PRIME Designation Follows Recent FDA Regenerative Medicine Advanced Therapy Designation, Continues Regulatory Momentum for RTx-015

Ray Therapeutics (RayTx), an industry-leading clinical-stage biopharmaceutical company pioneering differentiated vision restoration therapies for those living with severe retinal degenerations, today announced that the European Medicines Agency (EMA) has granted Priority Medicines (PRIME) designation to its lead program, RTx-015, for the treatment of retinitis pigmentosa (RP).

PRIME (PRIority MEdicines) is awarded to therapies that have the potential to address significant unmet medical need and provide meaningful therapeutic advantage based on early clinical or compelling nonclinical evidence. This designation emphasizes the global regulatory support for RTx-015 following the April 2026 announcement of the U.S. Food and Drug Administration (FDA) Regenerative Medicine Advanced Therapy (RMAT) designation.

“Receiving PRIME designation for RTx-015 in RP from the EMA, alongside our recent RMAT designation from the FDA, is a powerful validation of our science and clinical outcomes, and the urgent need we are addressing,” said Paul Bresge, CEO and Co-Founder of Ray Tx. “There are more than a million people living with retinitis pigmentosa who have no treatment options to augment their vision and improve their quality of life. These designations accelerate our ability to advance RTx-015 globally and deliver on our mission to restore vision for patients living with blinding diseases.”

RTx-015, a first-in-class, genotype-independent optogenetic gene therapy administered via a single intravitreal injection, is being developed for the treatment of retinitis pigmentosa (RP), a progressive inherited retinal disease, and one of the leading causes of blindness. RP causes the irreversible degeneration of rod and cone photoreceptors, resulting in tunnel vision and eventual complete or near-complete vision loss. Despite the profound impact of the disease on patients' independence, mobility, and quality of life, no effective treatment is currently available for patients with advanced RP.

The EMA's PRIME designation was granted as a result of compelling preliminary safety and efficacy results from the ongoing Phase 1/2 study of patients with advanced disease. Improvements in vision in the treated eye were observed across all dose levels. These results support RTx-015's potential to meaningfully restore visual function to patients with retinitis pigmentosa.

About Ray Therapeutics

Ray Tx is a clinical-stage biopharmaceutical company advancing optogenetic therapies to restore vision in patients with retinal degenerative diseases. By delivering a bioengineered, highly light-sensitive protein to targeted retinal cells, the approach is designed to improve visual function regardless of the underlying genetic mutation.

RTx-015 is Ray Therapeutics’ lead optogenetic gene therapy currently being evaluated in patients with retinitis pigmentosa. Delivered as a single intravitreal injection, the treatment aims to restore functional vision to those with advanced visual impairment.

This research was additionally made possible by funding from the California Institute for Regenerative Medicine (CIRM), a state agency in California that supports research in regenerative medicine, stem cell therapy, gene therapy, and clinical trials (Grant number: CLIN2-17086).

Ray Therapeutics has a second clinical-stage program, RTx-021, which has been designed to restore vision to those with macula diseases, such as Stargardt disease and geographic atrophy age-related macular degeneration (GA AMD) by targeting retinal bipolar cells. Several of these programs are supported by grants from the California Institute for Regenerative Medicine (CIRM).

For more information, visit www.raytherapeutics.com.

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