Aug 12, 2026 —
Sumitomo Pharma America announced that the first patient has undergone subretinal implantation in a Phase 1/2a clinical study evaluating DSP-3077, its investigational allogeneic iPS cell-derived retinal sheet therapy for non-syndromic retinitis pigmentosa, or RP.
DSP-3077 is an investigational regenerative cell therapy composed of allogeneic induced pluripotent stem cell-derived retinal sheets. The product is based on a three-dimensional retinal organoid generated using a self-organizing cell culture technique and processed into multilayered retinal sheets containing retinal tissue structure and abundant photoreceptor precursors.
The Phase 1/2a study is an open-label, single-arm, uncontrolled, dose-escalation trial evaluating two dose levels of DSP-3077 administered through a single subretinal, uniocular injection in adults with RP.
The primary objective is to assess safety and tolerability. Additional objectives include evaluating engraftment, potential therapeutic response, and delivery device performance. The study will enroll three cohorts defined by visual acuity criteria and dose level, with four participants per cohort for a total of 12 participants.
Retinitis pigmentosa is a rare progressive hereditary retinal disorder affecting approximately 1 in 4,000 individuals. The disease is characterized by degeneration of rod and cone photoreceptor cells, leading first to loss of night and peripheral vision and, in many cases, eventual central vision loss. Current curative treatment options are limited.
The technology underlying DSP-3077 is based on the SFEBq method, a self-organizing cell culture technique used to generate three-dimensional neural tissues and organoids from pluripotent stem cells. The method was originally developed by Yoshiki Sasai’s research group at RIKEN in Japan.
Sumitomo Chemical previously conducted joint research with RIKEN to improve the technology, and Sumitomo Pharma later continued joint research to develop a manufacturing process for iPS cell-derived retinal sheets. Sumitomo Pharma America, Sumitomo Pharma, RACTHERA, and S-RACMO are continuing research to further improve the platform and expand its applications in retinal regenerative therapy.
The FDA granted Orphan Drug Designation to DSP-3077 for the treatment of retinitis pigmentosa in March 2026.
The first patient implantation marks an early clinical milestone for iPSC-derived retinal regenerative medicine and supports continued evaluation of retinal sheet transplantation as a potential approach to replacing or supporting degenerating photoreceptor cells in RP.
