First patient treated with potential retinitis pigmentosa treatment from Sumitomo Pharma America Cell therapy DSP-3077 is in Phase 1/2a clinical trials

Sumitomo Pharma America treated its first patient in a Phase 1/2a clinical trial for an emerging retinitis pigmentosa (RP) treatment called DSP-3077. The clinical trial plans to treat 12 adults with one of two different doses to evaluate safety and effectiveness of the treatment among patients who have RP.

About retinitis pigmentosa

Retinitis pigmentosa is a group of inherited retinal diseases that cause progressive loss of night and peripheral vision. The condition often leads to legal and sometimes complete blindness and affects about 100,000 people in the U.S. Mutations in more than 80 genes are linked to RP. In other cases, individuals may also have symptoms in other organs, which is called syndromic RP, and includes Usher syndrome and Bardet-Biedl syndrome.

How the treatment works

DSP-3077 is a regenerative cell therapy that uses stem cells – master cells that can specialize into any cell in the body – to create sheets of retinal cells. During the trial, retinal sheets are injected below the retina in one eye of patients with RP. Patients will be followed for five years.

The path towards approval

In March 2026, Sumitomo Pharma received an FDA Orphan Drug Designation for DSP-3077, providing benefits and incentives like tax credits and temporary market exclusivity to encourage pharmaceutical companies to develop treatments for rare conditions. The Phase 1/2 study currently underway began in April 2026.

How the Foundation is moving RP research forward

The Foundation has provided funding for many early-stage research projects on retinitis pigmentosa that have since progressed and are making their way through clinical trials and approvals as potential treatments for use in patients.  SeeResearch Advances on RP and our Clinical Trial Pipelinefor more information.