• BACKGROUND
    • Axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) are chronic inflammatory diseases that often cause joint damage, potentially leading to joint replacement surgery. We assessed whether Janus kinase (JAK) inhibitors reduce the risk of total knee or hip replacement compared to nonsteroidal anti-inflammatory drugs (NSAIDs).
  • METHODS
    • Using the Merative™ MarketScan® Commercial Database, we conducted a nested case-control study of adults aged 18-65 years with axSpA and/or PsA from October 2015 to December 2021. Medication exposure was categorized hierarchically using pharmacy and procedure claims, including JAK inhibitors, non-tumor necrosis factor inhibitor biologics (non-TNFi biologics), TNF inhibitors (TNFi), DMARDs, NSAIDs (referent), and none. Logistic regression with confounder adjustment assessed associations between medication class and joint replacement risk.
  • RESULTS
    • Among 8855 eligible adults, 1771 cases of joint replacement were identified. JAK inhibitor use was not significantly associated with reduced odds of joint replacement compared to NSAIDs (odds ratio [OR] 0.67, 95% confidence interval [CI] 0.41-1.08). Non-TNFi biologic users (OR 0.66, 95% CI 0.53-0.82), TNFi users (OR 0.63, 95% CI 0.52-0.76), and DMARD users (OR 0.65, 95% CI 0.53-0.80) had lower odds of joint replacement than NSAID users.
  • CONCLUSION
    • We did not find conclusive evidence that relative to NSAIDs, JAK inhibitors prevent end-stage arthritis requiring surgery in axSpA and PsA; however, risk was reduced with use of non-TNFi biologics, TNFi, or DMARDs. Longer-term data are needed to understand the optimal utilization of JAK inhibitors in preventing end-stage arthritis in these conditions. Key Points • Axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) are chronic inflammatory diseases that often cause joint damage, potentially leading to joint replacement surgery. • In our study, although there was not conclusive evidence that JAK inhibitors prevent end-stage arthritis requiring surgery in axSpA and PsA relative to NSAIDs, we did find that risk was reduced with use of non-TNFi biologics, TNFi, or DMARDs. • Understanding the impacts of different medication classes, including Janus kinase (JAK) inhibitors and tumor necrosis factor inhibitors (TNFi) relative to nonsteroidal anti-inflammatory drugs (NSAIDs) may guide treatment decisions.