Key Takeaways
- • Ray Therapeutics closed an upsized and oversubscribed $125 million Series B funding round led by Janus Henderson Investors, bringing institutional capital into the optogenetic vision restoration space.
- • The round attracted five new institutional investors—Adage Capital Management, Franklin Templeton, Invus, and Marshall Wace—alongside continued support from seven existing backers including Merck's MRL Ventures Fund, Novo Holdings, and Deerfield Management.
- • Lead program RTx-015, a single intravitreal optogenetic gene therapy injection for retinitis pigmentosa, is in clinical-stage development and designed to restore functional vision regardless of underlying genetic mutation.
- • Secondary program RTx-021 targets retinal bipolar cells to address macular diseases including Stargardt disease and geographic atrophy age-related macular degeneration (GA AMD).
- • The financing reflects continued institutional investor appetite for next-generation ophthalmology platforms and gene therapy modalities in 2026 biotech venture markets.
Summary
Ray Therapeutics, a Berkeley-based clinical-stage biopharmaceutical company, has closed a $125 million Series B financing round, the company announced on April 22, 2026. The round was oversubscribed and upsized, indicating strong market demand for the company's optogenetic vision restoration platform. Janus Henderson Investors led the round, with participation from new institutional investors Adage Capital Management, Franklin Templeton, Invus, and Marshall Wace. Seven existing investors also participated, including 4BIO Capital, Deerfield Management, Merck's MRL Ventures Fund, Norwest, Novo Holdings A/S, and Platanus.
The company is advancing optogenetic therapies designed to restore vision in patients with severe retinal degenerative diseases. The approach delivers a bioengineered, highly light-sensitive protein to targeted retinal cells, with the stated goal of improving visual function independent of the underlying genetic mutation causing vision loss. This platform-agnostic mechanism represents a differentiated approach within the ophthalmology gene therapy sector.
Ray Therapeutics' lead program, RTx-015, is a clinical-stage optogenetic gene therapy for retinitis pigmentosa (RP), a progressive inherited retinal degeneration affecting approximately 1 in 4,000 individuals. The therapy is delivered as a single intravitreal injection and aims to restore functional vision in patients with advanced visual impairment. A second clinical-stage program, RTx-021, has been designed to address macular diseases including Stargardt disease and geographic atrophy age-related macular degeneration (GA AMD) by targeting retinal bipolar cells rather than photoreceptors.
The $125 million raise reflects institutional appetite for next-generation ophthalmology therapeutics and validates the optogenetic modality as a credible approach to vision restoration. The participation of Merck's corporate venture arm alongside established life sciences investors suggests confidence in the underlying science and commercial potential within the expanding rare ophthalmology market.
The company is advancing optogenetic therapies designed to restore vision in patients with severe retinal degenerative diseases. The approach delivers a bioengineered, highly light-sensitive protein to targeted retinal cells, with the stated goal of improving visual function independent of the underlying genetic mutation causing vision loss. This platform-agnostic mechanism represents a differentiated approach within the ophthalmology gene therapy sector.
Ray Therapeutics' lead program, RTx-015, is a clinical-stage optogenetic gene therapy for retinitis pigmentosa (RP), a progressive inherited retinal degeneration affecting approximately 1 in 4,000 individuals. The therapy is delivered as a single intravitreal injection and aims to restore functional vision in patients with advanced visual impairment. A second clinical-stage program, RTx-021, has been designed to address macular diseases including Stargardt disease and geographic atrophy age-related macular degeneration (GA AMD) by targeting retinal bipolar cells rather than photoreceptors.
The $125 million raise reflects institutional appetite for next-generation ophthalmology therapeutics and validates the optogenetic modality as a credible approach to vision restoration. The participation of Merck's corporate venture arm alongside established life sciences investors suggests confidence in the underlying science and commercial potential within the expanding rare ophthalmology market.
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