Roche’s investigational drug, Fenebrutinib has shown brain penetration and significant reduction in lesions in patients with relapsing multiple sclerosis (MS) from the recent release of new data from Phase II FENopta study. Fenebrutinib is a potent and highly selective Bruton’s tyrosine kinase (BTK) inhibitor, and currently the only reversible inhibitor being tested in Phase III MS trials. BTK inhibitor is involved in key pathological features of MS, including B-cell development and activation.