New oral drugs in development for MS
Open Door - May 2007 page 11
Following the discussion of research into treatments for primary progressive MS in the last issue of Open Door (read the article), this time we look at potential new treatments for relapsing/remitting MS.
The primary target for treatments for relapsing/remitting MS is to prevent continuing damage to the central nervous system. The race is on to develop the first oral disease modifying treatment for MS, offering a clear advantage over the current disease modifying drugs, all of which are injected.
It is important to remember that not all these drugs will complete the development process and be licensed for general use (or be recommended by NICE or SMC). It is also unlikely that any of these new treatments will be available before 2011.
Fingolimod (FTY720)
Currently the front runner, fingolimod appears to act by reducing the levels of circulating T cells (white blood cells in the immune system) and keeping them in the lymph nodes where they can't contribute to damage to the myelin sheath around nerves.
A six month, phase II trial of fingolimod involving 255 people with relapsing/remitting MS found active MRI lesions were significantly reduced when compared to placebo. More people in the treatment group stayed relapse-free.
An 18 month extension of the original study, in which those previously taking placebo switched to fingolimod, confirmed these results, with up to 77% of those taking fingolimod remaining free of relapses over two years.
Phase III trials are underway.
BG00012
BG00012 appears to have an immunomodulatory mechanism of action and is similar to a drug currently used to treat psoriasis, an autoimmune condition which affects the skin and joints.
In a phase II study, different doses of BG00012 were compared to placebo in people with relapsing/ remitting MS over 24 weeks of treatment. BG00012 significantly reduced MRI-detectable brain lesion activity. A 32% reduction in relapse rate was also observed but could not be considered significant since this measure was not included in the study design.
Phase III clinical trials are underway.
Teriflunomide
Teriflunomide is thought to prevent the interaction of cells in the immune system involved in damage to the myelin sheath.
Two different doses of teriflunomide were compared to placebo in people with relapsing/remitting MS or secondary progressive MS with relapses for 36 weeks. Both doses were associated with reduced numbers of active MRI lesions and the higher dose was associated with a significantly smaller increase in disability compared to placebo.
A phase III study is currently underway.
Cladribine
Cladribine is currently licensed to treat certain forms of leukaemia and appears to interfere with the behaviour and proliferation of lymphocytes.
Cladribine is being evaluated in a phase III study, known as CLARITY (CLAdRIbine Tablets Treating MS OrallY).
Laquinimod
A recent phase II study of oral laquinimod concluded that it is well tolerated and effective in suppressing development of active MRI lesions in relapsing MS. Treatment over six months resulted in a 30% decrease in MRI disease activity. People with disease activity at the start of the study showed a decrease of more than 40%.
No phase III studies have been announced as yet.
In the next issue of Open Door we will be looking at some of the other new treatments in development.
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