Thursday, May 19, 2011
A number of new multiple-sclerosis medications are beginning to hit the market that promise to make it easier for patients to control flare-ups of the disease and slow its progression.
The drugs, designed to be taken orally, represent a new generation of treatment for MS. Currently, people with the disease can choose from a range of drugs that are administered by injection.
Physicians say many people are reluctant to stick themselves with a needle and would be more comfortable taking a pill once or twice a day. This could encourage a greater number of MS patients to take medication as needed and could spur earlier treatment, which is important since disability from MS is cumulative.
Cost of the new drugs is expected to be high. Novartis AG's Gilenya, so far the only oral MS drug on the market, is priced at about $48,000 a year; the drugs still being developed are expected to cost about the same. That's higher than injectable drugs currently in use, which cost roughly $40,000 a year. Health insurers often pick up most of the expense of MS drugs.
There is a "tremendous desire" among MS patients to begin using oral treatments because of their ease of use, says Joseph Herbert, director of the MS Care Center at NYU Langone Medical Center. Still, he says, many physicians are being cautious about prescribing the oral drugs because their side effects can't be fully assessed until they are used widely for an extended period of time.
Among its side effects, Gilenya can increase a person's risk of infection and potentially lead to toxicity of the liver and an eye disease called macular edema, clinical trials have shown. Some of the oral drugs still in development are expected to have somewhat milder side effects.
The current injectable drugs have generally less severe side effects, including injection-site irritation and flu-like symptoms, although some patients incur more serious problems such as liver damage.
Elizabeth Fuchs, an MS patient on Staten Island, N.Y., began taking Gilenya about two months ago. The 49-year-old was diagnosed with MS about 12 years ago and had tried several injectable medications. Avonex, made by Biogen Idec Inc., required weekly intramuscular injections. She later switched to Copaxone, from Teva Pharmaceutical Industries, which is administered with a daily subcutaneous injection.
"It is just much easier to put a pill in your mouth and take a glass of water," Ms. Fuchs says. Not having to inject herself has made her feel more positive about having MS and even allows her to forget she has the disease, she says.
There is no cure for MS, a chronic, inflammatory condition that occurs when the body's immune system attacks its own central nervous system.
MS, which affects about 400,000 people in the U.S., is marked by symptoms such as vision problems, limb numbness and paralysis. Women are more likely to get the disease than men, and genetic factors may make certain individuals more susceptible, according to the National Multiple Sclerosis Society.
Gilenya, which received Food and Drug Administration approval last fall, is thought to work by reducing the quantity of circulating immune cells that can cause damage in an MS attack. More than 6,500 patients are taking the drug, according to the most recent Novartis data.
Recent data from large clinical trials of other drugs being developed, including Biogen Idec's BG-12, Teva Pharmaceutical's laquinimod, and teriflunomide, from Sanofi-Aventis SA, show they are also effective at controlling MS flare-ups and slowing the progression of disability from the disease. More data on the drugs are expected later this year and, assuming FDA approval, they could all be on the market in late 2012.
The success of any of these drugs isn't guaranteed. Another oral MS drug, Merck KGaA's cladribine, was rejected by U.S. and European regulators earlier this year amid long-term safety-related questions, including an increased cancer rate in patients taking the drug. The company says it remains committed to gaining approval.
Another drug, Biogen's Tysabri, was approved in 2004 but was later temporarily pulled from the market after it was linked to a rare brain infection. Tysabri, administered by intravenous infusion, became available again in 2006 but is limited mainly to patients who don't respond to other treatments.
A recent analysis by Novartis showed that Gilenya reduced relapses among MS patients by 54%. Disability progression was reduced by 30%, using a standard measurement of this process.
Biogen's BG-12 drug reduced MS flare-ups by a similar amount as Gilenya, but with fewer side effects. Smaller reductions in flare-ups were seen in trials with patients using laquinimod (23%) and teriflunomide (31%).
By comparison, Avonex, one of the leading injectable drugs, has been shown to reduce MS flare-ups by 32% and disability progression by 37% over two years.
Physicians say MS cases vary greatly and some drugs won't work for certain patients. Also, it is difficult to directly compare two different clinical trials.
NYU's Dr. Herbert says it is a challenge to get patients to use prescribed injectable therapies. Oral medications' ease of use should increase the number of patients who use the drug as required, he says. This also is expected to encourage some patients, especially those in the initial stages of MS, to begin therapy before the disease advances significantly.
"The data certainly suggest that starting therapy earlier does slow down the progression of the disease," says Timothy Coetzee, chief research officer for the National Multiple Sclerosis Society.
Doctors say they aren't likely to recommend a patient switch to one of the new oral drugs if an injectable drug currently in use is working. Although the ease of taking a pill, rather than an injection, is important, effectiveness of a given drug takes precedence. Patients who switch treatments run the risk of the new drug not being the right fit for them, says Mayo Clinic neurologist Mark Keegan.
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