Two clinical trials published in The Lancet have shown that a monoclonal antibody used to treat leukaemia is also an effective therapy for relapsing–remitting multiple sclerosis (Los Angeles Times, 31 Oct 2012).

The Phase III trials examined the efficacy of alemtuzumab — which targets CD52 and depletes mature lymphocytes — in patients who were newly diagnosed with multiple sclerosis or who had failed to respond to other standard therapies. The researchers found that alemtuzumab was significantly more effective than standard interferon-β therapy in preventing disease relapse and could prevent the accumulation of new disabilities. According to Dr Alasdair Coles from the University of Cambridge, UK, who was involved in the trials, this is “good news for patients”. He says the trials suggest that alemtuzumab is the “most effective MS [multiple sclerosis] drug”, although he cautions that this is still “not a cure” (BBC News, 1 Nov 2012).

But a storm has been brewing that threatens to overshadow these encouraging results. Although alemtuzumab is not yet licensed for multiple sclerosis, neurologists have been aware of its benefits for some time and prescribe it 'off-label' to some patients. However, the drug company that markets alemtuzumab for the treatment of leukaemia has recently withdrawn it from the US and British markets. They are seeking permission (which looks likely to be given) to market it under the new brand name Lemtrada for multiple sclerosis. There is concern that this will prevent further access to alemtuzumab for patients currently receiving the drug off-label. Furthermore, doctors expect a hefty hike in the cost of the new version of the drug once it is licensed for use in multiple sclerosis (The Independent, 1 Nov 2012).

An editorial in The Lancet argues that it will be important to keep alemtuzumab “accessible and affordable if its early success in these trials proves to be of enduring value”.