Sutej, Paul

Background Rilonacept, a once‐weekly interleukin‐1 alpha and beta cytokine trap, reduced pericarditis recurrence in the phase 3 study, RHAPSODY (Rilonacept Inhibition of Interleukin‐1 Alpha and Beta for Recurrent Pericarditis: A Pivotal Symptomatology and Outcomes Study). The RHAPSODY long‐term extension further explored recurrent pericarditis natural history and treatment duration decision‐making during 24 additional months of open‐label rilonacept treatment. Methods and Results Seventy‐four patients commenced the long‐term extension, with a median (maximum) total rilonacept duration of 22 (35) months. Individually, 18 months after the most proximal pericarditis recurrence, investigators decided to continue rilonacept on study, suspend rilonacept for off‐treatment observation (rescue allowed), or discontinue the study. The annualized incidence of pericarditis recurrence on rilonacept up to the 18‐month decision milestone was 0.04 events/patient‐year versus 4.4 events/patient‐year prestudy while on oral therapies. At the 18‐month decision milestone, 64% (33/52) continued rilonacept, 15% (8/52) suspended rilonacept for observation, and 21% (11/52) discontinued the study. Among the 33 patients (1/33; 3.0%) continuing rilonacept (median time to recurrence could not be estimated due to too few events), a single recurrence occurred 4 weeks after a treatment interruption. Among patients suspending rilonacept, 75% (6/8) experienced recurrence (median time to recurrence, 11.8 weeks [95% CI, 3.7 weeks to not estimable]). There was a 98% reduction in risk of pericarditis recurrence among patients continuing rilonacept treatment after the 18‐month decision milestone versus those suspending treatment for observation (hazard ratio, 0.02; P <0.0001). Conclusions In the RHAPSODY long‐term extension, continued rilonacept treatment resulted in continued response; treatment suspension at the 18‐month decision milestone was associated with pericarditis recurrence. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03737110.

Introduction: Rilonacept reduced pericarditis recurrence in the phase 3 trial RHAPSODY. The long-term extension (LTE) enabled further insights into efficacy, safety, and clinical decision making. Methods: The RHAPSODY run-in (RI) and randomized-withdrawal periods were followed by an LTE that enabled open-label rilonacept treatment up to 24 additional months. A decision at 18 months after the most recent recurrence was based on clinical status at investigator discretion: 1) continue rilonacept on-study, 2) suspend rilonacept for observation or 3) discontinue from the LTE without observation. Endpoints included recurrence and quality of life. Results: In May 2020, 74 of 75 eligible subjects continued to LTE; US subjects (n=45) switched to commercial therapy or discontinued in April 2021 (treatment duration from RI baseline [median; maximum] 18; 27 months). Non-US subjects (n=29) completed the LTE in June 2022 (treatment duration from RI baseline [median; maximum] 27; 33 months). Concomitant oral medications during LTE: 22% NSAIDS, 20% colchicine, 0% corticosteroids, 43% none. Inflammation signs (CRP), RP symptoms (PGIPS), and recurrences were low on-treatment. Before the 18-month decision (n=74), there were 3 investigator-assessed recurrences (0.04 per patient-year). At the 18-month decision (n=52), 64% (n=33) continued rilonacept on-study, 15% (n=8) suspended rilonacept for observation, and 21% (n=11) discontinued the study without observation, of whom 7 switched to commercial rilonacept. There was a 75% recurrence rate (n=6/8) in the off-treatment observation group (median time to event 11.8 [3.7, Not-Estimable (NE)] weeks) but only 1 recurrence in subjects on rilonacept (time to event NE [too few events]) associated with a 4-week interruption; HR 0.018, p<0.0001; Fig 1. Conclusions: Continued rilonacept treatment resulted in continued treatment response, whereas treatment suspension at 18 months may be associated with pericarditis recurrence.

Abstract Aims In this protocol-predefined substudy of the RHAPSODY trial, the primary aim was to assess whether pericardial late gadolinium enhancement (LGE) was associated with time to pericarditis recurrence. Methods and results RHAPSODY was a Phase 3 double-blind, placebo-controlled, randomized-withdrawal trial that demonstrated the efficacy of rilonacept in recurrent pericarditis (RP). Patients with a history of multiple RP and an active recurrence were enrolled and had the option to participate in a cardiac magnetic resonance (CMR) imaging substudy. CMRs were interpreted by a blinded independent core laboratory with prespecified criteria to define pericardial LGE. Compared to patients with trace or mild pericardial LGE (n = 9), patients with moderate or severe pericardial LGE (n = 16) generally had a higher number of recurrent episodes per year (5.3 vs. 3.9) and a higher mean CRP level (3.6 vs. 1.1 mg/dL). Overall, 10/14 (71.4%) who received a placebo had a recurrence compared to 0/11 (0%) who received rilonacept. In patients randomized to placebo who had moderate or severe pericardial LGE, the median time to recurrence was 4.2 weeks compared to 10.7 weeks in patients who had trace or mild pericardial LGE. At the conclusion of the event-driven randomized-withdrawal period, among patients receiving a placebo, 5/7 (71.4%) with trace or mild pericardial LGE and 5/7 (71.4%) with moderate or severe pericardial LGE had a recurrence. Conclusions Among patients with multiple RP, these preliminary findings support the concept of pericardial LGE as an imaging biomarker that may inform the duration of treatment and risk of recurrence with cessation of therapy and larger studies should be considered. ClinicalTrials.gov Identifier NCT03737110