IL-1 Pathway Inhibition in Recurrent Pericarditis Management: Real-World Adoption of Corticosteroid Sparing in RESONANCE.

Background: Recurrent pericarditis (RP) guidelines recommend second-line corticosteroids after aspirin/nonsteroidal anti-inflammatory drugs/colchicine, but complications of protracted use underscore the importance of corticosteroid-sparing strategies.

Objectives: Given clinical trial evidence supporting interleukin (IL)-1 pathway inhibition and US Food and Drug Administration approval of rilonacept in RP, the objective was to assess temporal trends in corticosteroid-sparing treatment of RP in a multicenter registry.

Methods: RESONANCE (REgiStry Of the NAtural history of recurreNt periCarditis in pEdiatric and adult patients; NCT04687358) combines retrospective and prospective data from clinical practice into a single observation period. Patients receiving treatment for idiopathic and postprocedural RP were included. Demographics and treatment intensifications were quantified.

Results: Of 313 patients with aspirin/nonsteroidal anti-inflammatory drugs/colchicine treatment (median disease duration 1.9 years; 1 preenrollment recurrence), 44% (n = 138) intensified treatment. Before rilonacept approval in RP, 71% (n = 10) of patients intensified to corticosteroids for second-line therapy, and 29% (n = 4) intensified to IL-1 pathway inhibition. After rilonacept approval, the proportion of patients intensifying to second-line IL-1 pathway inhibition increased to 64% by 2023 (n = 27; rilonacept: 57%, anakinra: 7%), whereas the proportion of patients intensifying to corticosteroids decreased to 33% (n = 14), P = 0.02. Approximately 59% (n = 35) of second-line corticosteroid initiators later transitioned to IL-1 pathway inhibition. In patients starting second-line IL-1 pathway inhibition, 5% (n = 3, rilonacept) and 25% (n = 4, anakinra) subsequently used corticosteroids for >30 days.

Conclusions: In RESONANCE, IL-1 pathway inhibition increasingly replaced corticosteroids as second-line therapy. Most patients starting corticosteroids transitioned to IL-1 pathway inhibition; few transitioned from second-line IL-1 pathway inhibition to long-term corticosteroids. These findings may inform treatment algorithms and patient-provider decision-making.