Real-world propensity score comparison of treatment effectiveness of peginterferon beta-1a vs. subcutaneous interferon beta-1a, glatiramer acetate, and teriflunomide in patients with relapsing-remitting multiple sclerosis

Abstract

Background: Multiple disease-modifying therapies (DMTs) have been approved by the U.S. Food & Drug Administration for the treatment of relapsing-remitting multiple sclerosis (RRMS). In separately conducted clinical trials, peginterferon beta-1a, subcutaneous interferon beta-1a (SC IFN beta-1a), glatiramer acetate (GA), and teriflunomide have demonstrated efficacy for reducing relapses. No head-to-head phase III clinical trials have directly compared the treatment efficacy of peginterferon beta-1a with these other DMTs.

Objectives: A propensity score-based comparison was conducted of the treatment effectiveness of peginterferon beta-1a vs. SC IFN beta-1a, GA, and teriflunomide among patients with RRMS identified from a large U.S. administrative healthcare claims database.

Methods: Adult patients (18-65 years of age) who had ≥1 claim for an MS diagnosis between November 2013 and June 2017 and ≥1 claim for peginterferon beta-1a, SC IFN beta-1a, GA, or teriflunomide between November 1, 2014, and March 31, 2017 were identified from the IBM® MarketScan® Commercial database. The index date was the first claim of a patient's DMT initiated. Only patients who had ≥12 months of insurance enrollment pre-index (baseline period) and ≥90 days post-index (variable length follow-up period) were included. Patients were grouped into cohorts according to the index DMT. Patient demographics and clinical characteristics were evaluated. Propensity score matching (PSM) was separately conducted for pairwise comparisons of treatment effectiveness between peginterferon beta-1a and the other DMT cohorts. During the post-index follow-up period, annualized relapse rate (ARR; relapse defined as hospitalization or outpatient visit with subsequent treatment), annualized number and length of inpatient stays, and the number of claims for durable medical equipment were evaluated.

Results: With PSM, there were 325 patients (mean age: 46.0 years) in the peginterferon beta-1a cohort compared to 967 (mean age: 46.9 years) in the SC IFN beta-1a cohort; likewise there were 564 patients (mean age: 47.4 years) in the peginterferon beta-1a and 1688 (mean age: 47.6 years) in the GA cohort; and finally there were 584 patients (mean age: 49.1 years) in the peginterferon beta-1a cohort and 1742 (mean age: 49.0 years) in the teriflunomide cohort. During the post-index follow-up period, the ARR did not significantly differ between the peginterferon beta-1a and SC IFN beta-1a cohorts; the ARR was lower among patients treated with peginterferon beta-1a than among those treated with GA (Least squares mean [LSM] estimate: 0.25 vs. 0.31; LSM ratio: 0.809; P=0.027) or teriflunomide (LSM estimate: 0.26 vs. 0.37; LSM ratio: 0.704; P<0.001). The annualized mean number and length of inpatient stays and the mean number of claims for durable medical equipment during the post-index follow-up did not differ between the matched peginterferon beta-1a and GA cohorts nor the peginterferon beta-1a and teriflunomide cohorts.

Conclusion: In this real-world comparative analysis of patients with similar patient characteristics, treatment with peginterferon beta-1a was associated with lower ARRs than treatment with either GA or teriflunomide; ARRs did not differ among patients treated with SC IFN beta-1a. Also, all other measured secondary outcomes did not differ between study cohorts. These real-world data may help support decision-making in the treatment of patients with RRMS.

Keywords: Annualized relapse rate; Comparative treatment effectiveness; Glatiramer acetate; Peginterferon beta-1a; Propensity score comparison; Relapsing-remitting multiple sclerosis; Subcutaneous interferon beta-1a; Teriflunomide.