A chemical that can be used as a food additive, caused serious skin infections after people sat on sofas treated with it and was approved as a psoriasis treatment in Germany 15 years ago, may prove to be a viable treatment option for people with the relapsing-remitting form of multiple sclerosis (MS).
Dimethyl fumarate - also known so far as BG-12 - could be another weapon in a neurologist's arsenal to treat the disease, if the drug is approved. Based on the results of two large studies published in the New England Journal of Medicine, experts believe this is likely.
More than 2 million people around the world live with MS, a disease where the body's immune system attacks the patient's central nervous system and destroys the myelin, or sheath, protecting nerve cells. Most people are diagnosed between the ages of 20 and 50, and more women than men are affected, according to the National MS Society. As the disease progresses, it can become quite debilitating, leading to numbness and difficulty walking and seeing among many other symptoms.
"Relapsing MS is a disease that we have treatments for, but they're really on two ends of the spectrum," says Dr. Robert Fox, a neurologist at the Mellen Center for MS at the Cleveland Clinic. "We have injection treatments that have modest efficacy. They reduce relapses by about 30%.
"And we have very effective therapies, but they are infusion therapies and they have risk - risks of a brain infection - that may be fatal," Fox says. "This new treatment offers the opportunity for sort of the best of both worlds, in that it has very good efficacy, but it's in the form of a pill and appears to have much reduced risk than other therapies."
Fox, who is the lead author of one of the studies, says both studies published Wednesday were designed in the same way so their results could be examined together. Both were large trials involving more than 1,400 patients in many countries and both compared BG-12 to a placebo - a common scenario when seeking drug approval.
He says both studies showed BG-12 reduced the number of relapses, reduced the number of lesions or scars on the brain and progression of disability and was more effective than standard injectable MS drugs.
Both studies found BG-12 was well tolerated and seems to be safe. They looked at taking the pill two and three times day. Fox says between the two studies, taking the pill three times a day wasn't significantly better than twice a day, which is why the FDA drug approval application only refers to twice daily dosing.
Timothy Coetzee, chief medical research officer for the National MS Society, says the study results look very promising. He says it's a "good news story for people who live with MS" because the pill has been shown to be effective in reducing the number of relapses. Coetzee says it's too early to say BG-12 is superior to other MS drugs in pill forms, as studies haven't been done yet.
Based on these results of these two studies, Fox and Coetzee believe the FDA will approve the drug. Only after that happens will we know what name manufacturer Biogen Idec will sell BG-12 or dimethyl fumarate under, as well as its price. The FDA has until December 28 to make a decision.
If this happens, BG-12 would be the third MS drug in pill form approved by the FDA. Just last week, the agency approved another MS drug in pill called Aubagio. It too was shown to be effective in reducing the number of relapses, slowing down disease progression and reducing the number of brain lesions. The first pill, Gilenya, was approved two years ago.
Like any drug, these new MS drugs in pill form have their pros and cons. Each of these pills "targets a different part of the immune system in a very specific manner," says Coetzee, which may influence what a patient may be prescribed and how they react to each drug.
Side effects also are a consideration. Since people as young as 20 could be diagnosed with this disease that affects 2.1 million people worldwide, women who want to get pregnant or who are pregnant would not be a candidate for Aubagio because it could cause severe birth defects.
Patients taking Gilenya have to be monitored for the possibility of their heart rate slowing down. Earlier this year, health agencies in the United States and Europe were reviewing safety concerns after 11 deaths were linked to patients taking Gilenya.
BG-12 is not without side effects. The two-year clinical trials showed common side effects including skin flushing and some nausea, vomiting and diarrhea - usually in the first month. After that, Fox says, patients did quite well. What hasn't been seen in patients so far is an increased risk of infections or cancer with this drug, says Fox.
And then there are still the older injectable and infusion drugs that may still work very well for those patients taking them. Coetzee believes some patients may want to wait until these drugs stop being effective and then shift to another option.
Cost could be another