Sanofi/Bayer’s multiple sclerosis drug alemtuzumab is ‘the best treatment for MS’, according to UK researchers.

The Lancet has published new data from two Phase III trials, evaluating the efficacy and safety of the anti-CD52 monoclonal antibody alemtuzumab for a two-year period in patients with multiple sclerosis. Both trials have shown highly positive results in what is a tricky condition to gain headway in.

Alemtuzumab is licensed to treat leukaemia, where it has the brand name Campath, but has been used off-label in patients with multiple sclerosis for many years.

The results show that when compared with Merck Serono's established MS injectable drug Rebif, alemtuzumab was found to significantly reduce relapse rate not only in previously untreated patients with relapsing-remitting multiple sclerosis, but also in those who had relapsed despite first-line treatment.

Notably, in the latter group, the risk of sustained accumulation of disability was also decreased. These trials have been keenly awaited by clinicians and patients wishing to establish evidence for this practice, according to an editorial in the science journal.

Dr Alasdair Coles, from the University of Cambridge who worked on the trials, said: “Although other MS drugs have emerged over the last year, which is certainly good news for patients, none has shown superior effects on disability when compared to interferon except alemtuzumab,” adding that “no other treatment has led to improvements in disability”.

He told the BBC: “It is certainly the most effective MS drug, based on these clinical trials, but this is definitely not a cure.”

But the efficacy of alemtuzumab, as with all drugs, comes with a price of adverse events: in these studies, they include infusion-associated reactions, infections, and autoimmune diseases - mainly thyroid disorders but also immune thrombocytopenia, both of which require careful monitoring and management.

High cost?

Sanofi recently withdrew the drug from the USA and European Union, and submitted applications for approval in relapsing multiple sclerosis treatment from both regulators, this time under the brand name Lemtrada.

However, there is concern that with a licence for multiple sclerosis, the cost of alemtuzumab could rise and might become too expensive for many patients and health systems, The Lancet notes. This is because good treatments for MS are few and far between, and many established drugs on the market cost between £10,000 and £20,000 per patient per year; if alemtuzumab is better than these, then it can use the market justifiably charge more.