Rilonacept for Treatment of Cryopyrin-Associated Periodic Syndromes (CAPS)

Inclusion Criteria: * Double-blind phases: adults age 18 and above; Open-label extension: Adults and children aged 7 years and older. * Was diagnosed with Familial Cold Auto-inflammatory Syndrome (FCAS) or Muckle-Wells Syndrome (MWS) based upon clinical signs and symptoms * Had documented mutation in NLRP-3 (Cold Induced Autoinflammatory Syndrome-1 or CIAS1) in subject or relative, and willingness to have a confirmatory genetic (Deoxyribonucleic acid or DNA) test (cheek swab). * Was able to understand and comply with study procedures and was able to provide informed consent * If female, was not currently pregnant and was willing to use contraception during the study Exclusion Criteria: * Had evidence of untreated tuberculosis or other conditions/therapies that made the subject inappropriate for this study.