Subcutaneous Interferon Beta Therapy in Multiple Sclerosis Patients – Characterization of Injection Site Reactions and Flu-Like Symptoms in a Daily Practice Setting – Results from the Non-Interventional Study PERFECT

PURPOSE: The purpose of this study was to assess the prevalence of injection site reactions (ISR) and flu-like symptoms (FLS) during treatment with subcutaneous (SC) interferon (IFN) beta therapies and to document measures to mitigate and prevent ISR and FLS. PATIENTS AND METHODS: The cross-sectional post-authorization safety study PERFECT was conducted from 11/2017 to 7/2019 in neurology practices in Germany. Adult patients with relapsing-remitting multiple sclerosis (MS) receiving SC IFN beta for ≥3 months were eligible. The primary endpoints were patient-reported prevalence of ISR and FLS. Additional endpoints reported by patients, MS nurses, and neurologists included type, frequency, duration, time of occurrence, and management of ISR and FLS. RESULTS: In total, 603 patients (median age 45 years [range 36–53], 74% female) were included in the analysis. Time since MS diagnosis was >5 years in most patients. The majority had received none (64%) or 1 (22%) prior therapy. Current MS therapy in 36%, 32%, and 30% of patients was IFN beta-1b, IFN beta-1a, and peginterferon beta-1a, respectively. ISR and FLS under current therapy were reported by 84% and 68% of patients, respectively. ISR developed within 5 days after injection (84%) and lasted for 2–14 days (53%) in most patients. The most frequent patient-reported symptom was erythema (39%). ISR resolved or abated with systemic treatments or topical ointments. Most frequent preventive measures included alternating injection sites (58%). Occurrence of ISR rarely resulted in treatment interruption (5%). FLS occurred predominantly up to 6 h after injection (40%) and lasted <12 h (26%). The most frequent patient-reported symptoms were fatigue (15%) and aching limbs (15%). Assessments by physicians and MS nurses differed from patient-reported results. CONCLUSION: Although ISR were experienced by the majority of patients, they rarely resulted in treatment interruption. In this real-world setting, ISR and FLS management was in line with published expert recommendations.