Neuralstem has announced that it has filed an Investigational New Drug (IND) application with the US FDA to begin a phase I safety clinical trial for chronic spinal cord injury (SCI) with its spinal cord stem cells.
This multicentre phase I safety trial will enrol a total of 16 long-term, or chronic, spinal cord injury patients, with an American Spinal Injury Association (ASIA) Grade A level of impairment, one-to-two years post-injury. ASIA A refers to a patient termed to be in “complete paralysis”, with no motor or sensory function in the relevant segments.
“We are filing an application with the FDA to test our spinal cord stem cells in a second medical condition with substantial unmet needs,” said Neuralstem CEO and president, Richard Garr. “The proposed trial is primarily designed to test the safety of both our cells and delivery method in chronic spinal cord injury patients.”
Clinical studies with chronic SCI patients have demonstrated that, even several years after motor- and sensory-complete SCI, intensive and task-specific rehabilitation can improve motor function as measured by the ASIA Impairment Scale (AIS). These clinical experiences, together with results from numerous animal studies of SCI, illustrate that even the complete, chronically-injured cord can undergo some degree of recovery and reorganisation.
Transplantation of Neuralstem’s human spinal stem cells (HSSC) is meant to provide a neuron-rich substrate to the injured segments of a patient’s spinal cord to promote further repair, regeneration, and reorganisation, the goal being to harness and promote reorganisation by combining stem cell transplantation with the modern concept of activity-guided rehabilitation.
Currently, no predictive animal model of chronic human SCI exists. However – as a 2007 Neuroscience report in conjunction with the University of California once stated – in a rat model of ischaemia-induced spinal cord injury that generates the condition of permanent paraplegia, transplantation of Neuralstem’s HSSC into the injury site leads to significant motor recovery. Detailed analysis revealed robust graft survival, extensive neuronal differentiation, and integration of grafted cells into the host circuitry, all outcomes believed to be essential for recovery of function in human patients.
Chief scientific officer and founder Karl Johe has stated, “We believe that it is the right time to leverage what we have learned with ALS in spinal cord injury. We are proposing to transplant patients with injuries in the thoracic (mid-back) regions first. Once the safety of the surgeries has been established, we plan to transplant patients whose injuries are in the cervical (upper spinal cord) region.”