This is a cross sectional Phase 4, multicenter, study of AVONEX® and JUMTAB® to determine the frequency of IFN induced Neutralizing Antibodies (Nabs). A secondary component is the long term retrospective observational evaluation conducted to measure efficacy, adherence to therapy, tolerability, and safety in subjects with relapsing MS related to antibody status and treatment.

The primary objective of this study is to evaluate the frequency of neutralizing antibodies in patients treated with IFN beta 1a IM (Avonex) and IFN beta 1a IM biosimilar formulation (Jumtab).

Secondary objectives:

• Evaluate the effect of Nabs on the severity of the relapses on each treatment group, measured by:

  • The need and duration of steroid courses
  • The need and duration for hospitalization.

• To evaluate the safety and tolerability of the IFN beta 1a IM treatments [Avonex and Jumtab].

• To identify the genetic profile of the patients with relation to the predisposition to Nab development (HLA DR4 (in particular HLADRB1* 0401 and 0408) and DR16 (in particular HLADRB1* 1601)

• At selected sites: To evaluate the influence of the interferon and the Nabs on the activation of neopterin

Inclusion Criteria:

• To be eligible for entry into this study, candidates must meet all of the following eligibility criteria at the time of selection:

  • No limitation of age, EDSS or other disease parameters will be applied.
  • Subject with MS
  • Subjects treated with IFN beta 1a IM (Avonex) or the biosimilar formulation of IFN beta 1a IM (Jumtab) in line with the local prescription information
  • The IFN beta 1a IM (Avonex or Jumtab) treatment should be the first disease modifying treatment
  • The subject should be treated with the same drug for at least 18 months and up to a maximum of 3 years

Exclusion Criteria:

• Candidates will be excluded from study entry if any of the following exclusion criteria exist at the time of selection:

  • No informed consent
  • Patients with combination therapy (IFN + immunosuppressive therapy)
  • Patients pretreated with immunosuppressive therapy
  • Treatment with any investigational product, including investigational symptomatic therapies for MS (e.g., 4Aminopyridine) and investigational therapies for NonMS indications, during the review period.

NOTE: subjects may receive investigational symptomatic therapies for MS at any time prior to evaluation period.