May 31, 2019 Conference
Clinical trials are in progress for atrophic age related macular degeneration and there are a spectrum of therapeutic strategies. Immune modulation therapies (complement pathway) have demonstrated mixed results - although some continue into phase 3 clinical trials and new phase 1 trials are starting. Most cell based therapies currently utilize hESC derived human RPE cells delivered to the subretinal space in subjects with atrophic AMD; one clinical trial utilizing umbilical cord derived cells delivered to the subretinal space did not demonstrate a reduction in progression of geographic atrophy. Safety issues have been generated from "stem cell clinics" injecting lipid derived autologous cells into the vitreous cavity. Independent data monitoring is important for patient safety.
Surgical delivery of hESC derived human RPE cell suspensions have shown early promise in independent trials with potential engraftment of RPE cells noted at the border of geographic atrophy. More data and further refinement of surgical delivery of cell suspensions are required since epiretinal membrane formation has been observed and may be related to cell egress through a retinotomy. An ab externo surgical approach to the subretinal space via a suprachoroidal microcatheter obviates the need for a vitrectomy or retinotomy and may improve dosing precision and reduce epiretinal membrane formation.
A composite sheet of hESC derived human RPE cells on an ultrathin polymer has been surgically implanted into the subretinal space in areas of atrophy and has been well tolerated in an early phase clinical trial. There may be potential for improved visual function over this RPE transplant.