Review of Phase III Clinical Trials Outcomes in Patients with Secondary Progressive Multiple Sclerosis

Few satisfyingly effective treatments exist for patients with Secondary Progressive Multiple Sclerosis (SPMS). Our goal in conducting this review is to highlight clinical outcomes and study design, which may be applied to future phase III clinical trials for patients with SPMS.

A review of the available literature of phase III clinical trials since 1990 that specifically studied patients with SPMS. PubMed and ClinicalTrials.org were searched using appropriate terms.

Expanded Disability Status Scale (EDSS) was most often used as an outcome measure, with time to confirmed disability progression at three months being used most often. Components of the Multiple Sclerosis Functional Composite (MSFC) were the next most frequent primary outcome measure used. Patient Reported Outcomes (PROs) were frequently used as secondary outcome measures with specific PROs more successful than others. MRI measures related to brain parenchymal volume have recently started to be used in phase III clinical trials.

Some successful trials may have been related to patient selection for less inflammatory disease, which confounds the comparison between successful trials. Time to confirmed disability at three months or changes in composite MSFC are reasonable primary outcome measures to use in future SPMS trials with a suggestion that the MSFC may be more sensitive to progressive disease changes. PROs and MRI measures following brain parenchymal volume are reasonable secondary outcome measures to incorporate into future phase III trials in SPMS.