title: The STAR Study: a real-world, international, observational study of the safety and tolerability of, and adherence to, serum-free subcutaneous interferon β-1a in patients with relapsing multiple sclerosis.
abstract: BACKGROUND
  Adverse reactions, particularly injection site reactions (ISRs), are common reasons for nonadherence to injectable multiple sclerosis (MS) treatments. Adherence to MS treatment is important to ensure good treatment outcomes.
  
  
  OBJECTIVE
  The aim of this study was to assess the local tolerability of subcutaneous (SC) serum-free interferon (IFN) β-1a in patients with relapsing MS over 1 year in a real-life, international setting. The study also assessed safety, disease activity, and adherence.
  
  
  METHODS
  This was a prospective, international, multicenter, observational study of 251 patients with relapsing-remitting MS treated with SC serum-free IFN β-1a 44 μg or 22 μg 3 times weekly for 12 months or until early discontinuation. The primary end point was the proportion of patients with ISRs. Secondary end points included proportion of patients with adverse events (AEs); annualized relapse rate (ARR); proportion of patients remaining relapse-free; and adherence to treatment.
  
  
  RESULTS
  During the observation period, 27.5% (69 of 251) of patients experienced nonserious ISRs, which was consistent with the incidence reported in clinical studies. Five patients discontinued treatment and 2 patients suspended treatment because of ISRs. Mean age was 35.8 years; patients were predominantly white (94.8%), and two thirds (66.1%) were female. The overall incidence of AEs was 63.7% (160 of 251), and overall safety and tolerability were assessed as excellent, very good, or good in >85% of patients. More than 70% of patients remained relapse-free, and the mean ARR was 0.4. More than 90% of patients had very good or good adherence to treatment; a significantly greater proportion of these were relapse-free at 12 months compared with those with fair or poor adherence (77.6% vs 50.0%; P = 0.0107), and their ARR was significantly lower (0.3 vs 0.9; P = 0.0055). Patients with fair or poor adherence had 4.6 times higher odds of experiencing a relapse than those with very good or good adherence.
  
  
  CONCLUSIONS
  The incidence of ISRs and the overall safety profile in this observational study, in an international population in a real-life setting, confirm the good local tolerability of SC serum-free IFN β-1a reported in clinical studies. The association between good adherence and a lower ARR underlines the importance of good adherence. The good local and general tolerability of SC IFN β-1a may help ensure a high level of adherence, which is associated with better clinical outcomes. ClinicalTrials.gov identifier: NCT01080027.
authors.affiliation: Orbis Medical Centre, Sittard-Geleen, Maastricht University Medical Centre, the Netherlands. Electronic address: r.hupperts@orbisconcern.nl.
authors.forename: Raymond
authors.initials: R
authors.lastname: Hupperts
authors.affiliation: Merck BV Schiphol-Rijk, the Netherlands.
authors.forename: Lizette
authors.initials: L
authors.lastname: Ghazi-Visser
authors.affiliation: Department of Neurology, Centro-Hospitalar do Porto-Hospital de Santo Antonio, Largo Abel Salazar, Oporto-Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Martins Silva
authors.affiliation: Merck AE Hellas, Marousi, Greece.
authors.forename: Michalis
authors.initials: M
authors.lastname: Arvanitis
authors.affiliation: Kanta-Häme Central Hospital, Hämeenlinna and Tampere University Hospital, Tampere, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Kuusisto
authors.affiliation: Merck Gesellschaft mbH, Vienna, Austria.
authors.forename: Kurt
authors.initials: K
authors.lastname: Marhardt
authors.affiliation: 3rd Neurological Clinic, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Vlaikidis
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D000068556:Interferon beta-1a / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D010349:Patient Compliance; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000068556:Interferon beta-1a
keywords: adherence; injection site reactions; injection subcutaneous; interferon β-1a