Recurrent Pericarditis

The primary objective of this study is to characterize the efficacy and safety of dosing regimens used to transition from prior pericarditis therapies to KPL-387 monotherapy in participants with well-controlled recurrent pericarditis on standard therapies.

This study is being done to demonstrate whether KPL-387 is an effective and safe treatment for recurrent pericarditis.

Multi-center, randomized, double-blind, placebo-controlled, phase-3 Trial. Patients with a history of recurrent pericarditis who are being treated with an IL-1 blocker for at least 12 months, scheduled to be discontinued, will be approached for potential trial participation. Double-blind treatment will be initiated 10 - 16 days prior to the last scheduled dose of the IL-1 blocker and continued for 24 weeks. The objective is to assess whether patients remain free of pericarditis recurrence while receiving CardiolRx.

This is a study to understand if taking VTX2735 is safe and effective in participants diagnosed with Recurrent Pericarditis (RP). Cohort A will include approximately 10 participants and will consist of the following: * A 30-day Screening Period (to see if a participant qualifies for the study) * A 6-week Open Label Treatment Period - participant receives VTX2735 Dose A * A 7-week Extension Treatment Period (if a participant meets criteria for extension treatment) - participant receives VTX2735 Dose A * An 11-week Once Daily Treatment Period (if a participant meets criteria for this treatment period) - participant receives VTX2735 Dose B * A 14-day Follow-Up Period Cohort B will include approximately 20 participants and will consist of the following: * A 30-day Screening Period (to see if a participant qualifies for the study) * A 6-week Open Label Treatment Period - participant receives VTX2735 Dose B or C * An 18-week Extension Treatment Period (if a participant meets criteria for extension treatment) - participant receives VTX2735 Dose B or C * A 14-day Follow-Up Period Cohort C will include approximately 20 participants and will consist of the following: * A 30-day Screening Period (to see if a participant qualifies for the study) * A 6-week Open Label Treatment Period - participant receives VTX2735 Dose D or E, and B * An 18-week Extension Treatment Period (if a participant meets criteria for extension treatment) - participant receives VTX2735 Dose B * A 14-day Follow-Up Period