VANCOUVER, BC—Results of the 6-month interim analysis of RESPOND suggests that dimethyl fumarate (DMF) is associated with lower annualized relapse rates (ARR) and improvement on patient reported outcomes (PROs) in patients with relapsing multiple sclerosis (RMS) who switch to DMF following suboptimal response to glatiramer acetate (GA), researchers presented at the 68th AAN Annual Meeting.

Noting limited information is available on clinical and patient-reported outcomes in relapsing-remitting multiple sclerosis (MS) among those who switch from glatiramer acetate to dimethyl fumarate after suboptimal response in the real-world setting, Kiren Kresa-Reahl, MD, of Providence Multiple Sclerosis Center, Portland, OR, and colleagues are conducting RESPOND, a Phase 4, prospective, multicenter, 12-month open-label observational study.

Eligibility criteria included ongoing treatment with and suboptimal response (eg, suboptimal efficacy, intolerance, or poor adherence) to glatiramer acetate or discontinuation of glatiramer acetate as a result of suboptimal response within 30 days of enrollment and a pre-enrollment decision to initiate DMF. DMF treatment was initiated within 60 days after enrollment. 

The investigators collected relapse data from medical records to assess clinical effectiveness of DMF. “ARR at 6 months of DMF treatment was lower than the ARR at 12 months before treatment initiation,” Dr. Kresa-Reahl noted.

Prior to initiation and at Months 6 and 12 after treatment with DMF, patients completed the 14-item Treatment Satisfaction Questionnaire for Medication (TSQM-14), the Short Form-36 (SF-36), the Modified Fatigue Impact Scale (MFIS-5), the Beck Depression Inventory (BDI-7), the Work Productivity and Impairment Questionnaire: Multiple Sclerosis (WPAI-MS), the Morisky 8-item Medication Adherence Scale (MMAS-8), and the patient-reported Expanded Disability Status Scale (EDSS).

The majority of patients (95%) had no relapses after 6 months of treatment with DMF. In addition, statistically significant improvements from baseline at 6 months were observed for SF-36 PCS and MCS, TSQM-14, BDI-7, and MFIS-5 scores. Specifically, PCS and MCS scores improved significantly (P=0.0118 and P=0.0003, respectively). Patient treatment satisfaction level also increased significantly as demonstrated by higher TSQM-14 scores; MFIS-5 and BDI-7 scores also reflected significant improvements in fatigue and depression symptoms.

As of June 12, 2015, RESPOND had enrolled 333 patients of which 318 received ≥1 dose of DMF; mean age was 47.6 years, 82.7% were female, and 91.2% were white. Patient reasons for discontinuation (more than one could be selected) of the most recent glatiramer acetate treatment included efficacy (50.6%), tolerability (45.3%), or safety (4.7%); lack of adherence (5%); and patient preference (37.4%). A total of 168 completed the study with 68 discontinuations and 20 that withdrew for reasons including adverse events, efficacy, lost to follow-up, investigator decision, and death (1 case reported unrelated to DMF treatment).

The study authors noted that data collection is anticipated to be completed in 2016. The final analysis will contain data on individual components of the SF-36 PCS and MCS, WPAI-MS, MMAS-8, and PREDSS.