Study description: The TYSABRI Observational Program (TOP) is a 15-year, multinational (ex-US), prospective study observing 6321 patients with relapsing-remitting multiple sclerosis (RRMS) initiating TYSABRI in real-world clinical practice settings. The study assesses the long-term safety of natalizumab treatment. Secondary endpoints evaluate MS disease activity including ARR.1-3
Study limitations2:
The TOP study was funded by Biogen.