Brain Imaging and Immune Changes During Remibrutinib Treatment in Multiple Sclerosis.

REDEFINE-MS is a research study for people with relapsing multiple sclerosis (MS) who are participating in the RESHAPE-MS trial. The study aims to better understand how remibrutinib affects inflammation in the brain and spinal cord by using PET imaging, MRI scans, blood samples, and cerebrospinal fluid (CSF) samples collected before treatment and again six months later. [REDEFINE_p...2026_clean | Word] The main question the study is trying to answer is whether remibrutinib changes immune activity and inflammation in people with MS, and whether these changes can be measured using imaging and biological markers that may help predict future disease progression and treatment response.