Patients with very low vision who received implants of human embryonic stem cell-derived (hESC) RPE cells have reported subjective improvements in visual acuity, colour and contrast.
This is the first clinical trial to transplant hESC-derived RPE cells into human patients who showed no untoward pathologic reactions, according to Ninel Z. Gregori, Assistant Professor of Ophthalmology at University of Miami Health.
Professor Gregori’s study aims to evaluate the safety and tolerability of subretinal transplantation of hESC cells in patients with dry age-related macular degeneration.
“Human embryonic stem cells are a robust renewable source of terminally differentiated, young, healthy [retinal pigment epithelium] cells,” she said.
When explaining the study to an audience at the Angiogenesis, Exudation and Degeneration Meeting 2014 in Miami, Professor Gregori said the RPE is a good choice for transplantation because RPE loss is a common feature of many retinal degenerations causing blindness; RPE loss leads to photoreceptor loss, and the RPE is non-synaptic and surgically accessible.
She said in the phase 1/2 study to date, subretinal transplantation of hESC-derived RPE cell suspension in patients with advanced dry age-related macular degeneration and Stargardt’s disease had led to no abnormal proliferation, teratoma formation, retinal detachment or graft rejection.
Twelve patients with advanced dry age-related macular degeneration demonstrated by greater than 250 µm of center-involving geographic atrophy and best corrected visual acuity of 20/400 or worse in the transplant eye were separated in groups of three to receive 50,000, 100,000, 150,000 or 200,000 human embryonic stem cell-derived RPE cells. Patients will be followed for one year and beyond.
“Subjective improvements in visual acuity, colour and contrast have been reported by patients,” said Professor Gregori. “But the caveat is that it is complicated to reliably measure visual outcomes in very low
vision patients.”
