(021) Line of Therapy of Biologics and JAK Inhibitors in RA, PsA, and AxSpA: Implications for Design and Uptake of New Drugs and Diagnostics

Background: Patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (AxSpA) have an increasing array of treatment options available, and new blood-based diagnostic tests to predict future treatment response are commercially available or are in development. Moreover, certain medications are restricted to patients who are already biologic-experienced.

Objectives: To examine the point prevalence of the line of therapy (LoT) by type of arthritis to assess the size of the eligible patient population.

Methods: We queried the data warehouse of the Excellence Network in Rheumatology (ENRGY), a national practice-based research network (PBRN), to identify patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (AxSpA). Data from the electronic health record (EHR) was linked to a custom in-office tablet app that captures patients’ lifetime treatment history, disease duration and other disease features. We compared agreement across both data sources to identify current users of conventional, biologic, or targeted synthetic DMARDS (cs/b/tsDMARDs) and classify them as to their prior treatment history over their lifetime. Results were reported by disease and by medication class.

Results: As of Q4 2022, we identified 6740 RA, 1889 PsA, and 543 AxSpA patients who had linked EHR and self-reported lifetime treatment history data available who were current users of any cs/b/tsDMARDs. The proportion of patients who were biologic and JAKi naïve was 34% in RA, 10% in PsA, and 9% in AxSpA. The proportion of patients who were biologic naïve or treatment-experienced with only 1 current or past biologic or JAKi was 62% in RA, 22% in PsA, and 28% in AxSpA. Comparison of EHR data and patient self-report showed 61% agreement in reported prior use across both methods (weighted kappa = 0.58; SD[0.57,0.60]).

Conclusions: Stakeholders interested in developing or marketing new therapies and diagnostic tests that target RA, PsA or AxSpA patients who are biologic naïve or minimally treatment-experienced will find these estimates informative as they evaluate the potential opportunity and size of the eligible patient population.