Treatment strategies for Spondyloarthritis: Implementation of precision medicine – Or “one size fits all” concept?

Spondyloarthritis (SpA) is a term to describe a group of chronic inflammatory rheumatic diseases, which have common pathophysiological, genetic, and clinical features. Under the umbrella term SpA, two main groups are subsumed: axial SpA (radiographic axSpA and non-radiographic axSpA) and peripheral SpA (with the leading representative being psoriatic arthritis (PsA) but also arthritis associated with inflammatory bowel disease (IBD), reactive arthritis, and undifferentiated pSpA). The key clinical symptom in axSpA is chronic back pain, typically with inflammatory characteristics, which starts in early adulthood, while the leading clinical manifestations of peripheral SpA (pSpA) are arthritis, enthesitis, and/or dactylitis. Furthermore, extra-musculoskeletal manifestations (EMMs) (acute anterior uveitis, psoriasis, and IBD) can accompany axial or peripheral symptoms. All these factors need to be taken into account when making treatment decisions in SpA patients. Despite the major advances in the treatment landscape over the past two decades with the introduction of biological disease-modifying anti-rheumatic drugs (bDMARDs) and most recently targeted synthetic DMARDs (tsDMARDs), a relevant proportion of patients still does not achieve the desired state of remission (=absence of disease activity). With this implementation of new treatment modalities, clinicians now have more choices to make in the treatment algorithms. However, despite generalized treatment recommendations, all factors need to be carefully considered when deciding on the optimal treatment strategy for an individual patient in clinical practice, aiming at an important first step towards personalized treatment strategies in SpA. In this narrative review, we focus on the efficacy of approved and emerging treatment options in axSpA and PsA as the main representative of pSpA and discuss their selective effect on the different manifestations associated with SpA to provide guidance on drivers of treatment decisions in specific situations.