PARIS (Reuters) - A U.S. law firm is launching a class action against France's Sanofi over what it calls misleading statements on the safety and efficacy of its multiple sclerosis drug Lemtrada.
Sanofi acquired Lemtrada when it bought U.S. biotech firm Genzyme for $20.1 billion in 2011. The drug's prospects took center-stage in a drawn-out takeover battle and led to a deal in which Genzyme shareholders received listed contingent value rights (CVRs) linked to Lemtrada's future success.
Law firm Lieff Cabraser Heimann & Bernstein, LLP said on Friday it was bringing litigation on behalf of all purchasers of the CVRs between March 6, 2012 and November 7, 2013.
The firm alleged that over this period, Sanofi and some of its senior executives made false and misleading statements about its business and the prospects for Lemtrada, and misled investors over the design of its clinical trials on the drug.
A spokesman for Sanofi said the company does not comment on pending litigation.
The complaint comes after U.S. Food and Drug Administration (FDA) experts voiced concerns last month over Lemtrada's safety and the quality of its clinical studies, prompting CVRs on the drug to shed over 60 percent of their value in one day.
Lemtrada, an injectable treatment also known as alemtuzumab, is one of Sanofi's two new drugs for MS, an autoimmune disease that attacks the central nervous system and affects more than 2 million people worldwide.
The drug was approved by European regulators in September and the FDA is expected to rule by December 27 on whether to approve the treatment for marketing in the United States, the world's biggest pharmaceutical market.
(Reporting by Natalie Huet; Editing by Mark Potter)