A first-in-human trial has shown that a photoswitch drug can revive damaged retinal cells, offering a potential new treatment for retinitis pigmentosa without the need for gene therapy.
Adelaide, Australia – Researchers from Adelaide University, in collaboration with the University of Washington, have completed a first-in-human pilot trial of a novel photoswitch drug for retinitis pigmentosa, a genetic condition that leads to progressive blindness.
The Study
The small pilot trial was designed to test the safety and tolerability of a small molecule injected directly into the eye. The results, published in Nature Medicine, indicate that the treatment revived some damaged retinal cells, making them sensitive to light even after normal light-sensing cells had been lost.
Key Findings
- No serious adverse events were reported, according to the principal investigator, Professor Robert Casson.
- Brain imaging showed activity in visual areas following treatment, confirming that the restored light sensitivity was being processed by the brain.
- Some participants reported short-term improvements in visual tests, including walking tasks.
- One participant with severely damaged retinal cells reported greater light perception within two days of the injection.
"The findings are preliminary and require confirmation in larger studies," Professor Casson stated.
A Broader Impact
Unlike many emerging treatments for retinal degeneration, this drug avoids genetic modification, meaning it could potentially apply to multiple forms of retinal degeneration beyond retinitis pigmentosa.
Next Steps
A larger Phase 2 trial is already underway. Industry support for the research was provided by Kiora Pharmaceuticals.