Sporadic Inclusion Body Myositis (IBM) is the most frequent inflammatory myopathy in patients over 50. It is a slowly progressive, but today untreatable (notably by classical immunosuppressants) disease.

Rapamycin used in organ transplantation blocks the activity of T effector cells, preserves T regulatory cells and induces autophagy (protein degradation), all parameters impaired during IBM.

RAPAMI is a prospective, randomised, controlled, double blind, monocentric, phase IIb trial evaluating rapamycine against placebo.

Inclusion Criteria:

• IBM defined by the Benveniste & Hilton-Jones ( Neuromuscul Disord. 2010;20: 414-21) or Llyod criteria (Neurology 2014; 83: 426-433)

Exclusion Criteria:

• Impossiblility to walk 10 meters
• Hypersensitivity to rapamycin or one compound of the oral solution
• Severe respiratory insufficiency (FVC < 50% and/or FEV1 < 50%)
• Severe chronic kidney disease (Estimated Glomerular Filtration Rate < 15 ml/min and/or proteinuria > 0.3 g/24h)
• Chronic liver disease (cirrhosis and/or ALT/AST > 2.5 normal values)
• Cancer non in remission (necessitating specific treatment) during the past 12 months
• Connective Tissue Disease non in remission (necessitating specific treatment) during the past 12 months
• Pregnancy
• Seropositivity for HIV, HCV or HBV
• Total cholesterolemia > 8 mmol/l
• Triglyceridemia > 5 mmol/l
• Hemoglobinemia < 11 g/dL
• Thrombopenia < 100 000/mm3
• Neutropenia < 1500/ mm3
• Lymphopenia < 1000/ mm3