Background: Impact of recurrent pericarditis (RP) on patient health-related quality of life (HRQoL) was evaluated through qualitative patient interviews and as an exploratory endpoint in a Phase 2 trial evaluating the efficacy and safety of rilonacept (IL-1α/IL-1β blocker) to treat RP.Methods: Qualitative interviews were conducted with ten adults with RP to understand symptoms and HRQoL impacts, and the 10-item Patient-Reported Outcomes Measurement Information System Global Health (PROMIS Global) v1.2 was evaluated to determine questionnaire coverage of patient experience. The Phase 2 trial enrolled participants with active symptomatic RP (A-RP, n=16) and corticosteroid-dependent participants with no active recurrence at baseline (CSD-RP, n=9). All participants received rilonacept weekly for 6 weeks during a base treatment period (TP) plus an optional 18-week extension period (EP). Concomitant medications, including corticosteroids (CS), were tapered, if possible, during EP. HRQoL was assessed using the PROMIS Global, and patient-reported pain and blood levels of c-reactive protein (CRP) were also collected at Baseline and follow-up periods. Results: Information from qualitative interviews demonstrated that PROMIS GH concepts are relevant to adults with RP. From the Phase 2 trial, both participant groups showed impacted HRQoL at Baseline [mean PROMIS Global Physical Health (GPH) and Global Mental Health (GMH), were lower than population norm average]. In A-RP, GPH/MPH improved by end of base TP and were sustained through EP (similar trends were observed for pain and CRP). Similarly, in CSD-RP, GPH/MPH improved by end of TP and further improved at EP, during CS tapering or discontinuation, without disease recurrence (low pain scores and CRP levels continued during the TP and EP). Conclusion: This is the first study demonstrating impaired HRQoL in RP. Rilonacept treatment was associated with HRQoL improvements using PROMIS GH scores. Maintained/improved HRQoL during tapering/withdrawal of CS without recurrence suggests that rilonacept may provide an alternative to corticosteroids. Trial Registration: ClinicalTrials.Gov; NCT03980522; 5 June 2019, retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT03980522