Immune Checkpoint Inhibitor-induced Inflammatory Arthritis: Current Approaches to Management

Abstract

The introduction of immune checkpoint inhibitors (ICI) has changed the landscape of treatment of cancer. As a consequence of immune activation, ICIs can cause immune-related adverse events (irAEs) affecting almost all organ systems. Several irAEs have now been described such as ICI-inflammatory arthritis (IA), sicca syndrome, polymyalgia rheumatica (PMR), myositis and vasculitis. The onset of the ICI-IA can vary from after the first infusion of ICIs to a delayed presentation a year or more after ICI initiation. Just as de novo IA is pleomorphic, several different forms of ICI-IA have been reported. Physical examination, lab and imaging tests can help the rheumatologist in determining the grade (severity) of arthritis. Corticosteroids tend to be the first line agent for treatment of ICI-IA with initial doses varying depending on the grade of the arthritis. For patients who are unable to taper steroids or who do not have a good clinical response, different forms of immunosuppression are required. Ultimately, baseline patient and tumor characteristics, the types of immunotherapies used (monotherapy versus combined therapies), pre-existing autoimmune diseases and/or other irAEs, as well as patient preferences will all shape the discussions around ICI-IA management. Engaging in multi-disciplinary discussions is needed when caring for this patient population.