Abstract 47: Tapering And Discontinuation Of Background Therapies During The Transition To Rilonacept Monotherapy In Rhapsody, A Phase 3 Clinical Trial Of Rilonacept In Patients With Recurrent Pericarditis

Background: Post-episode tapering of Standard of Care (SoC) medication in patients with recurrent pericarditis (RP) varies considerably. Gradual tapering of corticosteroids (CS) is recommended in ESC guidelines (decreasing by 1-2.5 mg/day every 2-6 weeks over 1-2 years) to prevent recurrence. We describe successful faster tapering of SoC treatment onto rilonacept monotherapy during RHAPSODY, a Phase 3, placebo-controlled, randomized-withdrawal (RW) trial in RP. Methods: Patients with acute symptomatic RP despite stable doses of NSAIDs, colchicine, and/or CS in any combination enrolled in a 12-week run-in period in which weekly rilonacept was initiated. After 1-week of stabilization, tapering of CS began at a rate dependent on baseline dose, to be completed by Week 10 for randomization at Week 12 when clinical response was confirmed by reduced pain and normalized CRP levels. Colchicine tapering/discontinuation was initiated no earlier than Week 4. This analysis evaluates time to rilonacept monotherapy in subgroups receiving different combinations of background therapies. Results: 79 of 86 patients were receiving pharmacotherapy at run-in baseline. Median (95% CI) time to monotherapy (n=79) was 7.9 (7.0-8.1) weeks. Of the patients receiving CS at baseline (41/86 [48%]), 39 (95%) tapered to rilonacept monotherapy, and median time to monotherapy was 7.9 (7.1-8.1) weeks. Of the patients receiving colchicine at baseline (65/86 [76%]), 61 (94%) patients achieved rilonacept monotherapy, and median time to monotherapy was 8.0 (7.1-8.3) weeks. Patients receiving only one SoC therapy achieved rilonacept monotherapy faster (6.1 [0.4-8.1] weeks) than those receiving 2 (8.0 [6.7-9.9] weeks) or 3 (7.7 [7.0-8.3] weeks) therapies. All patients who did not achieve monotherapy had withdrawn from the study for reasons unrelated to pericarditis. Conclusion: All patients randomized in the RHAPSODY trial discontinued SoC and transitioned to rilonacept monotherapy (median time 7.9 weeks) without a recurrent pericarditis episode during run-in. With rilonacept, time to successful discontinuation of SoC, including high dose CS, was substantially more rapid than current treatment practices. RHAPSODY data helped support FDA approval of the first therapy for RP.