Clinical evaluation of the safety, efficacy and tolerability of sarilumab in the treatment of moderate to severe rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that is characterised by synovial inflammation and progressive joint disorder with significant pain and stiffness, which lead to functional disability and systemic complications if left untreated. Although methotrexate (MTX) is the cornerstone in the RA therapy, it is ineffective or intolerable in up to 50% of patients. In addition, tumour necrosis factor (TNF) inhibitors which are regarded as the standard of care for those patients, have not been proven a panacea creating a therapeutic gap. In this direction, other cytokines such as the interleukin (IL)-6 in combination with MTX or as monotherapy have been approved. Sarilumab has already been approved for the treatment of moderate to severe RA, but more studies are on their way including polymyalgia rheumatica, giant cell arteritis, juvenile idiopathic arthritis, and indolent systemic mastocytosis. On the other hand, a study was prematurely discontinued after approximately 1.5 years, when the ankylosing spondylitis development program was discontinued due to lack of efficacy. Regarding safety, efficacy and tolerability of the molecule, three pivotal clinical trials have established sarilumab as one of the safe and efficacious choices for the treatment of RA (mobility, target and monarch trials). Significant decreases in progression of structural damage have been demonstrated. Infections and neutropenia are two of the most common adverse events. Sarilumab is beyond any doubt another molecule that can be added to the clinicians' armamentarium for the treatment of patients with moderate to severe RA with a good safety and efficacy profile.