Human embryonic stem cell-derived RPE cell transplantation yields no ‘untoward pathologic reactions’
MIAMI — A study under way to evaluate safety and tolerability of subretinal transplantation of human embryonic stem cells in patients with dry age-related macular degeneration so far has yielded no “untoward pathologic reactions,” a speaker said here.
“Human embryonic stem cells are a robust renewable source of terminally differentiated, young, healthy [retinal pigment epithelium] cells,” Ninel Z. Gregori, MD, told colleagues at the Angiogenesis, Exudation, and Degeneration 2014 meeting. “This is the first clinical trial transplanting hESC-derived RPE cells into human patients.”
Ninel Z. Gregori
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, Gregori said.
In the phase 1/2 study to date, subretinal transplantation of hESC-derived RPE cell suspension in patients with advanced dry AMD and Stargardt’s disease has led to no abnormal proliferation, teratoma formation, retinal detachment or graft rejection, she said.
Twelve patients with advanced dry AMD 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 1 year and beyond.
“Subjective improvements in visual acuity, color and contrast have been reported by patients,” Gregori said. “But the caveat is that it is complicated to reliably measure visual outcomes in very low vision patients.”
Disclosure: Gregori has no relevant financial disclosures.