Restoring Sight: First In-Human Test Of Optogenetics

Michigan-based startup RetroSense Therapeutics, plans to be the company to sponsor a clinical trial of optogenetics in human patients. The technology – which was originally developed by neuroscientists – combines gene therapy and precision light to stimulate nerve cells.

Doctors at the Retina Foundation of the Southwest plan on conducting the clinical trial, which could recruit up to 15 patients with retinitis pigmentosa to test the optogenetics technique. Retinitis pigmentosa is a degenerative disease characterized by the death of photoreceptor cells in the eye, eventually leading to blindness.

The researchers hope that the optogenetics therapy will be successful in converting another retinal cell type – known as ganglion cells – in light receptors capable of partially replacing the non-functional photoreceptor cells. Other researchers believe optogenetics may have an application in the treatment of neurologic conditions including Parkinson’s disease, and even mental illness.

Researchers plan to follow the upcoming study of optogenetics very closely, in order to assess its potential to treat other diseases. “This is going to be a gold mine of information about doing optogenetics studies in humans,” said Antonello Bonci, scientific director of the intramural research program at the National Institute on Drug Abuse in Baltimore.

While the patients taking part in the optogenetics study will likely have an advanced form of retinitis pigmentosa, according to RetroSense CEO Sean Ainsworth, the hope is that these patients will be able read large letters after receiving the treatment. The optogenetics technique applied by RetroSense uses gene therapy to introduce the DNA sequence for channelrhodopsin – a light-sensitive protein from algae – into ganglion cells to allow them to react when exposed to a specific wavelength of light.

The researchers are optimistic that the technique could produce at least 100,000 light-sensitive ganglion cells in the retina. As there are very few therapeutic options for patients with retinitis pigmentosa, these cells could help restore a substantial level of vision.

The technique, however, does present some limitations. The algal channelrhodopsin protein is only sensitive to blue light, leading RetroSense researchers to believe the patients may only regain monochromatic vision. The optogenetics clinical trial is expected to commence next month.