Campath is approved to treat B-cell chronic lymphocytic leukemia. The company had to halt its study using the drug for treating MS in September 2005, after three patients developed a condition called thrombocytopenic purpura, or ITP. Altogether, 6 patients have been diagnosed with ITP, which led to the death of one patient. Genzyme said it is working with clinical investigators and regulators to address the issue and continue the study.
The interim results from the halted Phase II clinical trial show that patients in the study experienced a 75% reduction in risk for relapse after two years of follow up. It also showed that patients experienced a 65% reduction in the risk of clinically significant disability.
The 334-patient study compared Campath with Rebif, which is co-marketed by Geneva-based Serono and New York-based Pfizer. Worldwide Rebif sales totaled $689 million during the first half of 2006, according to Serono. Shering AG has the exclusive worldwide marketing and distribution rights to Campath, which was launched in June 2001 in the United States and Europe.
Shares of Genzyme rose almost 3% on the Nasdaq in midday trading following the announcement.