Background/objectives Rilonacept (RI), an interleukin (IL)-1α/β cytokine trap, is a biological treatment to prevent recurrence in recurrent pericarditis (RP). Discontinuation of RI in patients after 18 months with RP has been associated with a higher rate of RP. We aimed to propose a preliminary strategy for stopping Rl in select patients and evaluate their long-term outcomes. Methods We conducted a retrospective cohort study at the pericardial disease centre at Cleveland Clinic, Ohio. Adults included had RP refractory to first-line therapies, receiving Rl for at least 12 months (median duration 24 months) with improvement in symptoms and late gadolinium enhancement on cardiac MRI. The primary outcome was recurrence of RP post abrupt Rl discontinuation versus slow taper (gradual decrease in Rl frequency from weekly, to bimonthly, to monthly and then cessation). We also evaluated the effects of colchicine prophylaxis at the end of Rl therapy, time to recurrence and the overall safety profile of long-term Rl therapy. Results A total of 53 patients were included in the study (61.8% female; mean age 54.6±14.17 y), of which 34 (62%) discontinued RI abruptly/without tapering and 19 (35%) underwent a RI taper after shared decision making with their clinician. A higher percentage of recurrent cases was observed in the abrupt cessation arm (82%) versus the taper arm (37%) (p=0.042). Treatment with colchicine post-completion of Rl therapy was associated with delaying the average time to flare by 60.7 weeks. Most patients (80%) resumed Rl after a recurrence. Long-term Rl therapy was well-tolerated during the follow-up period. Conclusions Long-term Rl therapy beyond 18–24 months leads to sustained disease remission in RP, and therapy withdrawal is associated with a recurrence in two-thirds of patients. A strategy that involves a gradual taper of RI therapy appears to be associated with a relatively lower risk of disease recurrence compared with discontinuation without tapering. Larger-scale, multicentre studies with extended follow-up periods are warranted to elucidate optimal treatment durations and to establish standardised cessation protocols.
