Background Adult Onset Still's Disease (AOSD) is a severe systemic autoinflammatory disease. Elevated interleukin (IL)-18 levels correlate with AOSD disease activity, suggesting a central role
Objectives To examine the safety and efficacy of IL-18 blockade in AOSD with the administration of Tadekinig alpha, a recombinant human IL-18 binding protein
Methods Patients (Pts) with AOSD according to Yamaguchi criteria were included if they had been previously treated for at least one month with corticosteroids (CS). The pts received either 80 mg (group 1) or 160 mg (group 2) Tadekinig alpha sc three times weekly for 12 weeks. Oral CS and/or conventional DMARDs were allowed at stable dose in combination with Tadekinig alpha. After 3 wks, group 1 pts qualified as non responders (CRP levels did not decrease by ≥50% from baseline values or absence of temperature normalization) could be up-dosed to 160 mg for an additional 12 weeks. The primary endpoint was safety and secondary endpoints included early signs of efficacy
Results 23 pts were included (10 and 13 in group 1 and group 2, respectively). 6 pts of group 1 were up-dosed to 160 mg. Baseline characteristics and safety and efficacy results are described in Table 1. Most adverse events (AEs) (47) were considered as mild or moderate. Three serious AEs (SAE) were reported including two that were considered not related to the study drug and one possibly related according to the investigator (toxic optic neuropathy). Four premature discontinuations were related to AEs, including 3 cases of injection site reactions and 1 SAE. Systemic response as defined by ≥70% decrease of serum C-reactive protein (CRP) or normalization of CRP and ferritin levels was obtained in 2/10 and 6/13 pts of groups 1 and 2, respectively in the ITT analysis, and in 2/9 and 6/9 pts of groups 1 and 2, respectively, in the PP analysis.
Conclusions IL-18 blockade by Tadekinig alpha has an acceptable safety profile and is efficacious, in particular at the 160 mg dosage, in patients with refractory AOSD
Disclosure of Interest C. Gabay Grant/research support from: AB2 Bio, Roche, Pfizer, Consultant for: AB2 Bio, Roche, Pfizer, MSD, BMS, AbbVie, Sanofi, B. Fautrel: None declared, J. Rech: None declared, F. Spertini: None declared, E. Feist: None declared, I. Koetter: None declared, E. Hachulla: None declared, J. Morel: None declared, T. Schaeverbeke: None declared, M. Hamidou: None declared, T. Martin: None declared, B. Hellmich: None declared, P. Lamprecht: None declared, H. Schultze-Koops: None declared, A. Sleight Employee of: Ab2 Bio, E. Schiffrin Employee of: Ab2 Bio