A drug now used to treat leukemia was successful in treating relapsing-remitting multiple sclerosis, beating out the primary MS drug, interferon beta 1a, in two clinical trials reported Wednesday. The drug was also more effective in treating patients who had failed treatment with current drugs. The new drug, called alemtuzumab, could be approved for marketing as early as this year. The drug has some relatively severe side effects, but clinicians are confident those can be controlled with careful monitoring of patients. Many physicians have already been prescribing the drug to their patients, but the outcome of the new trials has been widely anticipated.
Multiple sclerosis affects about 400,000 people in the United States. The precise cause is not known, but symptoms occur when the body's immune system attacks the myelin sheaths surrounding nerves -- in effect, short-circuiting the nerves. Characteristic symptoms include impairments of vision, movement, balance, sensation, bladder control and, eventually, memory and cognition. In the relapsing-remitting form, symptoms appear sporadically, then fade away, either partially or completely. There is no cure for the disease.
Two teams of researchers, each headed by Dr. Alastair Compston of the University of Cambridge, conducted separate two-year clinical trials of the drug, the results of which were reported Wednesday in the medical journal Lancet. In one trial, called CARE MS I, researchers compared alemtuzumab to inteferon beta 1a, the primary existing treatment for MS, in 563 patients who had not yet received any treatment for the disease. About 40% of patients who received interferon relapsed within two years, compared with 22% of those who received the new drug.