• Stem Cell-Derived RPE Cell Transplants for Advanced Dry AMD

    During Sunday’s Retina, Vitreous original papers session, Eyal Banin, MD, PhD, shared phase 1 results from a multicenter study assessing the safety of subretinal transplantation of retinal pigment epithelium (RPE) cells derived from human embryonic stem cells (ESCs) as a treatment for advanced dry age-related macular degeneration (AMD).

    Study design. In this study, researchers subretinally injected a suspension of ESC-derived RPE cells (OpRegen; Cell Cure Neurosciences/BioTime) into 1 eye each of AMD patients in 4 cohorts. Recruitment for the first 3 cohorts, which include only legally blind patients, is complete (n = 12). Cohort 4 recruitment is currently ongoing. The main differences between the earlier and current cohorts are baseline visual acuity (23.7 vs. 55 letters) and geographic atrophy (GA) lesion area (12.7 vs. 7.1 mm2).

    Primary safety outcomes. Cohorts 1, 2, and 3 exhibit stable best-corrected visual acuity (BCVA) and GA over time in the treated eyes, with no intraocular pressure elevations. Dr. Banin noted that although all 12 patients reported at least 1 adverse event, nearly 80% of events were mild. Reported events included conjunctival hemorrhage (n = 7), new or worsening epiretinal membrane (n = 9), and lamellar hole (n = 2). There was 1 case of retinal detachment 2 weeks after surgery; however, Dr. Banin said, it is unclear if it was caused by the surgery or implanted cells.

    Anatomic and functional findings. Dr. Banin also provided details of secondary outcomes in the first 3 cohorts. Seven of the patients exhibited new subretinal hyperpigmentation after surgery. Five patients showed hyperreflectivity at the RPE level on OCT and 8 had hypo- and hyperfluorescent spots in the treated area. Earlier experiments in pigs suggest that irregular hyperreflectivity may be an indication of RPE engraftment.

    Cohort 4, currently in progress. Studies on cohort 4 are currently underway, and 3 patients have already received the cell transplant. Now that the investigators are treating patients earlier in the disease process, Dr. Banin hopes that the results will better clarify understanding of this therapeutic approach.

    Ultimately, he explained, if the treatment is safe and effective, the goal will be to treat patients earlier in AMD to prevent vision loss. — Kanaga Rajan

    Financial disclosure. Cell Cure Neurosciences: C. 

    Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.

    Next story from AAO 2018—Emerging Therapies for Dry Eye Target Underlying Causes: “Dry eye treatments have evolved significantly over the last decade or so as we’ve better understood the pathology and developed new options to diagnose and treat patients,” said Bennie H. Jeng, MD.