Long‐Term Safety of Teriflunomide in Multiple Sclerosis Patients: Results of Prospective Comparative Studies in Three European Countries

Background and Objectives: Teriflunomide is a disease-modifying therapy (DMT) for multiple sclerosis (MS). This post authorisation safety study assessed risks of adverse events of special interest (AESI) associated with teriflunomide use. Methods: Secondary use of individual data from the Danish MS Registry (DMSR), the French National Health Data System (SNDS), the Belgian national database of health care claims (AIM-IMA) and the Belgian Treatments in MS Registry (Beltrims). We included patients treated with a DMT at the date of teriflunomide reimbursement or initiating another DMT. Adjusted hazard rates (aHR) and 95% confidence intervals were derived from Cox models with time-dependent exposure comparing teriflunomide treatment with another DMT. Results: Of 81 620 patients (72% women) included in the cohort, 22 324 (27%) were treated with teriflunomide. After a median follow-up of 4 years, teriflunomide use compared to other DMT was not associated with a risk of all-cause mortality, severe infection, pneumoniae, herpes zoster reactivation, pancreatitis, cardiovascular condition and cancers. For opportunistic infections, aHR for teriflunomide versus other DMT was 2.4 (1.2–4.8) in SNDS, which was not bound to a particular opportunistic agent. The aHR was 2.0 (1.1–3.7) for renal failures in the SNDS, but no association was found in other data sources. A total of 187 SNDS patients had a history of renal failure prior to cohort entry. None of these patients (0%) had a renal failure recurrence when treated with teriflunomide for 19 (13%) recurrences reported for patients on another DMT. Discussion: We found no evidence that teriflunomide use would be associated with an increased risk of AESI. Trial Registration EUPAS register: EU PAS 19610.