A randomized, multicenter, two-arm, open-label, phase IIIb study to evaluate the satisfaction in relapsing Multiple Sclerosis subjects transitioning to Rebif® New Formulation (RNF) from Rebif® (Interferon beta-1a) with ibuprofen pro re nata (PRN) or as prophylaxis.

INTERVENTION: Trade Name: NA Product Name: Interferon‐beta 1a FBS‐free/HSA‐free, RNF Product Code: NA Pharmaceutical Form: Solution for injection INN or Proposed INN: Interferon beta‐1a CAS Number: 9008‐11‐1 Other descriptive name: recombinant human IFN beta Concentration unit: µg microgram(s) Concentration type: equal Concentration number: 44‐ Trade Name: Ibuprofen Sandoz 400 mg Filmtabletten Product Name: Ibuprofen Pharmaceutical Form: Tablet INN or Proposed INN: Ibuprofen Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 400‐ CONDITION: Relapsing multiple sclerosis ; MedDRA version: 9.1 Level: PT Classification code 10063399 Term: Relapsing‐remitting multiple sclerosis PRIMARY OUTCOME: Main Objective: To assess subject satisfaction by the MS Treatment Concern Questionnaire (MSTCQ) specifically measuring Flu Like Symptoms (FLS) during the first 4 weeks after subjects transitioned to RNF in 2 treatment groups: one treatment group receives ibuprofen prophylactically and the other ibuprofen PRN. Primary end point(s): The primary endpoint is the FLS score from the MSTCQ at week 4. This is defined as the sum of the scores for “side effects” section questions 1‐4, corresponding to a maximum total score of 20. Secondary Objective: To obtain clinical experience with the transition to RNF in order to provide physicians with recommendations how to best manage this transition through the use of concomitant ibuprofen. INCLUSION CRITERIA: Subject with Relapsing Forms of MS (RMS) EDSS score <‐ (equal or less than) 5.5 at study entry Subjects who have been administering Rebif 44mcg tiw for at least 6 months prior to study enrolment· Subject currently using Rebiject II and who will use own Rebiject II for the RNF injections Subject is between 18 and 60 years old inclusive Female subjects must be neither pregnant nor breast‐feeding and must lack childbearing potential, as defined by either: Post‐menopausal or surgically sterile, or Using a highly effective method of contraception. A highly effective method of contraception is defined as those which result in low failure rate (i.e. less than 1% per year) when used consistently and correctly such as implants, injectables, combined oral contraceptives, some IUDs (intrauterine devices), sexual abstinence or vasectomised partner. Subject is willing to follow study procedures Subject is willing and must not present any contra‐indicat