Background/Purpose: Up to 30% of patients with incident pericarditis will develop recurrent pericarditis (RP), with severe impact on quality of life. More than 20% of these patients have concurrent autoimmune disease, and this subgroup is at particularly high risk for recurrence. RHAPSODY established that IL-1 pathway inhibition with rilonacept is highly effective in preventing episodes of RP for idiopathic or post-pericardiotomy etiologies. This study aimed to investigate the efficacy and safety of rilonacept in the autoimmune RP subgroup.

Methods: This is a single-center retrospective case series of consecutive patients with incident or RP and underlying autoimmune disease who initiated rilonacept at any time between 7/2022 to 1/2024 at an academic tertiary referral center. Patients were included if they met ESC criteria for recurrent, incessant, or incident pericarditis at the time of rilonacept initiation.

Results: A total of 16 patients were followed for 1.6 (IQR 1.2-2.2) years after rilonacept initiation. Time elapsed from first pericarditis episode to rilonacept initiation was 8.8 (IQR 0.1-19.5) months, with 2.5 (IQR 1-4) prior flares. Sjogren’s syndrome was diagnosed in 14 patients, SLE in 2, and sarcoidosis/Sjogren’s in 1. Out of 16 patients, 4 had preceding autoimmune disease, diagnosed a median 15 months prior to their first pericarditis episode.During the RP episode that led to rilonacept initiation, CRP was elevated in 100% of patients to a mean 173.8 +/- 120.4 mg/L. Corticosteroids were used for RP in 12 (75%), and 13 (81%) were treated with colchicine. Additional patient characteristics are described in Table 1. Both patients with SLE were prescribed HCQ and mycophenolate throughout the follow-up period.The duration of rilonacept treatment was 1.5 (IQR 0.8-2.2) years. No recurrences were observed in patients while on treatment. There were no adverse events related to rilonacept reported to providers during the follow-up period. All 12 patients treated previously with corticosteroids for RP were able to taper entirely off.A total of 2 patients withdrew from rilonacept prior to data cutoff, one with SLE and one with Sjogren’s (range 8.3-9.0 months post-initiation), both due to patient preference. These patients remained recurrence free over a mean 1.2 years of follow-up after discontinuation of rilonacept.

Conclusion: IL-1 pathway inhibition with rilonacept in the autoimmune RP subgroup was associated with complete abrogation of RP episodes. Further research should establish the optimum duration of treatment in the high-risk autoimmune RP cohort, evaluate the safety profile of rilonacept with concomitant DMARD therapy, and assess the efficacy of treatment in a broader spectrum of autoimmune conditions.

Table 1. Patient Characteristics at Rilonacept Initiation

ACR Meeting Abstracts - https://acrabstracts.org/abstract/recurrent-or-incident-pericarditis-with-concurrent-autoimmune-disease-stable-control-with-rilonacept-interleukin-1-pathway-inhibition/