Therapeutic Hypothermia for Acute Spinal Cord Injury
ARCTIC is the acronym for our next clinical trial testing the safety and efficacy of therapeutic hypothermia (cooling) in SCI, Acute Rapid Cooling Therapy for Injuries of the Spinal Cord. We have already completed a Phase I clinical trial to start learning whether inducing hypothermia within the first few hours of traumatic SCI is safe and makes a difference in the severity of injury. When people with new cervical SCI were brought to the trauma center, doctors placed a cooling catheter in a large blood vessel (vena cava) that allows them to cool the body a few degrees to 33 degrees Celsius (or 92 degrees Fahrenheit). In that trial the cooling was started within 9 hours post-injury, on average, and was maintained for 48 hours. After which, participants were slowly re-warmed at one degree every eight hours and then proceeded with standard medical care. In that initial trial there were no serious safety concerns and there was a trend for more people to recovery more function after 1 year post-injury than would normally occur spontaneously.
ARCTIC will be a Phase II/III clinical trial where we will evaluate the safety of different durations of hypothermia, initiated within 6 hours post-injury, and then confirm the efficacy of the best duration. We have taken what may seem like a long time to plan this clinical trial, but for many good reasons. One, predicting whether someone has a “complete” or “incomplete” SCI within the first 6 hours is VERY difficult and unreliable. In fact, it is not reliable until after 72 hours post-injury. However, because we have such a short time window in which to intervene with hypothermia, it is a complication we must deal with. Two, this trial will involve more than 200 people with acute SCI and cost several million dollars. We have been working with the National Institutes of Health sponsored Neurologic Emergencies Treatment Trials (NETT) network for review and, hopefully, funding. Three, we have to get this right, the SCI field needs it! There have been too many “failed” Phase III clinical trials because of design issues. Drs. Michael Wang and Dalton Dietrich have been working with several experts in clinical trial design and statistics to develop the most appropriate design to capture clinically meaningful improvements yet still be responsive to unknown safety issues. If this pivotal trial gets funded and the data positively demonstrate that the benefits significantly outweigh the risks, we could change the standard of care for SCI medicine worldwide.