Abstract
No systematic review of trial designs in patients with relapsing multiple sclerosis (RMS) was reported. This systematic review was conducted on the trial designs and primary end points (PEs) of phase II and III trials intended to modify the natural course of the disease in patients with RMS. The purpose of the study is to explore trends/topics and discussion points in clinical trial design and PE, comparing them to regulatory guidelines and expert recommendations. Three trial registration systems, ClinicalTrials.gov, the EU Clinical Trials Register, and the Japan Registry of Clinical Trials, were used and 60 trials were evaluated. The dominant clinical trial design was a randomized controlled parallel-arms trial and other details were as follows: in adult phase III confirmatory trials (n = 32), active-controlled double-blind trial (DBT) (53%) and active-controlled open-label assessor-masking trial (16%); in adult phase II dose-finding trials (n = 9), placebo- and active-controlled DBT (44%), placebo-controlled DBT (22%), and placebo-controlled add-on DBT (22%); and in pediatric phase III confirmatory trials (n = 8), active-controlled DBT (38%) and active-controlled open-label non-masking trial (25%). The most common PEs were as follows: in adult confirmatory trials, annual relapse rate (ARR) (56%) and no evidence of disease activity-3 (NEDA-3) (13%); in adult dose-finding trials, the cumulative number of T1 gadolinium-enhancing lesions (56%), combined unique active lesions (22%), and overall disability response score (22%); and in pediatric confirmatory trials, ARR (38%) and time to first relapse (25%). It was suggested that some parts of the regulatory guidelines and expert recommendations need to be revised.