Objective. Cryopyrin-associated periodic syndromes (CAPS) are dominantly-inherited autoinflammatory diseases. The uncontrolled IL-1β overproduction observed in these patients is the rational basis to treat them with anti-IL-1 drugs. The objective of this study was to evaluate the efficacy and safety of treatment with the long-lasting fully humanised anti-IL-1β monoclonal antibody canakinumab in a Spanish cohort of patients with CAPS. Methods. Clinical and laboratory data of CAPS patients carrying a heterozygous germline NLRP3 mutation were obtained. The initial treatment scheme with canakinumab was 150 mg/8 weeks administered subcutaneously in adult patients and 2 mg/kg/8 weeks in paediatric patients.

Results. Eight unrelated patients were enrolled. Canakinumab was the first anti-IL-1 drug used in three of them; five were already receiving anakinra. The clinical response to the initial canakinumab scheme was positive in all patients, and was quickly observed in the first 24–72 hours. Four required increasing the frequency and/or dose of canakinumab. A limited or no efficacy in those symptoms related to consequence of the deforming arthropathy and neurosensorial deafness was observed. The adverse side effects were restricted to infectious complications in a small percentage of patients. The treatment was well tolerated by all patients, with no reactions at drug site injections. Conclusion. Canakinumab caused fast and sustained remissions in most clinical and biochemical manifestations in all enrolled patients, with a limited efficacy in the structural lesions. Dose adjustments seem to be necessary for children and/or for patients with the most severe CAPS phenotypes. Treatment was well tolerated with a low incidence of adverse effects.