Daily injections of anakinra, an interleukin-1-receptor antagonist, have been reported to control effectively the symptoms and signs of Schnitzler syndrome, a rare acquired autoinflammatory disorder, presenting in adulthood by intermittent fever, urticarial rash, and paraproteinemia, usually IgM. Canakinumab, a fully human interleukin-1β monoclonal antibody, approved for the cryoporin-associated periodic syndrome, may offer a practical advantage because its half-life of ∼28 days may allow less frequent dosing. The present trial was designed to test canakinumab in patients with Schnitzler syndrome.
A patient with Schnitzler syndrome was treated with canakinumab, 150 mg subcutaneously injection every 8 weeks for 6 consecutive months. Injections were resumed in case of a flare following discontinuation.
Canakinumab induced a swift and sustained clinical response, with disappearance of fever and arthralgias, near abolishment of fatigue and rash, and substantial reduction of C-reactive protein levels. Interruption of canakinumab after four 8-weekly injections led to a flare 10 weeks after the last administration, which was countered as soon as canakinumab injections were resumed. The patient remained in complete remission. Canakinumab was well tolerated. No injection site reactions, other adverse events, or laboratory abnormalities were observed.
Canakinumab has potential for the treatment of Schnitzler syndrome (ClinicalTrials.gov.number, NCT01245127).