An open-label continuation trial of tocilizumab for familial Mediterranean fever with colchicine ineffective or intolerance Study protocol for investigator-initiated, multicenter, open-label trial

Background: Colchicine is the first-line treatment for familial Mediterranean fever (FMF), but secondary amyloidosis resulting from persistent inflammation is a concern in patients with colchicine-resistant or colchicine-intolerant FMF. Although tocilizumab (TCZ), which is a recombinant, humanized, anti-human interleukin 6 receptor monoclonal antibody, has been reported to prevent FMF attacks, the long-term safety and efficacy of TCZ on individuals with colchicine-resistant or colchicine-intolerant FMF have not been evaluated. Methods/design: In this investigator-initiated, multicenter, open-label trial, the long-term safety of TCZ will be evaluated in patients participating in a placebo-controlled, randomized, double-blind, parallel-group trial on colchicine-resistant or colchicine-intolerant FMF. The study will be conducted in 9 centers in Japan. After the evaluation and examination for 24 weeks in the preceding study, this trial will be started promptly. The trial will be completed by the time the drug is approved for FMF treatment in Japan. The primary endpoint is the incidence of adverse events, and the secondary endpoints include the number of FMF attacks, number of occurrences of accompanying symptoms during attacks, serum C-reactive protein and amyloid A levels, general evaluation by a physician (100 mm visual analog scale [VAS]), general evaluation by a patient (100 mm VAS), and body temperature. Discussion: The study is expected to obtain evidence regarding the long-term safety of TCZ as a potential new therapeutic agent for patients with colchicine-resistant or colchicine-intolerant FMF.