Sanofi says Lemtrada helps MS patients in study
* Lemtrada significantly reduces relapses vs Merck's Rebif
* Sanofi aims to file for regulatory approval in Q1 2012
PARIS Oct 22 (Reuters) - French drugmaker Sanofi said on Saturday that its experimental multiple sclerosis drug Lemtrada worked better than an older drug sold by competitor Merck KGaA at keeping patients free from relapses.
New data from a late-stage trial showed that 78 percent of patients treated with Lemtrada remained relapse-free for two years, compared with 59 percent using Rebif, an older multiple sclerosis drug sold by Germany's Merck.
Lemtrada is a key experimental product at Sanofi's Genzyme unit. The fortunes of the drug are closely watched by holders of Genzyme Contingent Value Rights certificates issued to shareholders as part of the U.S. company's takeover deal.
CVRs represent an extra fee holders will receive if Lemtrada hits certain targets or when Genzyme meets other milestones.
The commercial potential of the drug, already sold under the brand name Campath as a leukaemia treatment, was a key bone of contention between Sanofi and Genzyme during takeover talks.
Multiple sclerosis, which affects 2.5 million people worldwide, is a chronic and progressive disease that attacks the central nervous system.
Previously published data from the same late-stage study were mixed. Although Lemtrada was found more effective than Rebif at preventing relapses, it did not prevent the disease from becoming disabling, as it had in earlier trials.
The results of the latest late-stage trial showed that side-effects, including respiratory and urinary tract infections, were mild to moderate, Sanofi said.
Serious adverse events were similar between Lemtrada and Rebif, Sanofi said, with 18.4 percent of patients on Lemtrada suffering from side effects that included autoimmune disorders compared to 14.4 percent in patients taking Rebif.
The drug's prospects should become clearer once the results of another late-stage trial are published by year-end. The study is comparing Lemtrada with Rebif in multiple sclerosis patients who have relapsed while on therapy.
Sanofi plans to submit Lemtrada for U.S. and European Union marketing approval in the first quarter of 2012. The drug, if approved, will face competition from Novartis's Gilenya.
(Reporting By Elena Berton; Editing by Helen Massy-Beresford)