A Phase 1/2 study to test how effective different doses of MEDI-551 is for treating subjects with Relapsing-Remitting Multiple Sclerosis

INTERVENTION: Product Name: MEDI‐551 Product Code: MEDI‐551 Pharmaceutical Form: Concentrate for solution for infusion Current Sponsor code: MEDI‐551 Concentration unit: mg/ml milligram(s)/millilitre Concentration type: equal Concentration number: 10‐ Pharmaceutical form of the placebo: Concentrate for solution for infusion Route of administration of the placebo: Intravenous use Trade Name: Avonex Product Name: Avonex Pharmaceutical Form: Solution for infusion in pre‐filled syringe INN or Proposed INN: interferon beta‐1a CAS Number: 220581‐49‐7 Concentration unit: µg/ml microgram(s)/millilitre Concentration type: equal Concentration number: 60‐ CONDITION: Relapsing‐Remitting Multiple Sclerosis ; MedDRA version: 14.1 Level: PT Classification code 10063399 Term: Relapsing‐remitting multiple sclerosis System Organ Class: 10029205 ‐ Nervous system disorders Therapeutic area: Diseases [C] ‐ Nervous System Diseases [C10] PRIMARY OUTCOME: Main Objective: 1) To evaluate the safety and tolerability of ascending doses of MEDI‐551 in adult subjects with RRMS (Phase 1) ; 2) To compare the effect of MEDI‐551 versus Avonex on the proportion of relapse free subjects at Week 48 (Phase 2); Primary end point(s): Phase I ‐ To evaluate the safety and tolerability of ascending doses of MEDI‐551 in adult subjects with relapsing‐remitting multiple sclerosis (RRMS); ; Phase II ‐ To compare the effect of MEDI‐551 versus Avonex on the proportion of relapse free subjects; Secondary Objective: 1) To compare the effect of MEDI‐551 versus Avonex on the mean cumulative Gd enhanced MRI T1 brain lesions at Weeks 24 and 48 (Phase 2); 2) To evaluate the effect of MEDI‐551 on the Symbol Digit Modalities Test (SDMT; Phase 1/Phase 2); 3) To evaluate the PK and IM of MEDI‐551 in the subject population (Phase 1/Phase 2); 4) To describe the PD effect of MEDI‐551 by assessing B‐cell depletion/repletion in the peripheral blood (Phase 1/Phase 2); 5) To evaluate the safety of MEDI‐551 (Phase 2) Timepoint(s) of evaluation of this end point: Phase I ‐ Day 1 to Day 169; ; Phase II ‐ Day 337; SECONDARY OUTCOME: Secondary end point(s): ‐ To compare the effect of MEDI‐551 versus Avonex on the mean cumulative gadolinium enhancing lesion(s) ; ‐ To evaluate the effect of MEDI‐551 on the Symbol Digit Modalities Test (SDMT) ; ‐ To evaluate the pharmacokinetics (PK) and immunogenicity (IM) of MEDI‐551 in the subject population ; ‐ To describe the pharmacodynamic (PD) effects of MEDI‐551 ; ‐ To evaluate the safety of MEDI‐551 ; Timepoint(s) of evaluation of this end point: Day 1 to Days 169/337 INCLUSION CRITERIA: ‐Confirmed Relapsing‐Remitting Multiple Sclerosis (RRMS) according to revised 2010 McDonald criteria and brain lesions consistent with MS ‐At least 2 documented relapses within the past 3 years prior to screening or at least one documented relapse within 1 year prior to screening ‐Kurtzke Expanded Disability Status Scale (EDSS) between 0.0 and 5.0 at screening ‐At least 1 but not more than 15 gadolinium enhancing lesion(s)by cranial MRI at screening ‐Subjects that have 0‐15 gadolinium enhancing lesion(s) ‐ Male and female subjects must be willing to use effective methods of contraception ‐Willing to forego other forms of experimental treatment for RRMS during the study ‐Adequate peripheral venous access Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range 512 F.1.3 Elderly (>=65 years) no F.1.3.1 Number of