Safety and Tolerability of Rilonacept in Muckle-Wells Syndrome (MWS) or Schnitzler Syndrome (SchS)

This is a single-center open label study of the IL-1 transfusion protein rilonacept in subjects with Muckle-Wells syndrome (MWS), or Schnitzler syndrome (SchS) in Germany. Prospective subjects will be recruited from a patient population previously characterized in an observational study, and from referrals within the German CAPS community; SchS subjects will be recruited through the Charité Patient pool. The Baseline phase will begin with the Screening visit (day -21 = Visit 1) and continue for three weeks; DHAFs (Daily Health Assessment Forms) will be collected from all subjects from Day - 21 to Day 0. DHAF information including MWAS (Muckle-Wells Activity Score), or SCHAS (Schnitzler Activity Score) values from this period will be used for the baseline phase evaluation. Inclusion to receive rilonacept will occur on day 0 (= Visit 2). On day 0 eligible subjects will receive a loading dose of two subcutaneous (S.C.) injections of rilonacept for a total of 320 mg. Subsequent study drug injections of rilonacept 160 mg will be administered once a week for four weeks. After subjects complete this initial 4-week treatment phase, they will be eligible to receive rilonacept 160 mg once weekly for 48 weeks during the extended treatment phase. DHAFs will be used to assess symptoms throughout the study. Overall a max. of 12 subjects with either MWS or SchS will be enrolled.