Phase 2/3 Study of KPL-387 in Recurrent Pericarditis

Key Inclusion Criteria:

• Phase 2 and 3: Has a diagnosis of recurrent pericarditis

• Phase 2 and 3: Has signs and symptoms of recurrent pericarditis despite treatmentwith standard therapies

• Phase 2 and 3: Weighs at least 40 kg

• Phase 2: Taking NSAIDS and/or colchicine (in any combination)

• Phase 3: Taking NSAIDs and/or colchicine and/or glucocorticoids (in any combination)

Key Exclusion Criteria:

• Phase 2 and 3: Has a diagnosis of pericarditis that is secondary to specificprohibited etiologies.

• Phase 2 and 3: Has received an investigational drug during the 4 weeks beforescreening or is planning to receive an investigational drug at any time during thestudy.

• Phase 2 and 3: Has a history of active or untreated, latent tuberculosis (TB) priorto screening.

• Phase 2 and 3: Has a history of immunodeficiency.

• Phase 2 and 3: Has a history of immunosuppression, including positive humanimmunodeficiency virus (HIV) test results.

• Phase 2 and 3: Has chest x-ray at Screening or within 12 weeks before first studydrug administration, with evidence of malignancy, abnormality consistent with prioror active TB infection or active infection.

• Phase 2 and 3: Has a history of malignancy of any organ system within the past 5years before Screening (other than a successfully treated non metastatic cutaneoussquamous cell carcinoma or basal cell carcinoma and/or localized carcinoma in situof the cervix).

• Phase 2 and 3: Has a known or suspected current active infection or a history ofchronic or recurrent infectious disease (> 3 episodes in prior 12 months), includingbut not limited to, genitourinary infection, chest infection, sinusitis, orskin/soft tissue infection.

• Phase 2 and 3: Has had a serious infection, has been admitted to the hospital for aninfection, or has been treated for a documented infection requiring antibiotics fora documented infection within 2 weeks prior to first study drug administration.

• Phase 2 and 3: Has had an organ transplant (except corneal transplant performed morethan 3 months prior to first study drug administration).

• Phase 2 and 3: In the Investigator's opinion, has any other medical condition thatcould adversely affect the subject's participation or interfere with studyevaluations.