Efficacy and safety of peginterferon beta-1a compared to interferon beta-1a in relapsing remitting multiple sclerosis patients: A phase 3, randomized, non-inferiority clinical trial (PEGINTEGRITY)

Background: Multiple sclerosis (MS) is a prevalent, disabling, inflammatory, neurodegenerative disease that typically manifests during a highly productive stage of life. Interferon beta-1a was among the first approved disease-modifying therapies for MS and remains among the first-line treatment options. Pegylation of the interferon beta-1a molecule prolongs its half-life while maintaining its efficacy and safety profile. In PEGINTEGRITY study, we aimed to compare peginterferon beta-1a with interferon beta-1a in terms of efficacy and safety in relapsing-remitting multiple sclerosis (RRMS) patients. Methods: This study was a randomized, active-controlled, parallel-group, multi-center Phase 3 trial conducted in Iran in participants with RRMS. Participants received 125 mu g of subcutaneous peginterferon beta-1a every two weeks or 30 mu g of intramuscular interferon beta-1a once a week for up to 96 weeks. The primary outcome was the non-inferiority of peginterferon beta-1a to interferon beta-1a in reducing annualized relapse rate (ARR). Other outcomes included the number of patients with 12-week confirmed disability progression, the number of new or newly-enlarging T2 hyperintense lesions, the number of gadolinium-enhancing lesions, the number of new T1 hypointense lesions, the volume of new or newly-enlarging T2 hyperintense lesions, changes in brain volume, immunogenicity, and safety assessments. Results: A total of 168 patients who met the eligibility criteria were enrolled and assigned to two arms of the study, each consisting of 84 participants. Totally, 41 participants (24 patients in the peginterferon beta-1a group and 17 patients in the interferon beta-1a group) were withdrawn from the study. The withdrawn patients were included in the per-protocol analysis for the period of time they were in the study. In 96 weeks, in the perprotocol population, the ARR was 0.05 in the peginterferon beta-1a group versus 0.11 in the interferon beta1a group, which does not reflect a statistically significant difference (p=0.09; 95 % CI, 0.18-1.14). Considering the upper limit of the one-sided 95 % CI of the rate ratio of peginterferon beta-1a compared to interferon beta-1a, as well as the non-inferiority margin, it can be concluded that the primary outcome was met. The results were also comparable for other efficacy and safety outcomes. Conclusion: The results demonstrate the non-inferiority of peginterferon beta-1a to interferon beta-1a with similar efficacy in 96-week ARR in RRMS patients. Both arms were also comparable in other efficacy outcomes and safety profiles with no statistically significant differences. These findings support considering peginterferon beta1a as a safe and efficient option in patients with RRMS. This study was registered on Iranian Registry of Clinical Trials (IRCT201612306135N8) and clinicaltrials.gov (NCT05242133).