The Use of Delayed-Release Dimethyl Fumarate in Routine Medical Practice in the Treatment of Multiple Sclerosis (ESTEEM): 6-Month Interim Analysis

Background: ESTEEM is an ongoing, multinational, 5-year prospective study evaluating the long-term safety and efficacy of delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) in 5000 patients.

Objectives: To characterize the benefit-risk profile of DMF in patients with relapsing-remitting multiple sclerosis (RRMS) treated under routine clinical care in a long-term observational study.

Methods: Eligible patients are newly prescribed DMF for the treatment of RRMS under routine clinical care. Patients are recruited from approximately 300 sites located globally. Data will be captured for up to 5 years after enrollment. The primary objective is to determine the incidence, type, and pattern of serious adverse events (SAEs); secondary objectives include the assessment of prescription and utilization patterns, effectiveness of DMF on RRMS disease activity and disability progression, and the effect of DMF on health-related quality of life, healthcare resource consumption, and work productivity.

Results: As of July 22 2015, 1000 patients enrolled and accrued up to 6 months follow-up time. Of the initial 1000 patients, 897 patients qualified for the interim analysis; 680 (75.8%) were female. Mean and median age at enrollment was 42 years. An Expanded Disability Status Scale (EDSS) examination was conducted in 389 (48.2%) patients prior to enrollment (median time between last EDSS and enrollment was 1 year); median EDSS score was 2.00. The majority of patients (n=658; 73.4%) received prior RRMS treatments (intramuscular interferon β-1a, 35%; subcutaneous interferon β-1a, 31%; glatiramer acetate, 37%). A total of 19 (2.1%) patients reported an SAE, of which 6 patients reported an infection and 4 patients reported gastrointestinal disorders. Gastrointestinal disorders represented the most frequent AE leading to discontinuation of DMF treatment.

Conclusions: This interim analysis of ESTEEM indicates that the study population is similar to the broader RRMS population. To date, the number of patients with reported SAEs has been low and comparable with the known safety profile of DMF. Additional data may be presented.

Study supported by: Biogen