Long-term efficacy and safety of colchicine and anti-IL-1 blockers in FMF: results from the Eurofever multicenter observational study.

INTRODUCTION

The majority of currently available data on familial Mediterranean fever (FMF) come from retrospective national or international studies.

METHODS

An observational study collected data on the Eurofever international FMF cohort. Patients fulfilling genetic and clinical Eurofever criteria were considered as FMF+. Patients not fulfilling clinical and/or genetic (one VUS or benign variants or negative for MEFV variants) criteria were considered as FMF-. Data on compliance to treatment and quality of life were also recorded.

RESULTS

Since November 2024, 876 FMF patients (466 M, 410 F) were enrolled, with a mean follow-up of 2.9 ± 3.1 years. 730 (84 %) patients were classified as FMF+, 146 (16 %) as FMF-, with significant differences in the prevalence of clinical manifestations and treatment response between the two groups. At the last follow-up, 433 patients (50.6 %) still had some disease activity. At the last follow-up 749 (85.5 %) patients received colchicine with a relative under dosage of the drug. Anti-IL-1 treatment was reported in 133 patients (15.2 %), mostly canakinumab (117, 13.4 %). Treatment compliance was generally satisfactory, and adverse events were generally mild.

CONCLUSIONS

Patients with an FMF-like phenotype who lack genetic confirmation display significant differences in clinical features and duration of attacks and show a less response to treatment during their disease course in respect, and thus, should be considered as FMF-mimics and investigated for other causes. Longitudinal data provides a more detailed comprehension of the long-term burden of FMF and the impact of treatment on disease activity and patients' quality of life.