Asian Promise For Ocata’s Macular Degeneration Cell Therapy
This article was originally published in PharmAsia News
Executive Summary
U.S. regenerative ophthalmology venture Ocata Therapeutics has disclosed new positive top-line results from the first ever clinical trial in Asian patients with a stem cell-derived cell therapy.
The newly published findings for Ocata Therapeutics Inc.'s retinal pigment epithelium (RPE) cells, derived from human embryonic stem cells (hESCs) using Ocata's proprietary DeltaCell platform technology, showed clear signs of visual improvement and have validated the potential utility of the therapeutic approach.
Based on the results, the Massachusetts-based firm is now planning to initiate a full Phase II study in dry age-related macular degeneration (AMD) and a pivotal trial in Stargardt's macular degeneration (SMD), the two targeted indications.
There is currently no effective treatment for either condition, both of which are characterized by the loss or damage of the RPE layer and the breakdown of photoreceptor cells in the center of the retina. Animal studies had suggested that sub-retinal transplantation of RPE cells derived from stem cells can help rescue photoreceptor function.
Dry (non-exudative) AMD accounts for around 90% of AMD cases globally, which are projected to reach 196 million in 2020, with 1.8 million new diagnoses annually in the U.S. alone at present.
SMD, the most common form of juvenile macular degeneration, is caused by the production of defective rim proteins encoded by the ABCA4 gene, which eventually cause photoreceptor death. The orphan disease has a prevalence of around one in 10,000 in the U.S.
While other regenerative therapy trials in the field are underway, the small Ocata trial is the first to confirm the potential safety and efficacy of a pluripotent stem cell therapy in Asian patients, who may carry different gene variants and risk alleles linked to AMD, the venture noted.
In the results published online in Stem Cell Reports, the safety-focused study found no adverse proliferation, ectopic tissue formation or teratoma formation (tumorigenicity), one of the main concerns of stem cell therapies.
The trial, conducted in two dry AMD and two SMD patients in South Korea by the local stem cell technology firm CHA Biotech, involved 12 months of follow-up, and found a 9-19 letter improvement in visual acuity in three patients and stable visual function in the other. Patches of increasing pigmentation were also observed.
The findings followed similar positive results published in The Lancet last October and provide "further evidence that hESC-derived cells could serve as a potentially safe new source for regenerative medicine," said Dr. Robert Lanza, Ocata's chief scientific officer.
A total of 42 patients have now been treated in several studies using Ocata's technology, and the feasibility and preliminary safety are now seen as confirmed by the trial.
Elsewhere in Asia, a five-patient Japanese trial in wet (rather than dry) AMD patients is underway, using transplanted RPE cells derived from induced pluripotent stem cells. This only started last year however, and so far one subject has reported subjective improvements in vision (Also see "First iPS Cell Trial Underway But A Long Way To Go" - Scrip, 17 Sep, 2014.).
Nasdaq-listed Ocata is also investigating photoreceptor progenitor cell therapy in dry AMD and SMD, RPE therapy in myopic macular degeneration, and other cell therapies for retinitis pigmentosa, glaucoma, corneal blindness and allogeneic therapies for other disorders.