The prevalence of injection-site reactions with disease-modifying therapies and their effect on adherence in patients with multiple sclerosis: an observational study

Abstract

BackgroundInterferon beta (IFNβ) and glatiramer acetate (GA) are administered by subcutaneous (SC) or intramuscular (IM) injection. Patients with multiple sclerosis (MS) often report injection-site reactions (ISRs) as a reason for noncompliance or switching therapies. The aim of this study was to compare the proportion of patients on different formulations of IFNβ or GA who experienced ISRs and who switched or discontinued therapy because of ISRs.MethodsThe Swiss MS Skin Project was an observational multicenter study. Patients with MS or clinically isolated syndrome who were on the same therapy for at least 2 years were enrolled. A skin examination was conducted at the first study visit and 1 year later.ResultsThe 412 patients enrolled were on 1 of 4 disease-modifying therapies for at least 2 years: IM IFNβ-1a (n = 82), SC IFNβ-1b (n = 123), SC IFNβ-1a (n = 184), or SC GA (n = 23). At first evaluation, ISRs were reported by fewer patients on IM IFNβ-1a (13.4%) than on SC IFNβ-1b (57.7%; P < 0.0001), SC IFNβ-1a (67.9%; P < 0.0001), or SC GA (30.4%; P = not significant [NS]). No patient on IM IFNβ-1a missed a dose in the previous 4 weeks because of ISRs, compared with 5.7% of patients on SC IFNβ-1b (P = 0.044), 7.1% of patients on SC IFNβ-1a (P = 0.011), and 4.3% of patients on SC GA (P = NS). Primary reasons for discontinuing or switching therapy were ISRs or lack of efficacy. Similar patterns were observed at 1 year.ConclusionsPatients on IM IFNβ-1a had fewer ISRs and were less likely to switch therapies than patients on other therapies. This study may have implications in selecting initial therapy or, for patients considering switching or discontinuing therapy because of ISRs, selecting an alternative option.

Management Strategies for Flu-Like Symptoms and Injection-Site Reactions Associated with Peginterferon Beta-1a

“…Both FLSs and ISRs are common adverse events with interferon beta treatments for MS, adherence and treatment discontinuation also are reported to be associated with ISRs. [5][6][7] In this study, responders reported erythema to be the most common ISR associated with peginterferon beta-1a therapy. The reported incidence, onset, and duration of ISRs varied, and no consensus was obtained on the characteristics of ISRs in patients treated with peginterferon beta-1a.…”

“…5,6,9,16 Typically, FLSs occur within 6 hours after injection, dissipate within 24 hours, and are most prevalent during the first 6 months of treatment. 10,17,18 Consistent with this and based on the experiences in the ADVANCE study, the frequency and duration of FLSs generally declined after 3 months of treatment in a typical patient treated with peginterferon beta-1a.…”

“…1,2 Reasons for poor patient adherence to prescribed MS therapies include frequency of administration and adverse events, such as flu-like symptoms (FLSs) and injection-site reactions (ISRs), associated with interferon beta treatments. [3][4][5][6][7][8] Peginterferon beta-1a is a pegylated form of interferon beta-1a approved for the treatment of relapsing forms of MS. The safety and efficacy of peginterferon beta-1a 125 μg administered subcutaneously every 2 or 4 weeks …”

Postmarketing Safety Profile of Subcutaneous Interferon Beta-1a Given 3 Times Weekly: A Retrospective Administrative Claims Analysis

“…7 While numerous postmarketing, noninterventional observational studies involving IFN β-1a SC tiw have been conducted, most have focused on drug effectiveness or adherence as opposed to safety. [8][9][10][11][12][13] Others have focused on only 1 AE, 14,15 have had small sample sizes, or have featured relatively short follow-up periods (< 2 years). [16][17][18][19][20] The limited follow-up periods are of particular concern given that MS is a disease characterized by a progressive course that typically spans many years.…”

Increased Relapse Activity for Multiple Sclerosis Natalizumab Users Who Become Nonpersistent: A Retrospective Study

“…Reasons for switching or discontinuing include tolerability (e.g., skin reaction, injection site reactions, and flu-like symptoms); safety (e.g., allergic reaction, elevations in liver enzymes, depression, and immediate postinjection reaction); lack of efficacy (e.g., no perceived benefit); and burden (e.g., injection frequency). [6][7][8] To maximize the benefits of DMTs, MS patients must be persistent and adherent to their prescribed therapies. Persistence is a measurement of medication behavior and has been defined as "the duration of time from initiation to discontinuation of a therapy."…”