Rheumatoid arthritis (RA) is an autoimmune disease characterised by persistent inflammation of the synovial joints as well as other tissues and organs. Left untreated, it can lead to joint damage, disability and even increased mortality. The disease is driven by inflammatory cytokines that contribute to the chronic inflammation seen in RA. Interleukin-6 (IL-6) is a key pathological cytokine and a target for treatments aiming to alleviate local and systemic inflammation. Despite advances in understanding RA and the introduction of new treatments, achieving sustained remission remains challenging. This review explores the role of IL-6 in RA pathogenesis, its potential as a treatment target and the significance of personalised medicine in RA management. IL-6 has a dual signalling mechanism, classical and trans-signalling, which influences various intracellular pathways. While several targeted therapies have emerged, no single mechanism-based therapy is universally effective due to the diversity and complexity of the disease. Different approaches to targeting IL-6 have been tested, including biologic blockade of receptors or ligands, and inhibition of IL-6 signalling. IL-6 receptor inhibitors have been validated as RA therapeutics, either alone or in combination with other treatments. Tocilizumab, the first approved IL-6 inhibitor, blocks both soluble and membrane-bound IL-6 receptors, reducing the inflammatory cascade. Clinical trials confirm the efficacy and safety of tocilizumab and its role as a treatment option for patients unresponsive to conventional therapies. The benefits of IL-6 inhibition extend beyond reduced joint inflammation to the amelioration of comorbidities like anaemia, cardiovascular disease, depression and osteoporosis. Tailoring treatment to patients' profiles and comorbidities is essential for optimal outcomes. A 'treat-to-profile' approach, focusing on a holistic view of the patient, could improve personalised medicine strategies. Biosimilars - lower-cost alternatives to biologics - further enhance the accessibility and cost-effectiveness of treatment. IL-6 inhibitors present a valuable treatment option for RA management, particularly for patients with specific comorbidities.
Keywords: biological therapy; interleukin-6; personalized medicine; rheumatoid arthritis.
What have we learnt from the inhibition of IL-6 in RA and identifying the clinical opportunities for patient outcomes? Rheumatoid arthritis (RA) is a condition where joints become swollen and painful due to long-term (chronic) inflammation. If left untreated, it can cause severe joint damage, disability and even increase the risk of death. The disease is driven by cytokines, which are proteins in the body that help control the immune system and can cause inflammation. One important cytokine is interleukin-6 (IL-6), and scientists are studying ways to block its effects to help people with RA. This review looks at how IL-6 works in RA and how blocking it might help. Despite new treatments, it is still hard to fully control RA. Researchers are trying to find better ways to personalise treatments based on the symptoms of individual patients. One drug called tocilizumab stops IL-6 from working by attaching to its receptor. A receptor is a part of a cell that receives signals from substances like cytokines. When IL-6 attaches to its receptor, it triggers inflammation. Tocilizumab stops IL-6 from attaching to its receptor, reducing pain and inflammation in people with RA. This drug not only helps the joints but may also improve other problems like anaemia, heart disease and even depression that often come with RA. The review suggests that treating RA should involve looking at the person’s overall health, not just the joints. IL-6 blockers might be particularly useful for patients with other health issues or for those who have not responded well to other treatments. Biosimilars, which are similar to the original IL-6 blocking drug but less expensive, have expanded the treatment options. Combining personalised treatments with more affordable options could help improve the lives of people with RA. Overall, IL-6 blockers seem to be a promising way to help people with RA, especially when used in a personalised approach that considers the whole person and their overall health.
© The Author(s), 2024.