Background: PRO-MSactive is a French phase-IV study evaluating ocrelizumab efficacy in active relapsing-remitting or secondary progressive multiple sclerosis (RRMS or SPMS). By linking clinical data to the national claims database (SNDS), the objective of this study was to obtain an overview of RRMS and SPMS burden.

Methods: All RRMS and SPMS patients included in the PRO-MSactive study between July 2018 and July 2019 and followed for 48 weeks were linked to MS patients from SNDS. Healthcare Resource Utilization and costs were described in RRMS patients, in the two years prior to ocrelizumab initiation, by 12 months period (n-1 and n-2), according to EDSS score (< 4 versus ≥4).

Results: 291/371 patients (78.7 %) were included: 257 RRMS and 34 SPMS patients. Different costs according to disability status (year n-2: 9,103€ versus 16,441€; year n-1: 9,813€ versus 19,999€, for patients with score EDSS <4 versus ≥4, respectively) and relapse activity (+1,358€ between year n-2 and n-1) were observed.

Conclusions: This study is the first to combine clinical data from a phase-IV study with a claims database allowing to distinguish costs according to disease type. We objectified a greater economic burden in RRMS patients with higher levels of disability and showed an increase in costs associated with relapse activity in the 2 years before enrolling in the phase IV study.