AB Science S.A. reported that the Independent Data Safety Monitoring Committee (IDMC) recommended continuation of the phase 3 study evaluating masitinib in the treatment of primary progressive or relapse-free secondary progressive multiple sclerosis, with no Sample Size Reestimation (SSR) necessary. Study AB07002 is a double-blind, randomized, placebo-controlled phase 3 trial designed to assess the safety and efficacy of masitinib in patients with primary progressive or relapse-free secondary progressive multiple sclerosis. The treatment period is 96 weeks. The primary efficacy endpoint is the change over 96 weeks in EDSS (Expanded Disability Status Scale), which is a scale used for quantifying disability in multiple sclerosis and monitoring changes in the level of disability over time. The study recruitment was completed with 656 enrolled patients. In accordance with study protocol, an interim analysis was planned to be performed once 50% of the study population had reached the 96 weeks treatment duration period. IDMC used the conditional power (predictive probability of success) calculation based on the primary endpoint to give its recommendation regarding study continuation and SSR. Based on conditional power (CP) calculation using the current sample size, the IDMC recommended the continuation of the study with no reestimation of sample size meaning that according to the protocol, the predictive probability of success of the study is above 80% with the current sample size. Additionally, the IDMC did not report any safety concern with masitinib in the study population. The interim analysis was performed without any unblinding for the sponsor. Final results of the study are expected in second quarter of 2019. Four principal courses of MS are currently defined according to clinical characteristics; namely: Relapsing Remitting MS (RRMS), Secondary Progressive MS (SPMS), Primary Progressive MS (PPMS), and Progressive Relapsing MS (PRMS). The disease typically presents as RRMS, with more than 50% of RRMS patients entering a progressive phase (SPMS) following a highly variable delay. Approximately 10 to 15% of patients present with PPMS, which is characterized by continuous disease progression from the onset of disease, i.e. without relapses and remissions, for which prognosis is considered as poor due to the relatively rapid development of advanced disability as compared with RRMS.