Oral Drug Treatments for Multiple Sclerosis on the Horizon

If you are living with multiple sclerosis (MS) and currently receive self-injectable or IV- infused disease modifying drugs, your future treatment options could come in the form of a pill.

Earlier this year, Merck Sereno, a division of German-based pharmaceutical and chemical company Merck KGaA, reported positive results for a two-year Phase III clinical trial using its proprietary oral formulation of cladribine to treat patients with relapsing-remitting forms of MS. Cladribine is a small molecule that may interfere with the behavior and the proliferation of certain white blood cells, particularly lymphocytes, which are thought to be involved in the pathological process of MS.

The trial, called CLARITY (CLAdRIbine Tablets Treating MS OrallY), consisted of two treatment groups (1,326 randomized patients) and assessed different dose regimens of cladribine tablets. Researchers found that annual short-course treatment with cladribine tablets led to "a significant reduction in the rate of clinical relapses, disability progression and brain lesions, as well as a significant increase in the proportion of patients who remained relapse-free."

disability viewsMerck Sereno reported that over the two-year period of the study, 80% of the patients treated with the low dose regimen of cladribine tablets and 79% of the patients treated with the high-dose regimen experienced no clinical relapse, compared with 61% of the patients from the placebo group (p<0.001 for both dose regimens). Therefore, the relative risk to relapse in patients treated with cladribine tablets was approximately half of that seen in patients on placebo.

In late July of 2009, Merck Sereno filed for a European license for cladribine. If the drug gains regulatory approval with no setbacks, it could reach the market by mid-2010, ahead of its rivals, including Swiss drug manufacturer Novartis, who is also currently conducting Phase III clinical trials for an oral MS drug called Fingolimod (FTY720). Previous trials have shown FTY720 to be effective in preventing MS relapses in more than 60% of patients that were given the pill for three years.

There are a number of other pharmaceutical companies also vying to produce the first oral treatment for MS, including Teva Pharmaceutical (Laquinimod), Biogen Idec (BG-12), and Sanofi-Aventis (Teriflunomide). However, experts estimate that these manufacturers may still be a few years behind Merck Sereno and Novartis in acquiring Food and Drug Administration (FDA) approval.

Currently, there are six FDA-approved disease modifying MS drugs on the market:

A majority of these drugs must be administered by subcutaneous or muscle injection every day or every other day of the week, except for Novantrone, which is administered four times per year by IV infusion in a medical facility. An oral drug would be a welcomed alternative to many individuals with MS.