LONDON — Four years ago, Karen Ayres was paralyzed from the neck down by multiple sclerosis.

But then she started receiving an experimental combination of drugs. And within weeks, she herself was walking — right out of the hospital.

That was in 2002. And Ayres, now 28 and studying for a doctoral degree in health and psychology, hasn't had any relapses of her disease since.

She was among 27 patients with aggressive MS who were treated with a course of the anticancer drug mitoxantrone plus Copaxone, which is used to treat relapsing MS.

Like Ayres, many of the other patients experienced results so remarkable that some MS experts, while expressing caution, are now taking a second look at the preliminary experiment. A three-year controlled study is being launched at 10 centers across the United Kingdom to further investigate the drug combination. The results of the initial trial, led by Dr. Mike Boggild at the Walton Centre in Liverpool, will be published next month in the Journal of Neurology.

The cause of nerve-damaging multiple sclerosis is unknown and there is no cure. The most common form causes periodic flare-ups of symptoms, which include trouble seeing and walking. Mitoxantrone is so powerful that it is potentially toxic and can only be used safely in the short term. Boggild and his colleagues combined it with Copaxone — a slow-acting drug.

What happened was dramatic. "Patients who were just the worst of the worst did remarkably well," Boggild said.

Patients were first given a limited course of mitoxantrone, before being started on Copaxone, usually a few months later. While the study has generated some impressive results, many experts say more time is needed.

"It's a small study with no control group," says Dr. Robyn Wolintz, co-director of the MS Center at Maimonides Medical Center in New York. "They also gave different people different doses of mitoxantrone, and that's not standard.

Still, some experts believe Boggild and his colleagues have stumbled upon a valid hypothesis. For people with particularly aggressive MS — some 5 percent to 10 percent of MS patients — the treatment may provide some hope.