Recurrent pericarditis is a rare, probable autoinflammatory disorder mediated by interleukin-1 (IL-1); and is often refractory to glucocorticoids and colchicine. A novel trial of IV rilonacept, an IL-1 α and IL-1β cytokine trap, resulted in rapid resolution of recurrent pericarditis and to a significantly lower risk of recurrence compared to placebo.
RHAPSODY was a phase 3 multicenter, double-blind, event-driven, randomized-withdrawal trial of rilonacept in 86 patients with recurrent pericarditis. After a 12-week run-in period of rilonacept, those who responded either continued rilonacept (RIL) monotherapy or were withdrawn to receive placebo (PBO).
All patients had recurrent pericarditis and an elevated CRP level. During the run-in period, the median time to resolution of pain was 5 days, and the median time to normalization of the CRP level was 7 days.
A total of 61 patients were responders and were further randomized to PBO or RIL.
During the randomized-withdrawal period, only 2 of 30 patients (7%) in the rilonacept group had a pericarditis recurrence, as compared with 23 of 31 patients (74%) in the placebo group. The median time to the first recurrence in the placebo group was 8.6 weeks.
The most common adverse events with rilonacept were injection-site reactions and upper respiratory tract infections.
IL-1 inhibitiion with IV riloacept appears to be highly effective in those with recurrent pericarditis.