sentences:  The study intends to enroll over 200 patients with relapsing MS who have failed earlier treatment with an interferon-beta and will compare two doses of the drug to placebo over a period of six months.The results are expected by the end of 2008., Preliminary interim efficacy analysis showed that patients enrolled in this clinical trial did not benefit as expected from zaurategrast compared to placebo after a six-month treatment period.No cases of progressive multifocal leukoencephalopathy were noted.