didn’t come on our radar screen until three or four years ago,” says the Foundation’s chief research officer, Stephen Rose, Ph.D. “But RetroSense has done a nice job quickly moving its treatment toward a clinical trial. There’s still a lot to learn, but I am very excited about the promise it holds for restoring vision in people with advanced retinal disease.”

For more information about optogenetic projects, check out these Foundation Fighting Blindness posts:

Optogenetics: Seeing the Light in a Whole New Way

Foundation Funding Two New Optogenetics Projects at UC Berkeley

GenSight’s Optogenetic Therapy Advancing Toward Human Study