French drugmaker Sanofi's Genzyme unit is pulling its cancer drug Campath/MabCampath from markets on both sides of the Atlantic in order to optimise the pending launch of the drug as a treatment for multiple sclerosis, according to reports.

The company has decided to concentrate on marketing the monoclonal antibody - which has the generic name alemtuzumab - for MS instead in a different dose and under the trade name Lemtrada, in a bid to stop doctors from prescribing the drug off-label for the condition and equalise its price with market rivals.

Sanofi - which acquired Campath through its $20.1 billion takeover of Genzyme last year - filed Lemtrada for MS in both the USA and Europe in June this year.

Its submissions centred on two Phase III studies which demonstrated that the drug was superior to Merck KGaA's blockbuster Rebif (interferon beta-1a) on clinical and imaging endpoints, including a reduction in relapse rate.

And in another promising performance, data presented at a medical congress earlier this year showed that some patients with preexisting disability treated with Lemtrada were more than twice as likely to experience a sustained reduction in disability over two years than patients given Rebif.

Sanofi is reportedly trying to prevent the off-label use of the drug for MS, which could steal some of Lemtrada's thunder and thereby prevent it from achieving the sales milestones associated with the "contingent value right" inked into its deal to buy Genzyme, under which shareholders are entitled to payments linked to the success of the product in the MS setting.

Confidence in approval?

"We think that this stoppage shows Sanofi's confidence in the approval of Lemtrada in multiple sclerosis," commented Bryan Garnier analyst Eric Le Berrigaud, forecasting sales for the drug of $400 million in 2018, reports Reuters.

According to BioCentury, the US withdrawal of Campath for the treatment of B cell chronic lymphocytic leukemia, sales of which have been in decline for some years, will take place at the beginning of September, while in Europe it was pulled back earlier this month. 

Genzyme acquired worldwide rights to alemtuzumab from Bayer AG back in 2009, under which the German drugmaker holds an option to co-promote the product for MS.