Campath as medication was first approved for B-cell chronic lymphocytic leukemia in 2001. It is marketed by Genzyme, which acquired the worldwide rights from Bayer AG in 2009. Genzyme was bought by Sanofi in 2011. In August/September 2012 Campath was withdrawn from the markets in the US and Europe. This was done to prevent off-label use of the drug to treat multiple sclerosis and to prepare for a relaunch under the trade name "Lemtrada", with a different dosage aimed at multiple sclerosis treatment, this is expected to be much higher-priced.