Refining the Management of Rheumatoid Arthritis: the Benefits of Subcutaneous Tocilizumab

Rheumatoid arthritis (RA) is a chronic systemic autoimmune condition which affects approximately 1% of the adult population worldwide and is characterized by joint inflammation, with extra-articular features being common. Interleukin 6 (IL-6) is one of the chief pro-inflammatory cytokines found in the joints and sera of patients with RA. Increased levels of IL-6 correlate with inflammation, disease activity, and radiological damage. RA treatment should focus on minimizing the signs and symptoms of disease (pain, stiffness, and swelling of the joints) and on preventing or minimizing joint damage to preserve functionality and quality of life. The benefits of early, intensive intervention are now acknowledged, with all patients with newly diagnosed, active RA being started on methotrexate (MTX) monotherapy or combination therapy. Lack of efficacy, intolerance, and/or toxicity can lead to discontinuation of this drug, and there is a need for exploring further treatment options. In the UK, patients with persistently high disease activity who have failed at least two conventional disease-modifying agents (DMARDs) including MTX may qualify for biologic therapy. Numerous trials have shown intravenous (IV) tocilizumab (TCZ), a biologic drug targeting and inhibiting IL-6, to be effective for controlling inflammation in RA, with an acceptable safety profile. Its superiority in monotherapy when compared with other biologic agents makes it the drug of choice for patients who are intolerant or have contraindications to traditional DMARDs. However, one of the drawbacks of IV TCZ is the requirement for monthly infusions, which is inherently inconvenient for the patient and associated with increased cost. Subcutaneous (SC) TCZ has now been approved following two clinical trials which showed similar efficacy and safety compared to IV TCZ, and better efficacy compared to placebo (SUMMACTA and BREVACTA trials, respectively). Respiratory infections are the most common side effects in patients receiving SC TCZ. Advantages of SC formulations include convenience and reduced cost compared with IV therapies. Overall, patients tend to have a preference for SC over IV administration of medications. Close monitoring of patients should be undertaken in all cases, paying particular attention to the full blood count, liver enzymes, and cholesterol levels.