Sustained efficacy of the monoclonal anti-interleukin-1 beta antibody canakinumab in a 9-month trial in Schnitzler's syndrome
- Heleen D de Koning1,2,3,4,5,
- Joost Schalkwijk1,2,3,
- Johanna van der Ven-Jongekrijg3,4,
- Monique Stoffels3,4,5,
- Jos W M van der Meer3,4,5,
- Anna Simon3,4,5
- 1Department of Dermatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- 2Department of Dermatology, Nijmegen Centre for Molecular Life Sciences (NCMLS), Nijmegen, The Netherlands
- 3Department of Dermatology, Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Nijmegen, The Netherlands
- 4Department of General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- 5Department of General Internal Medicine, N4i Centre for Immunodeficiency and Autoinflammation, Nijmegen, The Netherlands
- Correspondence to Dr Heleen Dian de Koning, Department of Dermatology, Radboud University Nijmegen Medical Centre, PO Box 9101, Nijmegen 6500 HB, The Netherlands;
- Accepted 23 September 2012
- Published Online First 19 October 2012
Objectives Schnitzler's syndrome is a chronic disabling autoinflammatory disorder, characterised by chronic urticaria, paraproteinemia and systemic inflammation. The interleukin (IL) 1 receptor antagonist anakinra is a very effective treatment, but requires daily injection and blocks both IL-1α and IL-1β. Canakinumab is a selective human monoclonal anti-IL-1β antibody with a long half-life. We investigated the long-term efficacy and safety of canakinumab in Schnitzler's syndrome.
Methods In an open-label, single-treatment arm trial, eight patients with Schnitzler's syndrome received monthly injections with 150 mg canakinumab subcutaneously for 6 months, followed by a 3-month observation period. Primary outcome was complete or clinical remission at day 14. Secondary outcome measures included inflammatory markers, quality of life, time to relapse, safety and tolerability.
Results After stopping anakinra, patients developed moderate to severe clinical symptoms. Canakinumab induced complete or clinical remission at day 14 in all eight patients. Median C-reactive protein concentrations decreased from 169 mg/l at baseline to less than 10 mg/l on day 14 and remained low or undetectable. One patient discontinued participation on day 39 because of return of symptoms while all others remained in complete or clinical remission during the 6-month treatment period. Relapse after last canakinumab dose occurred within 3 months in four patients. For two patients, remission continued several months post-study. Five patients reported at least one adverse event, predominantly mild upper respiratory tract infections. One patient died in a traffic accident.
Conclusions In this 9-month study, monthly 150 mg canakinumab injection was an effective and well-tolerated treatment for Schnitzler's syndrome. Our data demonstrate that IL-1β plays a pivotal role in this disease.