Genzyme, a Sanofi company (EURONEXT: SAN and NYSE: SNY), announced today the publication of results from the LEMTRADA ™ (alemtuzumab) CARE-MS I and CARE-MS II pivotal studies in patients with relapsing-remitting multiple sclerosis (MS) in the November 1, 2012 online issue of The Lancet. In CARE-MS I and CARE-MS II, LEMTRADA was significantly more effective at reducing annualized relapse rates than the active comparator Rebif ® (high dose subcutaneous interferon beta-1a), and more patients on LEMTRADA were relapse-free at two years. In addition, in CARE-MS II, accumulation of disability was significantly slowed in patients given LEMTRADA vs. Rebif. Further, patients treated with LEMTRADA were significantly more likely to experience improvement in disability scores than those treated with Rebif, suggesting a reversal of disability in some patients. “There is a tremendous unmet need for treatments that address the progression of disability that people living with multiple sclerosis can experience,” said Genzyme President and CEO, David Meeker, MD. “Genzyme set a new standard by comparing LEMTRADA exclusively to an approved treatment in all of our studies.Publication of these findings by The Lancet highlights the importance of these results to the MS community.”CARE-MS I and CARE-MS II Efficacy Results CARE-MS I and CARE-MS II ( Comparison of Alemtuzumab and Rebif ®Efficacy in Multiple Sclerosis) are randomized Phase III studies comparing the investigational treatment alemtuzumab to a standard of care MS treatment, Rebif, in patients with relapsing-remitting MS who were naïve to prior treatment or who had relapsed while on prior therapy, respectively. The results from these trials for LEMTRADA were superior to Rebif on clinical and imaging endpoints, including a reduction in relapse rate and are published in full in The Lancet. “The observed efficacy in these and earlier clinical studies indicates the potential, following regulatory approval, for alemtuzumab to become a transformative therapy amongst the various MS treatment options that are currently available,” said Professor Alastair Compston, Chair of the Steering Committee overseeing the conduct of the study, senior author of both manuscripts, and Professor of Neurology, University of Cambridge, UK. In both studies, LEMTRADA was significantly superior to Rebif in reducing relapses. In CARE-MS I, 78 percent of patients treated with LEMTRADA remained relapse-free for two years, providing statistically significant improvement over Rebif (77.6 percent vs. 58.7 percent, p<0.0001). In the CARE-MS II trial, 65 percent of patients treated with LEMTRADA were relapse-free at two years, compared to 47 percent with Rebif (p<0.0001). In addition, in CARE-MS II, LEMTRADA reduced relapse rate to a greater extent than Rebif in all subgroups defined by previous therapy, including: with or without any interferon therapy, and those previously treated with Rebif or Copaxone ® (glatiramer acetate injection). Study data also showed a strong clinical benefit by reducing the risk of sustained accumulation of disability in patients taking LEMTRADA in CARE-MS ll by 42 percent as compared with Rebif (p=0.008), with significant improvement in disability scores that suggested a reversal of pre-existing disability in some patients. In the trial, the mean disability score for patients treated with LEMTRADA decreased over a two-year period, indicating an improvement in their physical disability, while the mean score for patients given Rebif increased, indicating a worsening of disability (p<0.0001).