US FDA Grants RMAT Designation for Bionic Sight’s RP Gene Therapy Candidate

Bionic Sight announced Feb. 18 that the US FDA had granted regenerative medicine advanced therapy (RMAT) designation to BS01, the company’s gene therapy candidate targeting retinitis pigmentosa (RP).

The RMAT designation, established under the 21st Century Cures Act, allows companies developing regenerative medicine and gene therapies to work more closely and frequently with the FDA, and grants all the benefits of breakthrough therapy designation, including eligibility for priority review, rolling review, and accelerated approval.

Bionic Sight’s approach involves two components:

—A one-time optogenetic treatment that enables expression of a light-sensitive protein in retinal ganglion cells which survive after photoreceptors are lost due to an advanced retinal disease such as RP.

—A device, worn like a pair of glasses, that captures the scene a person is looking at and generates vision-enabling code, which is sent to the light-sensitive ganglion cells, and then on to the brain.

Bionic Sight, of New York, has reported preliminary data from a Phase I/II trial of several dose levels of BS01 in subjects who are nearly blind from RP.

Participants who received the lower doses showed a modest but consistent improvement: Five of five showed an increase in light sensitivity of 100-fold or more, and several also gained the ability to detect motion.

Participants who received the two highest doses showed a much more marked improvement. Ten of 11 showed an increase in best-corrected visual acuity (BCVA), with seven patients showing an average increase of nearly five lines on an EDTRS eye chart.

Bionic Sight said the gain was seen across a spectrum of patients—from those whose baseline vision was at the “count fingers” level to those whose baseline was at “tunnel vision” (less than 10 degrees of visual field). 

In addition to the increase in BCVA, the “count fingers” patients gained the ability to recognize shapes, objects, and, in some cases, colors, Bionic Sight said, and the “tunnel vision” patients showed both an increase in visual field size (a three-fold increase in area) and a pronounced improvement in their ability to navigate a maze (measured as a reduction in the time to complete the maze and a reduction in the number of errors).

The company said it is readying its Phase III program.