April 16, 2008 -- Seventy percent of multiple sclerosis patients taking the experimental drug FTY720 -- fingolimod -- were relapse free after three years of daily treatment.
The finding comes from an extended phase II clinical trial in which all patients receive the immunity-suppressing drug. Researchers Giancarlo Comi, MD, of San Raffaele Hospital in Milan, Italy, reported the findings at this week's meeting of the American Academy of Neurology in Chicago.
"The first-line treatments for MS ... reduce the relapse rate by only about 30%, so this is a significant development for people with MS," Comi says in a news release.
All current MS drugs must be administered by injection or infusion -- a huge disadvantage for patients, says neurologist Orly Avitzur, MD, medical advisor for Consumer Reports. Avitzur was not involved in the fingolimod study.
"This drug is completely different from any other on the market for MS," Avitzur tells WebMD. "It is the first oral MS drug to get this far, and if it is successful in large-scale clinical trials, it will make a huge difference in quality of life for MS patients."
In the phase II study, 173 patients with the relapsing form of MS (a type of MS that repeatedly relapses and has periods of recovery in between) received fingolimod for three years. More than 67% of the patients were free of relapses after three years, with an annual relapse rate of 0.2%, says Shreeram Aradhye, MD, vice president and senior global medical program director for Novartis, the company developing fingolimod.
"When you look at all the biologic treatments [medications that target the immune system to reduce the frequency and severity of attacks and reduce lesions within the brain] for MS, this 0.2% annualized relapse rate seems to be a new benchmark," Aradhye tells WebMD. "This was complemented by the encouraging observation that 89% of patients at year three have no evidence of inflammation in MRI brain scans [a sign of MS progression]."
Fingolimod Safety Good So Far, but Not Assured
So far, the most common side effects of fingolimod have been head colds, headache, and fatigue. But there have also been a few cases of skin cancer, which has also been reported in patients taking Tysabri, an approved MS drug.
Like Tysabri, fingolimod suppresses the autoimmune responses thought to cause MS. In MS, haywire T lymphocytes -- the cellular generals of the immune system -- order attacks on the myelin sheaths that surround and protect the brain cells.
Tysabri is an engineered antibody that inactivates T cells. Fingolimod is a molecule that deprives T cells of the signal they need to leave lymph nodes, effectively stranding them outside the brain. It was originally designed to help prevent organ rejection in transplant patients, but that didn't work out very well, Aradhye says.
"Fingolimod is a gentle immunomodulator, which for a disease like MS is actually better than a strong one," Aradhye tells WebMD. "We have not seen anything to suggest that it results in serious opportunistic infections. Fingolimod is not destroying the lymphocytes, just keeping them away. Lymphocytes left in body tissues are able to do what they normally do. And while we have seen mild infections -- minor colds and coughs -- infection rates have not increased over time."
Even so, Aradhye warns that fingolimod is a potent inhibitor of immune responses and that patients are being watched carefully as they continue in the study. Three large phase III, placebo-controlled clinical trials are beginning, with a 1,000-patient U.S. study still recruiting patients. All patients in these studies will receive regular examinations by a dermatologist to ensure that if skin cancers occur, they will be detected early.
And researchers will continue to see what happens to patients in the current study as they continue on the drug.
"We are developing a new molecule, with a new biology, so it is important to see what happens, in terms of safety, in the core study over time," Aradhye says.
Aradhye hopes to have early results from phase III studies by early 2009 -- and hopes to have enough data to file for FDA approval by the end of that year.
"It is a privilege to work on something with the potential to be an oral agent with great efficacy for MS," he says. "We hope to have the data available in good time. But first we have to get though the phase III program."
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