Research Update

First Person Treated in Phase 1/2 Clinical Trial for Retinitis Pigmentosa

The first person has been treated in a Phase 1/2 clinical trial with an optogenetic treatment; which involves the use of light to alter cell activity, and in this case to restore vision lost due to advanced Retinitis Pigmentosa¹.

Instead of targeting light-sensitive photoreceptor cells which degenerate and die in many retinal dystrophies, researchers in this study are investigating the potential for improving visual function by delivering a gene into the retinal ganglion cells to produce a light-sensitive protein called channelrhodopsin. This is because retinal ganglion cells can survive long after the light-sensitive photoreceptor cells die and proposes an alternative strategy for treating people living with advanced Retinitis Pigmentosa.

In addition to the optogenetic treatment, this protocol also requires the individual to wear a device like a pair of glasses to generate impulses similar to that of the photoreceptor cells, which is sent through retinal ganglion cells and optic nerve to the brain. Bionic Sight, the company which has developed this technology, believes that by creating signals and code which is similar to the natural impulse created by the photoreceptor cells, visual function can be restored.

According to Dr. Sheila Nirenberg, Professor of Physiology and Biophysics at the Weill Medical College of Cornell University “A key issue for producing meaningful vision is to send signals to the brain that the brain can understand”. The optic nerve sends specific code to the brain to identify what is being perceived, such as a person’s face or objects. By delivering this information in a similar fashion using this technology, Dr. Nirenberg believes that “meaningful perceptions become possible”².

Although still in the early stages of testing, this is an exciting therapy as it indicates the potential to treat people with very low light perception irrespective of the gene responsible for causing the condition. This trial began in March 2020 at the Ophthalmic Consultants of Long Island, USA and expects to continue dosing participants in the second half of the year².

References:

1. Clinical Trials.gov: Available at https://clinicaltrials.gov/ct2/show/NCT04278131?term=bs01&cond=Retinitis+Pigmentosa&draw=2&rank=1. Accessed July 2020.
2. EyeWire News: Bionic Sight Doses First Patient in a Phase 1/2 Clinical Trial of a New Investigational Treatment for Retinitis Pigmentosa. Available at https://eyewire.news/articles/bionic-sight-llc-doses-first-patient-in-a-phase-1-2-clinical-trial-of-a-new-investigational-treatment-for-blindness-caused-by-retinitis-pigmentosa/. Accessed July 2020.