Inclusion Criteria:

• Participants are male or female ≥ 18 years up to ≤ 75 years of age.
• Capable of giving signed informed consent and able to comply with the protocol
• Previously had an index (first) episode of pericarditis which met the criteria for an acute pericarditis event
• Ongoing symptomatic episode of pericarditis, or may have an episode of recurrent pericarditis in the next 4 weeks.
• CRP by local laboratory assessment prior to first dose of study treatment (participants with CRP ≤ 10 mg/L must be receiving corticosteroid treatment for RP and have evidence of pericardial inflammation)
• Pericarditis pain score ≥ 4 based on the 11-point NRS.
• Stable doses of NSAIDs, colchicine, and/or oral corticosteroids (if receiving these treatments)

Exclusion Criteria:

• Current or prior diagnosis of pericarditis that is secondary to specific prohibited causes, including but not limited to tuberculosis, blunt trauma, tumor, myocarditis, or systemic autoimmune diseases.
• History of clinically significant immunosuppressive disorder, autoimmune/autoinflammatory disorder, or primary or secondary immunodeficiency.
• Clinically important history of a medical disorder that would compromise safety or data quality, per the Investigator's judgment.