Safety and clinical effectiveness of peginterferon beta-1a for relapsing multiple sclerosis in the real-world setting: Interim results from the Plegridy Observational Program

Safety and clinical effectiveness of peginterferon beta-1a for relapsing multiple sclerosis in a real-world setting: Final results from the Plegridy Observational Program

Background

Interferon beta-1a remains an important treatment option for multiple sclerosis, particularly when safety or tolerability concerns may outweigh the benefits of higher-efficacy disease-modifying therapies. The five-year phase 4 Plegridy Observational Program (POP) study (NCT02230969) collected data on real-world safety and effectiveness of Plegridy® (peginterferon beta-1a) treatment in patients with relapsing multiple sclerosis.

Objective

To explore the real-world safety and effectiveness of peginterferon beta-1a in patients with relapsing multiple sclerosis, including factors influencing treatment discontinuation.

Methods

Data were collected prospectively from patients ≥ 18 years old with relapsing multiple sclerosis for overall population analysis and for subpopulations including newly/previously diagnosed patients, age, and experience with peginterferon beta-1a. Outcome measures included annualized relapse rates, adverse events, and predictors of time to treatment discontinuation.

Results

Mean (SD) treatment duration in the overall population (N = 1172) was 896.0 (733.15) days. Incidence of adverse events was higher in new than experienced users (79.4% vs. 57.0%). New users were more likely than experienced users to discontinue (hazard ratio = 1.60; P < 0.0001). The adjusted annualized relapse rate was 0.09, and at the end of 5 years, 77.1% of patients were relapse-free.

Conclusions

Peginterferon beta-1a is an effective therapy for managing relapsing multiple sclerosis. The identification of predictors of discontinuation can help inform strategies to enhance treatment persistence.

Prolonged Interferon-Stimulated Gene and Protein Signatures in Multiple Sclerosis Induced by PEGylated IFN-β-1a Compared to Non-PEGylated IFN-β-1a

Interferon (IFN)-β-1a (Avonex) and longer half-life, polyethylene glycol-conjugated IFN-β-1a (PEG-IFN-β-1a, Plegridy), may generate different molecular responses. We identified different short-term and long-term in vivo global RNA signatures of IFN-stimulated genes in multiple sclerosis (MS) peripheral blood mononuclear cells and in selected paired serum immune proteins. At 6 h, non-PEGylated IFN-β-1a injection upregulated expression of 136 genes and PEG-IFN-β-1a upregulated 85. At 24 h, induction was maximal; IFN-β-1a upregulated 476 genes and PEG-IFN-β-1a now upregulated 598. Long-term PEG-IFN-β-1a therapy increased expression of antiviral and immune-regulatory genes (IFIH1, TLR8, IRF5, TNFSF10 [TRAIL], STAT3, JAK2, IL15, and RB1) and IFN signaling pathways (IFNB1, IFNA2, IFNG, IRF7), but downregulated expression of inflammatory genes (TNF, IL1B, and SMAD7). Long-term PEG-IFN-β-1a induced longer and stronger expression of Th1, Th2, Th17, chemokine, and antiviral proteins than long-term IFN-β-1a. Long-term therapy also primed the immune system, evoking higher gene and protein induction after IFN reinjection at 7 months than at 1 month of PEG-IFN-β-1a treatment. Both forms of IFN-β balanced correlations of expression among these genes and proteins, with positive correlations between Th1 and Th2 families, quelling the "cytokine storm" of untreated MS. Both IFNs induced long-term, potentially beneficial, molecular effects on immune and possibly neuroprotective pathways in MS.

Pharmacokinetics/pharmacodynamics by race: Analysis of a peginterferon β-1a phase 1 study

BACKGROUND

Black/African American participants are underrepresented in clinical trials for multiple sclerosis but can experience a greater burden of disease than other racial groups in the United States. A phase 1, open-label, crossover study that demonstrated bioequivalence of subcutaneous and intramuscular injection of peginterferon β-1a in healthy volunteers enrolled similar proportions of Black and White participants, enabling a post hoc subgroup analysis comparing these groups.

METHODS

Peginterferon β-1a (125 μg) was administered by subcutaneous or intramuscular injection, followed by a washout period before a second injection using the alternative method. The primary pharmacokinetic and pharmacodynamic endpoints were maximum observed concentration (C_max) and area under the concentration-time curve from hour 0 to infinity (AUC_inf) of study drug and serum concentration of neop-terin, respectively. Safety and tolerability were included as secondary endpoints.

FINDINGS

This analysis included 70 (51.5%) Black and 59 (43.3%) White participants. Peginterferon β-1a C_max was 29.8% higher in Black than in White participants following subcutaneous administration but was similar following intramuscular administration. Mean AUC_inf was 31.0% and 11.8% greater in Black than in White participants with subcutaneous and intramuscular administration, respectively. Pharmacodynamics and safety signals were similar between groups, although Black participants reported numerically fewer adverse events.

CONCLUSIONS

No clinically meaningful differences were identified between Black and White participants related to peginterferon β-1a administration, supporting the approved dose of 125 μg/mL peginterferon β-1a. Future clinical studies should include sufficiently diverse populations to ensure accurate assessments of treatment response.

FUNDING

Funding for medical writing support was provided by Biogen (Cambridge, MA, USA).