Wasserstrum, Yishay

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: Rare cardiac complications of COVID-19 and COVID-19 mRNA vaccination include pericarditis and myocarditis. Patients with recurrent pericarditis may be at increased risk of triggered recurrence. The known efficacy of the interleukin (IL)-1 antagonist rilonacept in treating and preventing recurrence could inform COVID-19 disease and vaccination management. Methods: The Phase 3 trial RHAPSODY was a global, double-blind, placebo-controlled, randomized-withdrawal study. A long-term extension (LTE) enabled up to 24 months further open-label treatment from May 2020 until June 2022. Concomitant vaccination data and adverse events, including COVID-19, were collected. Results: No COVID-19 cases were reported during the run-in and randomized withdrawal periods (n=86). As of the 6 May 2022 data cutoff, a COVID-19 AE was reported in 19% (14/74) of LTE subjects, of whom 12 were on rilonacept: 5 of 44 fully-vaccinated (≥14 days beyond second serial dose) subjects (11.4%) and 9 of 30 unvaccinated or partially-vaccinated subjects (30.0%). Of the fully-vaccinated subjects, 1 case occurred ~11 months post primary vaccination cycle (no booster). COVID-19 severity was mild (n= 11), moderate (n=2), or severe (n=1). All cases resolved except the severe AE complicated by comorbidities; the subject discontinued. Of 12 subjects receiving rilonacept at the time of COVID-19 diagnosis, 10 maintained dosing with rilonacept, 1 interrupted rilonacept for ~4 weeks, and 1 discontinued rilonacept permanently; none experienced a pericarditis recurrence (PR) after the AE. The remaining 2 subjects had previously interrupted rilonacept for off-treatment observation: one had a PR >4.5 months after suspending rilonacept and 18 days after COVID-19 resolution; no PR in the other (>6 months). There were no PR AEs associated with COVID-19 vaccination (all subjects were receiving rilonacept). Conclusions: In patients on rilonacept in this study, although numbers are small, vaccination reduced COVID-19 events, pericarditis recurrence was not increased by vaccination or disease, and no pericarditis recurrences occurred during rilonacept treatment. One pericarditis recurrence occurred remotely after rilonacept suspension in the peri-COVID-19 period.

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.