Background: The purpose of this trial was to evaluate the effectiveness and safety of the IL-6 receptor antibody Tocilizumab (TCZ) in the treatment of Familial Mediterranean Fever (FMF). Methods: This was a randomized, double-blinded, placebo-controlled phase II trial in adult patients with active FMF and an inadequate response or intolerance to colchicine (crFMF). The physician’s global assessment of disease activity (PGA), based on a five-point scale for six symptoms, was used as a clinical score, which had to be >2 at screening, together with elevated c-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) and serum amyloid A (SAA) levels, to be eligible for inclusion. Patients were randomized 1:1 to either receive monthly TCZ or a placebo over a period of 24 weeks. The primary endpoint was the number of patients achieving an adequate response to treatment at week 16, defined as a PGA of ≤2 and normalized ESR or CRP and normalized SAA. Results: We randomized 25 patients with a median age of 31 years. At week 16, an adequate treatment response was achieved by two patients in the TCZ and none of the patients in the placebo arm (p = 0.089). SAA levels normalized with TCZ, but not with the placebo (p = 0.015). Conclusion: In this first randomized, placebo-controlled study in patients with active crFMF, more patients in the TCZ arm experienced a response to treatment in comparison to those receiving the placebo. As the prevention of amyloidosis is a major treatment goal in FMF, the normalization of SAA in TCZ-treated patients is essential. These findings have to be confirmed in a larger trial.
Keywords: Familial Mediterranean Fever; colchicine resistant; interleukin 6; tocilizumab; treatment.