1. Male or female 18 years of age or older
2. A history of recurrent pericarditis* with stable disease and currently being treated with an IL-1 blocker, scheduled to be discontinued. Stable disease is defined as:

a. treatment with an IL-1 blocker for at least 12 months;

b. free of pericarditis recurrence for at least 6 months and this recurrence, if present, must have occurred in the setting of an interruption or tapering of an IL-1 blocker; and

c. treatment with an unchanged dose and regimen of on an IL-1 blocker for at least 3 months prior to randomization.

1. Pericarditis pain pain less than or equal to 2 on the 11-point Numerical Rating Scale (NRS) for at least the prior 7 days
2. C-Reactive Protein (CRP**) less than 1.0 mg/dL within the 7 days of screening prior to Day 1 (Visit 1)
3. Male patients with partners of childbearing potential who have had a vasectomy or who are willing to use double barrier contraception methods during the conduct of the trial and for 2 months after the last dose of trial therapy
4. Women of childbearing potential willing to use an acceptable method of contraception starting with trial drug administration and for a minimum of 2 months after trial completion. Otherwise, women must be postmenopausal (at least 1 year absence of vaginal bleeding or spotting and confirmed by follicle stimulating hormone [FSH] greater than or equal to 40 mIU/mL [or greater than or equal to 40 IU/L] if less than 2 years postmenopausal) or be surgically sterile.

1. Pericarditis recurrence(s) during IL-1 blocker treatment without interruption or tapering of the IL-1 blocker
2. Diagnosis of pericarditis that is secondary to specific prohibited etiologies, including tuberculosis (TB); neoplastic, purulent, or radiation etiologies; post-thoracic blunt trauma (e.g., motor vehicle accident); systemic autoimmune disease (e.g., systemic lupus erythematosus)
3. Primary diagnosis of myocarditis (diagnosis of myopericarditis is accepted)
4. Estimated glomerular filtration rate (eGFR) less than 30 mL/min at baseline
5. Elevated alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 5 times the upper limit of normal (ULN) or ALT or AST greater than 3x ULN plus bilirubin greater than 2x ULN
6. Sepsis, defined as documented bacteremia at baseline or other untreated or uncontrolled bacterial infection*
7. Prior history of sustained ventricular arrhythmia(s)
8. History of diagnosed long QT syndrome
9. QTc interval greater than 500 msec at baseline
10. Showing suicidal tendency, as defined by answering "yes" to question 4 or 5 of the Columbia Suicide Severity Rating Scale (C-SSRS), administered at baseline
11. Currently participating in any research trial involving investigational drugs or devices
12. Inability or unwillingness to give informed consent
13. Ongoing drug or alcohol abuse in the opinion of the investigator
14. On any cannabinoid during the past month and unwilling to stay abstinent from all cannabis products for the duration of the trial
15. Pregnant or breastfeeding
16. Current diagnosis of cancer, with the exception of non-melanoma skin cancer
17. Any factor, which would make it unlikely that the patient can comply with the trial procedures
18. Moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment
19. Has received systemic immunomodulatory agents prior to randomization:

1. Methotrexate (within 2 weeks)
2. Azathioprine (within 24 weeks)
3. Cyclosporine (within 24 weeks)
4. Intravenous immune globulin (IVIG) (within 8 weeks)
5. Corticosteroids (within 4 weeks).