A therapy derived from human embryonic stem cells that was used to treat two visually devastating retinal conditions appears to be both safe and effective, according to a novel study in the January 23 online version of Lancet.
Principal investigator Steven Schwartz, M.D., performs the stem cell transplantation procedure. Photo: UCLA Newsroom
In this study, researchers at UCLA’s Jules Stein Eye Institute conducted two prospective, open-label clinical trials to assess the safety and tolerability of retinal pigment epithelium (RPE) cells that were derived from human embryonic stem cells. The researchers injected the RPE cells into two subjects—one with Stargardt’s macular dystrophy and the other with dry age-related macular degeneration—and followed their progression for four months.
At four-month follow-up, the researchers noted that the injected cells had properly integrated into the respective hosts’ RPE layers and continued to persist throughout the study period. More importantly, both patients experienced an overall improvement in visual quality following cell transplantation.
“Best-corrected visual acuity improved from hand motions to 20/800 (and improved from zero to five letters on the Early Treatment Diabetic Retinopathy Study [ETDRS] visual acuity chart) in the study eye of the patient with Stargardt’s macular dystrophy, and vision also seemed to improve in the patient with dry age-related macular degeneration (from 21 ETDRS letters to 28),” the researchers wrote.
Additionally, the researchers experienced no safety complications associated with the procedure. “We did not identify signs of hyperproliferation, abnormal growth or immune-mediated transplant rejection in either patient during the first four months,” they wrote.
In the next several months, the researchers aim to increase the populations of both clinical trials to a total of 24 subjects (12 with Stargardt’s and 12 with dry AMD) to further evaluate the procedure’s safety and tolerability.
Building upon this early success, the authors ultimately hope to treat patients with such degenerative retinal conditions earlier in the disease process to increase the likelihood of photoreceptor and central visual field rescue.
Schwartz SD, Hubschman JP, Heilwell G, et al. Embryonic stem cell trials for macular degeneration: a preliminary report. Lancet. 2012 Jan 24. [Epub ahead of print]
