A drug for treating multiple sclerosis was discovered at
Rush University Medical Center, was approved by the Food and Drug
Administration (FDA) in January and is now available in the United States.
The drug, called dalfampridine, is the first therapy for
multiple sclerosis that can be taken orally. It is also the first FDA-approved
therapy to treat impaired walking, a debilitating symptom of the disease
limiting patients’ independence and ability to accomplish the most basic tasks
of daily living. While other multiple sclerosis drugs work by decreasing the
inflammation that causes damage to the central nervous system, dalfampridine is
designed to allow conduction of nerve impulses despite the damage.
Research that led to the discovery of
dalfampridine’s therapeutic value dates back to the 1960s, when Floyd
Davis MD, then a neurologist in training and later a physician at Rush, became
intrigued by an unusual clinical observation: many multiple sclerosis patients
fare better when their body temperature is slightly lowered, even by just two-
or three-tenths of a degree.
“In multiple sclerosis, the protective myelin
sheath that wraps around nerve fibers in the brain and spinal cord is damaged,
essentially causing a short circuit,” Davis, who is now retired, said in a
news release. “Somehow, lower body temperature enabled the electrical
pulse to continue its travel along the nerve fibers. I was completely
transfixed by the significance of that fact.”
It was important because it showed “that the
damaged nerve fibers were not doomed, as previously believed,” Dusan
Stefoski, MD, director of the Rush Multiple Sclerosis Center, who teamed up
with Davis in 1978, shortly after completing neurology training at Rush, said.
Stefoski said that although the drug has been approved
specifically for the treatment of impaired walking, it also relieves other
symptoms of multiple sclerosis, since it restores signal conduction in all the
affected nerve fibers.