ASRS 2025: David Liao, MD, PhD, shares the 126-week results from the REMAIN study

David Liao, MD, PhD, from Retina Vitreous Associates Medical Group in Los Angeles presented long-term follow-up data for MCO-010, a treatment candidate for patients with retinitis pigmentosa (RP). This talk was given at the annual scientific meeting of the American Society of Retina Specialists (ASRS), which was held in Long Beach, California from July 30 through August 2, 2025.

The study enrolled patients with severe vision loss (no greater than 20/1600) and divided them into 3 groups: low-dose, high-dose, and sham treatment groups. Participants received a single intravitreal injection and were monitored for up to 100 days in the original study, with follow-up extending to 2.5 years in the subsequent study. The results demonstrated meaningful and durable vision improvements with a favorable safety profile.

Liao emphasized the unique nature of optogenetics compared to emerging gene therapies for inherited retinal diseases. Unlike gene therapies that target specific mutations, MCO-010 worked by making non-photoreceptor cells sensitive to light, allowing it to benefit patients regardless of their underlying genetic mutation. MCO-010's mechanism was particularly elegant, as it targeted bipolar cells and remained sensitive across the visible light spectrum while utilizing ambient light. This approach made it suitable for patients with advanced disease who had exhausted other treatment options.

Based on the promising long-term follow-up data, the developers submitted a rolling FDA biological licensing application (BLA), with potential approval information expected by 2026. Additional studies were planned to gather more comprehensive data on the treatment's performance.

Liao reflected on the historical challenge retina specialists faced when counseling patients with inherited retinal diseases, often having to promise treatments "in another five or ten years." MCO-010 represented a significant breakthrough, with patients gaining approximately 3 lines of Snellen equivalent vision despite their advanced vision loss. While acknowledging that MCO-010 wouldn't be a universal cure, Liao expressed optimism about this new treatment option. The therapy's ability to work across different genetic mutations meant it could potentially help a large population of patients with inherited retinal diseases, offering genuine hope after years of limited treatment options.