Genzyme's multiple sclerosis drug, Lemtrada (alemtuzumab) has shown positive interim results in the second year of its extension study.

In these studies, Lemtrada was given as two annual courses, one at the start of the study and other 12 months later. The study found that, relapse rates and sustained accumulation of disability remained low among patients who had previously received the drug in any of the Phase III CARE-MS I and CARE-MS II studies. No new safety signals were identified.

"These extension study results provide further evidence of the prolonged efficacy of Lemtrada on both relapses and disability. The majority of patients continued to experience reduced disease activity, even though their last Lemtrada treatment was three years earlier," said Dr Alasdair Coles, senior lecturer, Department of Clinical Neurosciences, University of Cambridge.

More than 90 percent of the patients who were treated with Lemtrada in the Phase III trials enrolled in the extension study.

The results of the study will be presented at the European Committee for Research and Treatment in Multiple Sclerosis meeting in Boston.