Achievement of No Evidence of Disease Activity-3 with Oral Disease-Modifying Treatment in Patients with Relapsing-Remitting Multiple Sclerosis

Background: There is scant data regarding the use of oral disease-modifying treatments (oDMT) in patients with relapsing-remitting multiple sclerosis (PwRRMS) from Saudi Arabia. Objective: This study aimed to identify the response rate to oDMT in PwRRMS compared to interferon (IFN) in terms of achieving no evidence of disease activity-3 (NEDA-3). Methods: This retrospective study was conducted at a tertiary care hospital in Saudi Arabia and included all adult PwRRMS over a 2-year period who were on oDMTs or IFN for <1 year. The achievement of overall NEDA-3 and its components (namely, relapse, disability progression, and focal MRI activity) were assessed for each treatment. Results: A total of 231 patients were included for the analysis of NEDA-3 status, of which 78 (33.8%) were on oDMTs (namely, dimethyl fumarate, teriflunomide, and fingolimod). NEDA-3 status was achieved in 51.3% (OR: 1.86, 95% CI: 1.28-2.71) of patients on oDMTs and in 32% of patients on IFN (OR: 0.72, 95% CI: 0.58-0.89) (P < 0.001). Compared to the IFN group, the oDMT group had significantly lower rates of clinical relapse (P < 0.001), disability progression (P = 0.004), and new focal MRI activity (P = 0.01). Patients on dimethyl-fumarate had higher odds of achieving NEDA-3 (OR: 2.18, 95% CI = 1.09-4.34; P =0.02) compared with those on fingolimod (OR 2.15, 95% CI = 0.70-6.58; P =0.16) and teriflunomide (OR: 1.53, 95% CI = 0.81-2.91; P =0.18). Conclusion: More than half of the patients with relapsing-remitting multiple sclerosis on oral DMTs achieved NEDA-3 status in this study. Significant differences were observed in NEDA-3 status parameters and achievement between patients on oral DMTs and interferon, with the likeliness being highest among patients treated with dimethyl-fumarate.