In 2010, Paul Bresge sat in a doctor’s office in Toronto with his fifteen year old daughter Tamar.

She had been experiencing vision problems. The diagnosis came quickly. Retinitis pigmentosa. A degenerative disease that slowly destroys the retina, often causing complete blindness by middle age. The doctor delivered the news in two or three minutes. There was nothing that could be done. Here is a handbook to the Canadian National Institute for the Blind.

The appointment was over.

Paul made Tamar a promise that day.

Her responsibility was to go on with her life. To do everything she had ever wanted to do. His responsibility was to figure out the rest.

He had no background in biotech. He had spent his career in pharmaceutical and cosmetic manufacturing. But he went home and started reading. Every paper he could find on retinal disease. Every clinical trial. Every research team working on something that might one day help.

He found a husband and wife research duo at UC Irvine doing early cell therapy work in mice. The data was preliminary but the concept was compelling. Paul tracked them down, got involved, and helped found his first biotech company around their science. That company became jCyte. It got into clinical trials. It gave Paul a real education in what it takes to move a therapy from a lab into a human being.

And then he read about optogenetics.

The idea stopped him. Most approaches to retinal disease were trying to slow the damage down or repair the cells that were lost. Optogenetics was doing something entirely different. It was reprogramming the cells that remained. By delivering a bioengineered light sensitive protein directly into the eye, you could teach surviving neurons to do what the destroyed photoreceptors could no longer do. Sense light. Send signals to the brain. Restore vision.

Not slow the decline. Restore vision.

A month after leaving jCyte, Paul co-founded Ray Therapeutics.

What makes Ray’s approach different from most gene therapies in this space is worth understanding. Most retinal gene therapies work by correcting a specific genetic mutation, which means they only help patients with that exact mutation and typically only in earlier stages of disease. Ray’s optogenetic approach is mutation agnostic. It does not matter what caused the blindness. If there are surviving neurons in the retina, Ray’s therapy is designed to reach them. That opens the door to a much broader population of patients, including people in more advanced stages of disease who have been told, as Tamar was, that there is nothing left to try.

The lead program RTx-015 is now in clinical trials for retinitis pigmentosa. It is delivered as a single injection. Patients begin showing results within months. The FDA recently granted it Regenerative Medicine Advanced Therapy designation, one of the most significant signals the agency can send to a clinical stage company.

In April 2026 Ray Therapeutics closed a $125 million Series B. Oversubscribed. Led by Janus Henderson Investors with participation from Franklin Templeton, Merck and some of the most respected names in biotech investing.

Paul Bresge started this because a doctor told him there was nothing that could be done for his daughter. He had no science background. No biotech network. No obvious reason to believe he could change that outcome.

He just could not accept the alternative.

Sixteen years later his company is in clinical trials, backed by $125 million, and working toward the moment when someone like Tamar sits in a doctor’s office and hears something different.

That is what Ray Therapeutics is.