Rilonacept for Treatment of Familial Mediterranean Fever (FMF)

Inclusion Criteria: * Subject has a definitive diagnosis of FMF as by the Tel-Hashomer clinical criteria (long version of criteria) with at least one mutation on one of the MEFV gene alleles. However, subjects with an isolated heterozygous mutation of exon 2 of the MEFV gene (including E148Q) will not be eligible. * Subject must have an estimated mean of at least one acute FMF attack per month before and during the month of screening. * Subject is at least four years of age (with no upper limit of age). * Subjects must have received an adequate trial of colchicine defined as treatment of at least 1.5 mg/d for at least 3 months if ≥6 years old or 1.2 mg/d if less than 6 years, or an inability to tolerate colchicine due to adverse effects in a dose that controls acute attacks in the frequency of less than one attack per month. * If subject is being treated with anakinra at the time of consent, washout must be done (about 3 days). Subject must experience 2 attacks before randomization visit can occur. * If subject has been treated previously with anti-TNF drugs, appropriate washout must be done. Etanercept must be discontinued for 4 weeks prior to randomization; Adalimumab and Infliximab must be discontinued for 8 weeks prior to randomization. * If subject is a female of childbearing potential, she must agree to use adequate contraception (adequate contraception can include abstinence) for the duration of the trial and 3 months after and must have a negative serum or urine preg…