Toward immune tolerance in rheumatoid arthritis: Emerging immunotherapies and targets for long-term remission

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that affects approximately 1 % of the global population. It is characterized by immune dysfunction leading to synovitis and joint damage. Despite advancements in biologic and personalized synthetic disease-modifying anti-rheumatic drugs (DMARDs), definitive solutions remain elusive. This review explores novel immunotherapies, such as antigen-specific tolerizing immunotherapy (ASITI) and immune checkpoint agonism, designed to retrain the immune system for sustained remission. ASITI-RA strategies specifically target autoreactive T and B cells while preserving immune competence, including tolerogenic dendritic cells (tolDCs), nanoparticle-based therapies, and soluble peptides. Clinical trials, including Rheumavax and calcitriol liposomes, demonstrate safety and immunomodulatory promise, particularly in early RA. Programmed cell death-1 (PD-1) agonists, like rosnilimab, show potential in restoring immune homeostasis by reducing pathogenic T cell responses. Furthermore, combining cell apoptosis protein (cIAP) inhibitors with tumor necrosis factor-alpha (TNF-α) inhibition reveals synergistic effects in preclinical models, suggesting extended therapeutic benefits. Challenges include patient classification, biomarker detection, and long-term safety. These therapies represent a paradigm shift from broad immunosuppression to targeted immune reprogramming, offering hope for antigen-specific, drug-free remission in RA.