To evaluate persistence and adherence in patients with multiple sclerosis (MS) treated with diroximel fumarate (DRF) in real-world clinical practice.

DRF is approved for relapsing forms of MS; it has the same pharmacologically active metabolite as dimethyl fumarate (DMF) and a similar efficacy and safety profile. Clinical studies of DRF demonstrated favorable gastrointestinal (GI) tolerability and a low rate of treatment discontinuation due to GI adverse events (AEs). Preliminary data suggest that MS patients treated with DRF have high rates of persistence and adherence in the real-world setting; however, those preliminary studies have included small patient numbers; evaluation of real-world DRF persistence in a larger patient population is needed.

This retrospective analysis of the AcariaHealth Specialty Pharmacy Program included patients who initiated DRF from 01-Dec-2019 through 30-Jan-2021 with data extraction on 30-Jun-2021. Endpoints included persistence (proportion of patients remaining on therapy), discontinuation rate due to GI AEs, and adherence measured by proportion of days covered (PDC). GI AEs included: (a) GI-related AEs that occurred at any time or (b) any unknown AE that occurred ≤90 days after DRF initiation. 

Overall, 1,143 patients were included; 433 (38%) patients had been treated with prior DMF. Median (range) DRF treatment duration was 7.1 (0.1-20.0) months. The overall estimated proportion of patients remaining on DRF treatment at 16 months was 82.3% (95% CI 77.2-86.3). Fifty-two (4.5%) patients discontinued DRF due to GI AEs.  Mean PDC was 90.8% (95% CI, 89.2–92.5) and 85.4% (95% CI: 83.3-87.4) of patients achieved a PDC ≥80%.

In this analysis of >1,000 patients treated with DRF in real-world clinical practice, overall persistence at 16 months was high, treatment discontinuation due to GI AEs was low, and patients were highly adherent to therapy. 

Study Supported by: Biogen