Phase 1:

Patients are treated with infusions of Tocilizumab (TCZ) for 3 months. Clinical evaluation is performed using PMR-AS.

The PMR-AS is computed by summing the 5 variables after multiplying by 0.1 for weighting purposes: PMR-AS (activity scale = AS) = C reactive protein (CRP) (mg/dl) + patient scale (VASp) (0-10 scale) + physician scale (VASph) (0-10 scale) + morning stiffness(MST) [min]×0.1) + elevation of upper limbs (EUL) (0-3 scale).

At the end of the phase 1,the patients stop TCZ and entered in phase 2 at week 12.

Phase 2:

All the patients are included in the phase 2 and treated with glucocorticoid (GC)for 3 months. Two arms are possible according to the PMR-AS. Either the classical GC treatment (0.3mg/kg), either a low dose group of GC(0.15mg/kg) .

Inclusion Criteria:

• Age between 50 years and 75 years included
• PMR-AS > 10
• PMR according to the Chuang criteria
• Evolving since less than 12 months
• Without Horton disease
• Able to understand and accept the study
• Agree to sign the inform consent form
• Without GC, or at least during 1 month and stop since 7 days before the inclusion.
• Stable dose of Nonsteroidal anti-inflammatory since 4 weeks before the inclusion.
• Birth controlled during all the study and 6 months after

Exclusion Criteria:

• Disagree to participated
• Unable to understand the study
• Participation to an other study in the 3 months before the inclusion
• Treated by GC at 0.3mg/kg/d in the past 7 days
• Less than 50 years old or more than 75 years old
• Uncontrolled dyslipidemia, high blood pressure or cardiovascular disease
• Histories of important allergy
• Historically positive test or test positive at screening for HIV-1 antibody, hepatitis B surface antigen, or hepatitis C antibody.
• Abnormal screening blood test : leukocyte count less than 3.5 × 109 cells/L, neutrophil count less than 2 × 109 cells/L, hemoglobin level less than 85 g/L, platelet count less than 100 × 109 cells/L, or hepatic aminotransferase or alkaline phosphatase levels greater than 3 times the upper limit of normal
• Other inflammatory rheumatic disease or connective disease
• Clinical evidence of significant unstable or uncontrolled acute or chronic diseases not due to PMR (eg. Cardiovascular, pulmonary, hematologic, gastrointestinal, hepatic, renal, neurological, malignancy or infectious diseases)
• Current drug or alcohol abuse
• Patients treated with an immunosuppressive agents in the past 4 weeks
• Live/attenuated vaccine in the past 4 weeks
• Clinical symptoms of giant cell arteritis
• History of infection or infestation in the past 3 months
• Active tuberculosis
• Planned surgical procedure
• History of malignant neoplasm within the last 5 years, except for adequately treated cancer of the skin (basal or squamous cell)
• History or current tumoral hematological disease
• Severe allergic or anaphylactic reactions about one of the TCZ component
• Pregnant women during the study and six month after the end of the study
• Breast feeding mother
• Dysthyroidia
• Unstable treatment by statin in the past 3 months
• Parkinson disease
• Fibromyalgia
• Peripheric arthritis
• Articular chondrocalcinosis or hydorxyapatites rhumatisms