Persistence, Adherence, and Quality of Life in Patients Treated with an Intramuscular Interferon Beta-1a Autoinjector in a Real-World Clinical Setting

Background: The intramuscular interferon beta-1a (IM IFNβ-1a) autoinjector (AVONEX PEN^®) was approved for the treatment of multiple sclerosis (MS) in Europe in 2011 and in the United States in 2012.

Objectives: To describe the results of the PERSIST study, which prospectively evaluated once-weekly use of the IM IFNβ-1a autoinjector over 12 months in patients with MS in a real-world clinical setting.

Methods: PERSIST was a global, prospective, observational, 12-month, open-label, phase 4 study of MS patients self-administering IM IFNβ-1a therapy by autoinjector. Outcomes evaluated included physician-reported persistence and patient-reported compliance, tolerability, quality of life, ease of use, and satisfaction. Preliminary 12-month data for the preplanned analysis are reported.

Results: Of the 274 MS patients (mean age 43.0 years; 75.8% female) enrolled, 219 were included in the intent-to-treat population and 158 patients have completed the 12-month visit and contribute to the interim dataset. Among completers, 92.4% of patients (146/158) persisted in using the autoinjector through month 12; contributers to nonpersistence included adverse events, disease progression, and loss to follow-up. Based on all available data over 12 months, overall compliance (not missing any injections) was 75.4% (150/199) and the proportion of patients missing <20% of injections was 97.0% (193/199). From baseline to 12 months, the proportion of patients requiring injection assistance from a caregiver decreased from 10.0% to 5.2%. Similarly, fear of injection was reduced from 17.5% (baseline) to 2.4% (month 12). Among patients who completed their injection-related questionnaires, 75.4% (92/122) reported injection-site pain levels ≤2 (0=no pain; 10=extremely painful) and 74.4% (93/125) reported no injection-site reactions at month 12. At month 12, almost all patients (96.0% [119/124]) reported being satisfied or very satisfied with the autoinjector. Final 12-month results will be presented.

Conclusions: In this real-world setting, patients reported that the IM IFNβ-1a autoinjector was well tolerated, easy to use, and associated with high levels of compliance, reduced need for injection assistance, and reduced fear of injection; physician-reported persistence was also high. Potential study limitations related to patient-reported outcomes will be further explored in the final results.