Sanofi’s Genzyme unit is pulling its leukaemia drug Campath prior to its launch as a multiple sclerosis treatment named Lemtrada.

Designed to prevent the off-label use of Campath, a Genzyme spokesman confirmed that the withdrawal is currently under way in selected European countries and will become effective in the US as of 4 September 2012.

Genzyme is seeking approval for the drug, which is taken less frequently and in lower doses than Campath, having submitted it to European and US health regulators in June 2012.

Should the company receive approval, the drug could be launched as early as next year, reports BioCentury.

Despite the withdrawal, Campath will continue to be available to patients through patient access programmes in the countries where it had been available, with a Genzyme spokesman further adding that the company will provide the drug for free where permitted.

Speaking on the company’s request for approval, Genzyme president David Meeker said; "There remains a large unmet treatment need for patients living with active disease and we believe that Lemtrada, given its efficacy and unique dosing schedule, has the potential to transform the lives of patients with MS."

Genzyme’s request for approval is based upon two Phase III studies in which Lemtrada was proven to be superior to current MS treatment Rebif on clinical and imaging endpoints, whilst also reducing a patient’s relapse rate.

Some patients treated with Lemtrada were also shown to be more than twice as likely to experience a sustained reduction in disability over two years than patients who received Rebif.