Ray Therapeutics has announced new funding from the California Institute for Regenerative Medicine (CIRM) to advance RTx-021, its optogenetic gene therapy being developed for Stargardt disease. Ray described the award as an $8 million grant in its September 30 announcement. CIRM’s governing board had approved $7,935,162 for the project on September 25.
The funding will support the ongoing Phase 1/2 clinical study of RTx-021 and manufacturing activities intended to prepare the program for later-stage development. RTx-021 is being evaluated in an open-label, dose-escalation study in patients with Stargardt disease and is designed to target retinal bipolar cells through a single intravitreal injection.
Founded in 2021 and based in Berkeley, California, Ray Therapeutics is a clinical-stage biotechnology company developing optogenetic therapies for degenerative retinal diseases. Its approach uses bioengineered light-sensitive proteins delivered to surviving retinal cells with the aim of improving visual function independently of the underlying genetic mutation. Paul Bresge is the company’s CEO and co-founder.
Ray’s pipeline also includes RTx-015, an optogenetic gene therapy being developed for retinitis pigmentosa and other inherited retinal diseases. In April 2026, the company closed a $125 million Series B financing led by Janus Henderson Investors to support development of RTx-015 and RTx-021.
