FDA says no to experimental treatment for multiple sclerosis
On May 10, the Food and Drug Administration (FDA) issued an alert advising against an experimental treatment procedure for multiple sclerosis (MS), which has been termed "liberation therapy" or the "liberation procedure."
The FDA notes that the procedure has been linked to serious complications, including stroke and death. The procedure is based on the premise of chronic cerebrospinal venous insufficiency (CCSVI), which is described by a stenosis (narrowing) of veins in the neck and chest. Some scientists contend that CCSVI may either cause multiple sclerosis or accelerate progression of the disease. The FDA contends that studies attempting to show a relationship between CCSVI and MS are inconclusive.
The procedure involves inserting a balloon or stent to dilate narrowed vessels in the chest and neck. Although, the procedure may increase blood flow to the brain, the FDA notes that the medical literature contains reports of cases of stroke, death, detachment and migration of the stents, damage to the treated vein, blood clots, cranial nerve damage, and abdominal bleeding associated with the procedure. The FDA notes that it has not approved either balloon angioplasty devices or stents for use in treating CCSVI. “Because there is no reliable evidence from controlled clinical trials that this procedure is effective in treating MS, FDA encourages rigorously-conducted, properly-targeted research to evaluate the relationship between CCSVI and MS,” noted William Maisel, MD, MPH., chief scientist and deputy director for science in the FDA’s Center for Devices and Radiological Health. “He added, “Patients are encouraged to discuss the potential risks and benefits of this procedure with a neurologist or other physician who is familiar with MS and CCSVI, including the CCSVI procedures and their outcomes.”
The FDA is notifying doctors and clinical investigators who are planning or conducting clinical trials using medical devices to treat CCSVI that they must comply with FDA regulations for investigational devices. The agency notes that any procedures conducted are considered significant risk clinical studies and require FDA approval; the approval is termed an investigational device exemption. In February 2012, the FDA sent a warning letter to a sponsor/investigator who was conducting a clinical study of CCSVI treatment without the necessary approval. In response to the request, the sponsor/investigator voluntarily terminated the study. The FDA notes that complications following CCSVI treatment can be reported through MedWatch, the FDA Safety Information and Adverse Event Reporting program.
MS is an autoimmune disease that affects the brain and spinal cord (central nervous system). The disease affects woman more than men; it most commonly begins between ages 20 and 40; however, it can occur at any age. MS is caused by damage to the myelin sheath, the protective covering that surrounds nerve cells. When this nerve covering is damaged, nerve impulses are slowed down or stopped. The condition is a progressive disease, meaning the nerve damage (neurodegeneration) gets worse over time. How quickly MS gets worse varies from person to person. The nerve damage is caused by inflammation. Inflammation occurs when the body's own immune cells attack the nervous system. Repeated episodes of inflammation can occur along any area of the brain and spinal cord.
Researchers are not sure what triggers the inflammation. The most common theories point to a virus or genetic defect, or a combination of both. MS is more likely to occur in northern Europe, the northern United States, southern Australia, and New Zealand than in other areas. Geographic studies indicate there may be an environmental factor involved. People with a family history of MS and those who live in a geographical area with a higher incidence rate for MS have a higher risk of the disease.