FDA Says Sanofi MS Drug Lemtrada Can Cause Stroke, Artery Lining Tears

WASHINGTON, D.C. — The Food and Drug Administration has warned that Sanofi’s multiple sclerosis drug Lemtrada (alemtuzumab) has caused strokes and tears in the lining of arteries in the head and neck in certain patients following intravenous infusion.

In a Nov. 29 drug safety communication, the agency says it added new warnings about those risks to the drug’s label — including the boxed warning — and the patient medication guide. Most often, the problems occur within one day after receiving treatment, but can occur a few days after treatment, the FDA says.

“A stroke can occur when blood flow …