The present study aims to assess the adherence to therapy with interferon beta-1a (Rebif®) and at investigating potential factors that are involved in its outcome, in a representative sample of patients with relapsing remitting multiple sclerosis (RRMS), under real life conditions.

In the relapsing-remitting type of the disease the objective of the therapy is the reduction of relapse rate, duration and severity, as well as the delay of transition to the progressive form of the disease. Subjects' adherence to long-term therapy of MS plays a pivotal role in the optimization of therapeutic outcome and maximization of the derived clinical benefit for the treated subjects. Rebif current formulation has been developed by assessing and refining the physicochemical characteristics of existing formulations aiming at further improving product's tolerability profile. Studies performed for the assessment of Rebif have demonstrated a 3-fold reduction in injection site reactions as well as improved overall tolerability and safety profile.

This is a multicentre, prospective, non interventional, non randomized, open label study for the assessment of the adherence to therapy with Rebif of subjects with RRMS. The participating subjects shall be already on treatment with (Rebif) prior to their enrolment into the study, according to the approved Summary of Product Characteristics (SPC) and the clinical, imaging and laboratory findings of the disease, as evaluated by their treating physician, in real life clinical practice. Data will be collected retrospectively from a sample of 150 subjects' medical files and through questions that will be posed to the subjects, and prospectively during the course of the study. The total duration of the study is estimated to be 18 months.

OBJECTIVES

Primary objective:

• To assess the compliance and persistence with Rebif therapy in MS subjects, after six months of therapy, in "real life" clinical settings in Greece

Secondary objective:

• To investigate the potential factors influencing compliance and persistence to Rebif therapy.

Inclusion Criteria:

• Subjects with documented diagnosis of RRMS according to the Mc Donald criteria (2005)
• Subjects who have already been administered therapy with IFN b-1a (Rebif) according to the approved product's Summary of Product Characteristics (SPC), at least two weeks and not longer than six weeks prior to their enrolment into the study
• Subjects of both genders, aged between 18 - 65 years (inclusive)
• Expanded Disability Status Scale (EDSS) score < 6 (inclusive) at baseline (before Rebif therapy initiation)
• Subjects who are able to read and understand the Patient Information Leaflet
• Subjects who have signed the Informed Consent Form
• Subjects who are willing and capable to comply will all study requirements and procedures.

Exclusion Criteria:

• Subjects that meet any of the contraindications to the administration of the study drug according to the approved SPC
• Subjects with primary progressive or secondary progressive form of MS
• Subjects who have been treated with Rebif for less than two weeks and more than six weeks before their enrollment into the study
• Subjects who had been receiving any therapy for MS (other disease modifying drugs, immunomodulatory and/or immunosuppressive agents) within three months before Rebif therapy commencement
• History of any chronic pain syndrome
• Current or past (during the preceding two years) history of alcohol or drug abuse
• Women who are pregnant or breastfeeding or of childbearing potential that do not use any medically accepted method of contraception
• Subjects who are currently participating or had participated in another clinical trial during the last three months prior to their enrolment

Subjects with documented diagnosis of RRMS according to the McDonald criteria (2005)