GenSight Biologics’ Optogenetic Treatment Results in 57% Increase in Visual Recovery of Patient with Retinitis Pigmentosa

GenSight Biologics’ Optogenetic Treatment Results in 57% Increase in Visual Recovery of Patient with Retinitis Pigmentosa

November 18, 2021

GenSight Biologics reported a second case of a patient with late-stage retinitis pigmentosa (RP) who partially recovered her visual function after treatment with GS030 optogenetic therapy.

“We are delighted by the highly encouraging signs emerging from PIONEER, which are demonstrating the promise of optogenetics to treat one of the most common blinding genetic disorders,” Bernard Gilly, Co-Founder and Chief Executive Officer of GenSight, said in a company news release. “We will eagerly push forward towards the realization of a treatment for retinitis pigmentosa patients.”

One year after receiving the GS030 gene therapy component, the patient was able to recognize and count objects thanks to the optogenetic treatment, which combines gene therapy with the use of light-stimulating goggles.

The patient, like another patient whose partial recovery was published as a case study in Nature Medicine in May 2021, is a participant in the ongoing PIONEER phase 1/2 clinical trial of GS030.

The patient, whose progress is documented on camera, had been diagnosed with retinitis pigmentosa 20 years prior to enrolment and could barely see light at the time of injection.

She had a single intravitreal (IVT) injection of GS030 gene therapy in her worse-seeing eye with the medium dose (1.5E11 vector genomes) and began training on how to use the device after 4 months.

Twelve months after injection, the patient could detect and properly locate items of various sizes and contrasts placed on a white table in front of her, with a 57% success rate when wearing the GenSight light-stimulating goggles, compared to only 24% when not wearing the device.

A video of the patient performing the tests can be viewed at

The patient was featured in an update on PIONEER that was presented by Dr. José-Alain Sahel, MD at the Retina Sub-Specialty Day of the American Academy of Ophthalmology (AAO) annual meeting (November 12-15, 2021).

Dr. Sahel also gave an update on the GS030 safety. The optogenetic therapy has been well-tolerated in the 9 participants treated to date for up to 3 years following a single intravitreal injection. There have been no systemic concerns with gene therapy, no adverse events leading to the study's termination, and no participant withdrawal.

In September 2021, after reviewing the safety data for the first three cohorts of the PIONEER trial, the independent Data Safety Monitoring Board recommended the use of the highest dose of the gene therapy (5E11 vector genomes) in the extension cohort.

The topline results of the trial are expected to be released in the second half of 2022.