4BIO Capital portfolio company Ray Therapeutics announces upsized and oversubscribed $125 Million Series B financing for vision restoration treatments

·         4BIO Capital continues support as founding investor, having backed Ray Therapeutics since seed funding in 2021 through Series A (2023)

·         Proceeds to support two ongoing clinical-stage programs: RTx-015 for retinitis pigmentosa and RTx-021 for macular diseases including Stargardt disease and geographic atrophy AMD

London, United Kingdom, 21 April 2026 - 4BIO Capital, a specialist biotech venture firm transforming innovative technologies into breakthrough precision therapies, today announces that its portfolio company, Ray Therapeutics, an industry-leading clinical-stage biopharmaceutical company pioneering differentiated vision restoration therapies for those living with severe retinal degeneration, has closed an upsized and oversubscribed $125 million Series B financing. 

The announcement follows Ray Therapeutics' recent receipt of Regenerative Medicine Advanced Therapy (RMAT) Designation from the U.S. Food and Drug Administration for its lead clinical program, RTx-015, for the treatment of retinitis pigmentosa (RP).

4BIO Capital has continued its support as a founding investor in Ray Therapeutics, having led the seed funding in 2021, and participating in the Series A (2023) and now Series B rounds. The round was led by Janus Henderson Investors, with participation from additional new investors Invus, Franklin Templeton, Adage Capital Management, and Marshall Wace. The financing included strong follow-on support from other existing investors Novo Holdings, Deerfield Management Company, Norwest, Platanus and MRL Ventures Fund.

Ray Therapeutics is pioneering an innovative optogenetic approach to vision restoration that is designed to work regardless of the underlying cause of disease and can address rare inherited retinal disorders, such as retinitis RP, and larger indications, such as geographic atrophy. While other approaches typically focus on slowing disease progression, Ray Therapeutics’ differentiated technology is bioengineered to restore visual function by reprogramming targeted retinal cells.

“Ray Therapeutics has continued to make rapid progress since 4BIO Capital supported its seed and Series A fundraises in 2021 and 2023,” said Dima Kuzmin, Co-founder and Managing Partner at founding investor, 4BIO Capital, and member of the Ray Therapeutics’ Board. “The team has an outstanding track record in developing regenerative medicines for ophthalmology indications, and Ray's novel use of light-sensitive proteins to restore visual function in damaged retinal cells has enormous potential to help patients with inherited blinding disorders, who currently have very few treatment options. As a founding investor and strategic partner, we have worked closely with the Ray Therapeutics team to navigate the complex regulatory and clinical development pathway. We are excited to continue supporting the company and look forward to their continued success as they progress further through clinical development."

“This funding is a decisive endorsement of our vision restoration platform and underscores the value of our differentiated approach and the clinical and regulatory momentum we have achieved to date," said Paul Bresge, Chief Executive Officer and Co-Founder of Ray Therapeutics. “Following our recent receipt of the Regenerative Medicine Advanced Therapy (RMAT) Designation from the U.S. Food and Drug Administration for our lead clinical program, we are deeply appreciative of the tremendous enthusiasm for this financing among leading investors. I want to particularly acknowledge the 4BIO Capital team, who have been exceptional partners since our earliest days. Their deep scientific expertise, strategic guidance, and unwavering support have been instrumental in helping us navigate the complexities of clinical development and build Ray Therapeutics into the company it is today. Alongside 4BIO and our other existing investors, we're thrilled to welcome our new Series B investors, who bring exceptional track records in biopharmaceutical value creation. Together, we share an unwavering commitment to delivering life-changing treatments for patients living with blinding diseases."