"At last, we can treat a whole lot of MS people that we've not been able to treat before," Dr. Loren Rolak of the Marshfield Clinic in Wisconsin and a spokesman for the National MS Society, told CNN. That would include people who are afraid of needles, those who are resistant to existing drugs or are tired of their side effects and those who dislike the needle sticks.

MS is a disease in which the body's own immune system attacks the protective layer of myelin around nerve fibers, producing short circuits. Symptoms include visual disturbances, difficulty walking, fatigue, and loss of coordination, sensation, and bowel and bladder control. About 85% of the 400,000 Americans with the disease have the relapsing-remitting form, in which attacks on the body are followed by periods of remission -- although each relapse typically leaves the body more damaged.

Fingolimod works by preventing the release of the white blood cells that attack the myelin. That also leaves the user open to infections, however. Two studies reported in the New England Journal of Medicine in January showed that fingolimod reduced relapses by half. But the studies also showed that, at the highest dose used, 1.25 milligrams, the drug increased susceptibility to infections, cardiovascular effects, swelling of the retina and elevated levels of liver enzymes. The panel recommended approval of an 0.5-milligram dosage because it seems to have nearly the same benefits as the higher dose, but far fewer side effects. The panel also recommended that Novartis conduct a clinical trial using half that dose.

The FDA said the company would also be required to conduct a post-approval safety study to monitor for adverse effects of the drug.

The panel also recommended that the drug not be restricted to those who had failed other treatments, indicting it could be used as a first-line drug. To the disappointment of Novartis, however, the group also recommended that patients receiving the drug for the first time be monitored closely for six hours to watch for side effects. That might require them to stay in the physician's office for nearly a day.

Because the drug can be taken orally, some experts predict that it will be a blockbuster drug for Novartis, with annual sales of more than $1 billion.