Sanofi ($SNY) plans to buy back up to $152 million in contingent value rights linked to last year's buyout of Genzyme. The French drugmaker says it would purchase about 30% of the CVRs, which pay off if certain Genzyme sales targets are met. The move is seen as a sign that Sanofi is confident that the multiple sclerosis drug Lemtrada will be as lucrative as hoped. Report