Sanofi and its subsidiary Genzyme have reported new results from the CARE-MS I trial, comparing the investigational drug Lemtrada (alemtuzumab) to Rebif (high-dose subcutaneous interferon beta-1a) in patients with relapsing-remitting multiple sclerosis (MS).

The findings from the first of two randomised, Phase III clinical trials showed that 78% of patients treated with alemtuzumab remained relapse-free, and 55% reported a reduction in relapse rate compared to interferon beta-1a over two years of study.

An improvement in Multiple Sclerosis Functional Composite scores was also observed in alemtuzumab-treated patients, compared with those treated with interferon beta-1a.

Alastair Compston, head of the Department of Clinical Neurosciences at the University of Cambridge in UK, said that the CARE-MS I trial confirmed that patients treated with alemtuzumab showed a reduction in disease activity over the first two years of observation.

"This data support the efficacy profile and potential that alemtuzumab offers for patients with relapsing-remitting MS requiring a more effective option than currently available therapies," Compston added.

The other Phase III trial, CARE-MS II, which is currently underway, is assessing alemtuzumab against interferon beta-1a in relapsing-remitting MS patients, and the results are likely to be published in the fourth quarter of 2011.

The company is planning to register for US and EU approval of alemtuzumab in relapsing MS during the first quarter of 2012.