DMF is a well-established therapy for relapsing forms of multiple sclerosis (RMS); data from ENDORSE, an extension to phase 3 studies DEFINE and CONFIRM, has enabled >10 years follow-up.
We report safety/efficacy of DMF in patients with RMS treated with DMF and followed for 13 years in ENDORSE (NCT00835770) (2 years DEFINE/CONFIRM, and >10 years ENDORSE).
Incidence of serious AEs (SAEs), discontinuations due to AEs, annualized relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score were assessed. Patients were treated with DMF 240 mg BID: placebo (PBO)/DMF (PBO, years 0–2 /DMF, years 3–10) or continuously (DMF/DMF). Efficacy outcomes were assessed in patients up to 10 years due to sample size considerations. For lymphocyte analysis, data from first DMF exposure were analysed for patients in DEFINE/CONFIRM/ENDORSE.
At 23 January 2020, 1736 patients enrolled/received ≥1 dose DMF. Of 1736 patients, 760 completed. Patients were followed for a median (min,max) of 6.76(0.04,10.98) years in ENDORSE, and 2 years in DEFINE/CONFIRM. Overall, 551 (32%) patients experienced SAEs; most were MS relapse and fall. There was one case of PML in this study. There was no increased incidence of other infections or serious infections. Sixteen percent (n=282) patients discontinued due to AEs; 2% relapse, 2% disease progression, and 4% GI disorders. ALC decreased over the first 48 weeks, and then remained generally stable for the majority of the study. The proportion of patients with other AEs of special interest (including opportunistic infection, malignancy, and serious herpes zoster) was similar regardless of ALC. For patients continuously treated (n=501), overall ARR remained low (0.141[95% CI, 0.119,0.167]), while for PBO/DMF patients (n=249) ARR decreased after initiating DMF (ARR 0–2 years, 0.330[95% CI, 0.266,0.408]; ARR overall, 0.149[95% CI, 0.116,0.190]). Overall, 60% of DMF/DMF and 66% of PBO/DMF patients remained relapse-free; 20% and 17% of patients had 1 relapse, respectively. Walking abilities were maintained throughout the study; the number of patients with EDSS scores ≤3.5 was 413/479(86%) DMF/DMF (179/217[82%] PBO/DMF) at Year 2, and 173/226(77%) DMF/DMF (67/90[74%] PBO/DMF) at Year 10. Seventy-two percent and 73% of DMF/DMF and PBO/DMF patients, respectively, had no 24-week confirmed disability progression over 10 years.
These safety and efficacy data in patients followed for 13 years, support DMF as a long-term option for patients with RMS.