Subretinal delivery of cells via the suprachoroidal space: Janssen trial

Cell therapies are currently in clinical development for the treatment of a number of retinal disorders. Such therapies must be delivered to the subretinal space, which has traditionally been accomplished through conventional pars plana vitrectomy with the creation of a retinotomy and subsequent transfer of cells. Delivering cells in this fashion is thought to incur a risk of retinal detachment and the development of proliferative vitreoretinopathy. Indeed, preclinical studies of palucorcel (human umbilical tissue derived cells developed by Janssen Research & Development for the treatment of geographic atrophy secondary to age related macular degeneration) delivered using this tranvitreal approach suggested that the presence of these cells in the vitreous had the potential to stimulate ERM formation and retinal detachments due to PVR. Accordingly, Janssen began to explore alternative routes to the subretinal space. After considering a number of potential techniques, they developed a novel approach using the suprachoroidal space as a conduit to the posterior pole. This approach involves the creation of a sclerotomy, introduction of a specialized cannula into the suprachoroidal space, advancement of the cannula under direct visualization to the desired delivery site, advancement of an internal needle through the choroid into the subretinal space, and delivery of cells. The system has completed small-scale preclinical validation studies and is now being tested in conjunction with clinical trials of palucorcel for the treatment of geographic atrophy secondary to ARMD. There is optimism surrounding these trials as well as the device's specific design to access the subretinal space.