Real-World Characterization of Flu-like Symptom Severity and Duration in Patients with RMS: Interim Analysis of the Peginterferon Beta-1a Pop Study

Background: The PLEGRIDY^® Observational Program (POP) is an ongoing 5-year phase 4 study of the long-term real-world effectiveness and safety of peginterferon beta-1a.

Objectives: Evaluate real-world experience of flu-like symptoms (FLS) and correlations between FLS severity and duration in patients with relapsing multiple sclerosis (RMS) receiving peginterferon beta-1a.

Methods: This interim analysis included patients with ≥12 months of treatment in POP as of September 2016, classified as peginterferon beta-1a naïve (“PegNaïve”, started treatment ≤31 days pre-enrollment) or as peginterferon beta-1a experienced (“PegExp”, started treatment >31 days pre-enrollment). Patients reported FLS duration and severity and assessed FLS prophylaxis effectiveness and effectiveness satisfaction at baseline and every 3 months thereafter. Updated data as of October 2017 will be presented.

Results: A higher proportion of PegNaïve patients (n=278) compared to PegExp patients (n=189) experienced FLS (16% vs 3%). Of patients reporting FLS severity following their most recent peginterferon beta-1a injection, over 90% of both PegNaive and PegExp patients had mild/moderate symptoms over 12 months; the proportion of patients with severe symptoms generally declined from baseline (PegNaïve, 9.9%; PegExp, 6.2%) to 12 months (2.5%; 2.9%). Comparatively, fewer patients taking FLS-reducing medications reported severe symptoms from baseline (PegNaïve, 5.3%; PegExp, 3.6%) through 12 months (1.9%; 2.1%). Over 12 months, patient-reported FLS medication effectiveness and satisfaction with medication effectiveness was high (median score ≥8/10) in each group, and the proportions of both PegNaïve and PegExp patients reporting FLS duration as ≤24 and >24 hours were fairly consistent. Generally, more patients reported mild FLS experienced symptoms for ≤24 hours (vs >24 hours), whereas more patients who reported moderate/severe FLS experienced symptoms for >24 hours (vs ≤24 hours); these correlations were consistent over 12 months in both PegNaïve and PegExp subgroups.

Conclusions: PegNaïve patients were more likely than PegExp patients to have FLS. For patients in both subgroups who experienced FLS, symptoms tended to be mild or moderate, decreased over time, and were well-managed by FLS medication. Symptom severity tended to correlate positively with duration. The long-term results of this real-world study may help optimize FLS management in patients treated with peginterferon beta-1a, particularly in those initiating treatment.

Support: Biogen