Abstract
BACKGROUND: Peginterferon beta-1a was developed for treatment of relapsing-remitting multiple sclerosis (RRMS) to provide an interferon with increased exposure to facilitate adherence by reducing frequency of application. This non-interventional observational study investigated the adherence to peginterferon beta-1a in real-world clinical practice settings. METHODS: This prospective study was conducted from 1/2015 to 1/2018 at 77 German MS sites. Adult patients with RRMS (previously treated or treatment-naïve) receiving peginterferon beta-1a (125 µg SC every 2 weeks) were eligible for participation. Data were documented every 3 months over 2 years (nine visits). The primary endpoint was the percentage of patients with overall adherence defined as ⩽10% of injections not administered throughout the 24-month observation period. Secondary endpoints included persistence, patient satisfaction, efficacy (relapse activity, disability progression), and tolerability. Patients were invited to participate in an individualised patient support programme. RESULTS: Out of 250 enrolled patients, 190 (aged 18-74 years, 75.3% female) were included in the efficacy analysis. Of those, 74 patients completed the study; 33.2% were treatment-naïve. The proportion of patients with an overall adherence of >90% was 75.7% (95% CI 67.9-81.6). The annualised relapse rate was 0.17. Compared with previous therapies, the scores for treatment satisfaction and convenience were markedly higher with peginterferon beta-1a. Overall, 87.4% participated in the patient support programme, and 47.8% of patients reported adverse events. CONCLUSIONS: Adherence to the bi-weekly treatment with peginterferon beta-1a was very high. Although adherence could have been positively influenced by the well-accepted patient support programme, the extent could not be unequivocally evaluated. Clinical disease activity remained low. Peginterferon beta-1a was well tolerated, and there were no new relevant safety findings.