Safety of Autologous Human Schwann Cells (ahSC) in Subjects With Subacute SCI

Schwann cells are excellent candidates for transplantation into humans with SCI. Large numbers of ahSC can be derived for autologous implantation after a minor surgery for peripheral nerve harvesting, and purification and expansion of the cells in culture. Autologous cells offer important safety advantages that include no need for immune suppression, minimal risk of disease transfer, and a low risk of tumorigenicity. Since 1990, scientists at the Miami Project to Cure Paralysis have generated extensive preclinical data suggesting Schwann cell transplantations are successful in rodents with SCI. The most recent work has focused on contusive injury models that are relevant to human injury. They have also been largely responsible for developing an efficient method for procuring large, essentially pure populations of human Schwann cells from adult peripheral nerve. The rationale for implantation of ahSC in people with acute SCI is based on the evidence that Schwann cells are neuroprotective and are capable of myelinating axons. Using mitogen expanded human Schwann cells in SCID mice and athymic female nude rats demonstrated that human Schwann cells can survive and are capable of enhancing axonal regeneration and forming myelin after transplantation in animals with sciatic nerve transection or thoracic spinal cord transection. The proposed clinical trial will advance knowledge about the safety and feasibility of a cell-based treatment strategy for human SCI. This Phase 1 clinical trial will employ an open label, unblinded, nonrandomized and non-placebo controlled dose-escalation design to evaluate the safety of transplantation of ahSC transplantation in subjects with subacute SCI. A sural nerve harvest will occur within 30 days post-injury. Standard-of-care medical treatment and rehabilitation will proceed while the cells are being processed in a cGMP facility. No later than 72 days post-injury, the ahSC product will be administered via a single injection into the cavity of the spinal cord lesion. Safety and efficacy assessments will be performed at week 1 and 2 post-transplantation and 2, 6, and 12 months post-transplantation.