The effectiveness of natalizumab vs fingolimod-A comparison of international registry studies. - Andersen JB; Sharmin S; Lefort M; Koch-Henriksen N; Sellebjerg F; Sørensen PS; Hilt Christensen CC; Rasmussen PV; Jensen MB; Frederiksen JL; Bramow S; Mathiesen HK; et al. (Multiple sclerosis and related disorders, 2021)