Wang, Sheldon

Abstract Aims In the Phase 3 trial, RHAPSODY, rilonacept effectively resolved active pericarditis recurrences, and long-term treatment led to sustained pericarditis recurrence risk reduction. Prior analysis suggested association between higher late gadolinium enhancement (LGE) at baseline and more rapid recurrence upon rilonacept suspension after 12 weeks of treatment. This subgroup analysis assessed the utility of longitudinal serial cardiac magnetic resonance (CMR) imaging for tracking clinical improvement and predicting post-treatment cessation outcomes to help guide clinical decision-making. Methods and results At an 18-month decision milestone (18MDM) in the RHAPSODY long-term extension, investigators decided if patients would continue rilonacept, suspend rilonacept for off-treatment observation, or discontinue the study. Pericardial thickness, pericardial oedema (T2-short tau inversion recovery, T2-STIR), and LGE were determined at baseline and 18MDM by an imaging core lab blinded to clinical data, and pericarditis recurrence was investigator-assessed. CMR results in patients with data at both baseline and 18MDM (n = 13) showed that pericardial thickness, T2-STIR, and LGE were reduced during rilonacept treatment. Among patients with CMR data who suspended rilonacept at the 18MDM (n = 7), five (71%) had a pericarditis recurrence within 1–4 months of rilonacept suspension, despite all having had none/trace LGE (n = 7) and negative T2-STIR (n = 7) at the 18MDM and two having received prophylactic colchicine. Conclusion Continued clinical improvement during prolonged rilonacept treatment corresponded with improvement on CMR, including reduced pericardial thickness, resolution of pericardial oedema, and resolution of LGE. However, none/trace LGE at 18MDM while on treatment did not predict absence of pericarditis recurrence upon subsequent rilonacept suspension in this size-limited subgroup.

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 treatment in RHAPSODY resolved active pericarditis recurrences, and long-term treatment led to sustained risk reduction. Prior analysis linked greater baseline Late Gadolinium Enhancement (LGE), with more rapid recurrence upon rilonacept suspension after 12 weeks of treatment. Serial cardiac magnetic resonance (CMR) imaging (T2-STIR, LGE) enabled longitudinal assessment for tracking clinical improvement, guiding decision-making, and predicting patient outcomes after treatment cessation. Methods: At the long-term extension (LTE) 18-month decision milestone (18MDM), investigators chose, based on clinical status, to continue rilonacept, suspend rilonacept/observe, or discontinue the LTE. An imaging core lab blinded to clinical data measured pericardial thickness and graded pericardial edema (T2-STIR) and LGE at baseline and 18MDM. Pericarditis recurrence was assessed clinically following rilonacept suspension. Results: Baseline and 18MDM CMRs were available for 13 patients. Reductions in pericardial thickness, T2-STIR, and LGE from baseline to 18MDM while on treatment are provided in Figure . CMRs were obtained in 7/8 patients suspending rilonacept at 18MDM: LGE was none/trace, and T2-STIR was negative; yet, 5/7 (71%) had pericarditis recurrence within 1-4 months of rilonacept suspension despite prophylactic colchicine (n=2). Conclusions: Continued clinical improvement during prolonged rilonacept treatment corresponded with improvement on CMR, including reduced pericardial thickness, resolution of pericardial edema on T2-STIR, and resolution of LGE. Negative/trace LGE at 18MDM while on treatment did not predict absence of pericarditis recurrence upon subsequent rilonacept suspension in this size-limited subgroup. Larger prospective studies examining CMR parameters in guiding RP treatment duration decisions and informing associated clinical outcomes are warranted.