|Human induced pluripotent stem cells (iPS cells)|
The study will be led by Masayo Takahashi M.D., Ph. D. and will be conducted in collaboration with the Institute for Biomedical Research and Innovation with support from the Kobe City Medical Center General Hospital. Patient recruitment has opened since August 1, 2013.
The protocol for the new pilot study involves the establishment of autologous iPSCs from each of the research participants, which will then be differentiated into RPE using a novel technology that allows these epithelial cells to be transplanted in monolayer cell sheets without the use of synthetic scaffolds or matrices. The cell sheets will be shaped into 1.3 × 3 mm grafts and transplanted into the affected site of a single eye, following excision of the damaged RPE and neovascular tissues.
Transplant sites will be monitored closely for functional integration and potential adverse reactions for an initial intensive observation period of one year, and subsequent follow-up observation for three years. Production and validation of the autologous iPSCs and subsequent RPE cell sheets will take approximately 10 months, and will be conducted at a certified clinical-grade cell processing center. The initial three transplants will be conducted at intervals of at least eight weeks; the following three will be performed after a preliminary safety evaluation period.
This pilot study follows on extensive preclinical safety and feasibility testing, including evaluations of cell morphology, physiologic activity, gene expression, immunogenicity, and tumorigenesis in rodent and non-human primate models. The results of these preclinical studies have been submitted for publication in a peer-reviewed journal.
Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in "dry" and "wet" forms. Wet-type AMD ( officially called Neovascular or exudative AMD ) the "wet" form of advanced AMD causes vision loss due to abnormal blood vessel growth (choroidal neovascularization) in the choriocapillaris, through Bruch's membrane, ultimately leading to blood and protein leakage below the macula. Bleeding, leaking, and scarring from these blood vessels eventually cause irreversible damage to the photoreceptors and rapid vision loss if left untreated. Only about 10% of patients suffering from macular degeneration have the wet type.
Currently available drug treatments for this disease focus on inhibiting neovascularization, but do not repair damage that may have already occurred prior to administration. A number of previous studies have tested the use of RPE cells from various sources, such as fetal tissue or unaffected parts of the RPE, for transplantation but have been complicated by problems of immune rejection or the need for invasive harvesting procedures.
For more information please visit http://www.riken.jp/en/pr/press/2013/20130730_1/