Efficacy and Safety of Delayed-release Dimethyl Fumarate for Relapsing-remitting Multiple Sclerosis in Prior Interferon Users: An Integrated Analysis of DEFINE and CONFIRM.

PURPOSE

In Phase III studies (DEFINE [Determination of the Efficacy and Safety of Oral Fumarate in Relapsing-Remitting MS]/CONFIRM [Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis]), delayed-release dimethyl fumarate (DMF) demonstrated significant efficacy and a favorable benefit-risk profile in patients with relapsing-remitting multiple sclerosis (RRMS). Post hoc analyses of integrated data from DEFINE/CONFIRM were conducted to evaluate the effect of DMF in patients previously treated with interferon (IFN) beta.

METHODS

Patients (age 18-55 years; Expanded Disability Status Scale score, 0-5.0) were randomized to receive DMF 240 mg BID or TID, placebo, or glatiramer acetate (CONFIRM only) for up to 2 years. Previous IFN users received at least 1 IFN treatment >3 months before randomization. Data for DMF 240 mg BID (approved dosing regimen) are reported.

FINDINGS

In the integrated intention-to-treat population, 172 and 169 patients receiving DMF or placebo, respectively, had received ≥1 prior IFN. In this subgroup, significant reductions with DMF versus placebo were observed for the annualized relapse rate (rate ratio, 0.55 [95% CI, 0.40-0.77]), new/newly enlarging T2-hyperintense lesions (lesion mean ratio, 0.16 [95% CI, 0.09-0.29]), odds of having more gadolinium-enhancing lesions (odds ratio, 0.17 [95% CI, 0.07-0.44]), and new T1-hypointense lesions (lesion mean ratio, 0.25 [95% CI, 0.14-0.45]). Median Expanded Disability Status Scale scores remained stable during the study period. Adverse events associated with DMF included flushing and gastrointestinal events.

IMPLICATIONS

In this post hoc analysis in patients with previous IFN treatment, DMF demonstrated significant efficacy over 2 years versus placebo and an adverse event profile consistent with the overall population of DEFINE/CONFIRM. ClinicalTrials.gov identifiers: DEFINE, NCT00420212; and CONFIRM, NCT00451451.