Evidence for Long-Term Use of Intramuscular Interferon Beta-1a: An Overview of Relapse, Disability, and MRI Data from Selected Clinical Trials

Abstract

The treatment options for multiple sclerosis are rapidly changing. With the increasing number of products available to treat this disease, treatment decisions are becoming more complex. Over the years, diagnosis and assessment of treatment efficacy in multiple sclerosis have evolved, but the primary endpoints used to evaluate patients have remained relatively consistent. Relapse rates, magnetic resonance imaging parameters, and disability progression are all key considerations when assessing efficacy for multiple sclerosis treatments. As selection of therapy becomes increasingly complex for both patients and physicians, risk-benefit considerations that incorporate long-term efficacy and safety on an individualized basis will be of greater importance. The information provided in this article will help to elucidate these considerations. • Multiple sclerosis (MS) is a chronic, immune-mediated neurologic disease that is associated with progressive disability and diminished quality of life by interfering with a person's ability to work, pursue leisure activities, and conduct typical life activities.• Several approved disease-modifying therapies (DMTs) are available to treat MS. These DMTs have demonstrated efficacy in key traditional MS outcome measures, including relapses, disability progression, and magnetic resonance imaging (MRI) measures.• This article provides an overview of the key traditional outcomes assessed in MS studies and critically evaluates phase 3 and longterm follow-up outcomes data for intramuscular interferon beta1a (IM IFNβ-1a), one of the frequently prescribed treatments for patients with MS.• IM IFNβ-1a administered once weekly has demonstrated efficacy in reducing relapse rates, disability progression, and disease activity visible on MRI in multiple MS studies.• IM IFNβ-1a has been an effective first-line treatment option for patients with MS for more than 15 years. Its efficacy and safety profiles have been well established in the post-marketing setting, and no new safety considerations have emerged. The adverse reactions most commonly reported in patients associated with the use of IM IFNβ-1a are flu-like symptoms occurring within hours to days following an injection. Summary Points Presented in this ArticleMS will result in significant changes in treatment. Fingolimod is the most recently approved DMT for treatment of relapsing forms of MS, and several other drugs are currently in late-stage development. The pivotal studies for these latest therapies, which include laquinimod, 27,28 teriflunomide, 29-31 dimethyl fumarate (BG-12), 32,33 alemtuzumab, 34 and PEGylated interferon beta-1a, 35 have primary endpoints (relapse rates, disability progression, MRI activity) similar to those used in the registration trials of currently approved DMTs.Because traditional measures of efficacy in MS do not capture other important aspects of the disease, additional measures, including the Multiple Sclerosis Functional Composite (MSFC), cognition, and quality of life (QoL), as well as newer imaging t...

Interferon Beta-1a (AVONEX®) as a Treatment Option for Untreated Patients with Multiple Sclerosis (AXIOM): A Prospective, Observational Study

“…In the AXIOM trial, the relapse rate was markedly lower during prospective treatment with IM IFNb-1a (0.2 per quarter on average) compared to retrospective data reflecting the three-month period prior to enrolment (1.1), when the majority of patients did not receive DMTs. The observational, non-controlled AXIOM trial tends to support the results of most, but not all previous studies [ 2 , 3 , 17 , 25 , 26 , 27 , 28 , 29 , 30 ], suggesting that the disease course is worse when treatment initiation of DMTs is delayed or treatment is interrupted for longer periods of time.…”