RHAPSODY Clinical Trial Design1,2
Trial design: A Phase 3, multicenter, double-blind, event-driven, RW trial of ARCALYST in recurrent pericarditis patients with acute symptoms of at least a second recurrence despite treatment with traditional therapies (NSAIDs, colchicine, or corticosteroids, alone or in combination).
Trial began with a 4-week screening period to establish trial eligibility and was followed by 3 periods:
12-week RI
Initiation of ARCALYST and transition to monotherapy
- 1-week stabilization
- 9 weeks weaning from background therapies
- 2 weeks ARCALYST monotherapy
Event-driven,
double-blind RW
Treatment with ARCALYST or placebo*
- 1:1 randomization to weekly ARCALYST or placebo
- Continued until the prespecified number of primary efficacy end point events
- 18 months after the most recent pericarditis event (qualifying or RW period), a decision was made for each patient to†:
- Continue open-label ARCALYST
- Suspend treatment for observation (ARCALYST rescue for recurrence allowed)
- Exit the study
*For patients who met the prespecified clinical response criteria for ARCALYST. †Based on clinical status and at investigator discretion.
Inclusion and Exclusion Criteria at Screening1‡
Key inclusion criteria
- Male or female 12 years of age or older
- Diagnosed with recurrent pericarditis
- Presenting with at least a second recurrence of pericarditis
- If using NSAIDs, colchicine, corticosteroids, or any combination thereof, doses remained stable for 3 days prior to first drug administration
‡This list is not all-inclusive.
Key exclusion criteria
- Diagnosis of pericarditis secondary to specific prohibited etiologies:
- Tuberculosis
- Neoplastic, purulent, or radiation etiologies
- Post-thoracic blunt trauma (eg, motor vehicle accident)
- Myocarditis
- Systemic autoimmune diseases (with exception of Still’s disease)
- Pregnant, breastfeeding, planning a pregnancy, or planning on fathering a child
- History of immunosuppression
RHAPSODY Trial Population
Select characteristics of clinical trial participants1,3
- Total population: 86
- Mean patient age: 45 years (range 13-78)
- 57% female
- Diagnosis of “idiopathic” pericarditis: 85% (n=73)
- Remainder: post-pericardiotomy syndrome and Dressler syndrome
- Medications used at baseline (alone or in combination)§:
- NSAIDs: n=58
- Colchicine: n=69
- Corticosteroids: n=41
- Mean duration of disease: 2.4 years
- Mean pericarditis events per year: 4.4
- Including the qualifying pericarditis event§
- Mean qualifying NRS pain score: 6.2
- Mean qualifying CRP level: 6.2 mg/dL
§Qualifying pericarditis event: 0-10 point NRS ≥4 and CRP ≥1 mg/dL.
Patient Disposition2
Initiation of ARCALYST and transition to monotherapy (N=86)
Treatment with ARCALYST or placebo (N=61)
Eligible patients were offered open-label ARCALYST for up to 24 additional months
99% (74 of 75) chose to enter the LTE
- 59 directly from the RW period and 15 from the RI period after enrollment in the RW period closed
52 patients reached the 18-month decision milestone‖
- 33 continued open-label ARCALYST
- 8 suspended treatment for observation
- 11 exited the study
‖22 patients discontinued the LTE prior to reaching the 18-month decision milestone.
- 18 US participants transitioning to commercial ARCALYST at the time of US approval
- 4 (US/ex-US) participants due to lost to follow-up (1), AE (2), and withdrawal of consent (1)
References: 1. Klein AL, Imazio M, Cremer P, et al. Phase 3 trial of interleukin-1 trap rilonacept in recurrent pericarditis. N Engl J Med. 2021;384(1):31-41. 2. Imazio M, Klein AL, Brucato A, et al. Sustained Pericarditis Recurrence Risk Reduction With Long-Term Rilonacept. J Am Heart Assoc. 2024;13(6):e032516. doi:10.1161/JAHA.123.032516. 3. ARCALYST. Package insert. Kiniksa Pharmaceuticals.