The expected duration of the treatment in this study is approximately 8 months, based on a maximum 28-day screening period, followed by a 6-month (6-cycle) treatment period, and an EOT visit for subjects who will not continue the treatment after completing the 6 cycles of SAR302503, or discontinue the treatment early for any reasons as well as a follow-up visit which should occur 30 days after the last administration of SAR302503. Patients who continue to benefit clinically will be allowed to remain on study medication beyond the 6-month treatment period until the occurrence of disease progression or unacceptable toxicity.