Efficacy and safety of netakimab, anti-IL-17A monoclonal antibody, in patients with ankylosing spondylitis. Results of phase III international, multicenter, randomized double-blind clinical trial BCD-085-5/ASTERA

Netakimab (NTK) is a humanized monoclonal antibody targeting interleukin-17A.Objective. The main objective of BCD-085-5/ASTERA study was to prove superiority of NTK over placebo and assess its’ safety in patients with active AS.Subjects and methods. BCD-085-5/ASTERA was a double-blind, multicenter, randomized, placebo-controlled, phase III study, which included 228 adult patients with active AS, persisting despite active treatment with NSAIDs. AS was considered active at BASDAI score ≥ 4.0. Patients were blindly randomized (1:1) to receive subcutaneous injections of NTK (120 mg) or placebo at weeks 0, 1, 2 and then every other week up to week 14. Starting from week 16 all patients from NTK group and patients from placebo group not achieving ASAS20 were switched to open label 120 mg NTK s/c once every two weeks. The total duration of treatment with NTK was 3 years.Results. Higher proportion of patients had ASAS40 response at week 16 (primary endpoint) in NTK arm compared to placebo (40,4 vs 2,6%, р <0,0001, 95% CI [27,4%; 48,1%]). Spinal pain subsided and laboratory inflammation markers decreased within one week after the first NTK injection. NTK safety profile was comparable to that of placebo. The most common for NTK adverse events were neutropenia (7,0%) and ALT increase (6,1%).Conclusion. Subcutaneous NTK at 120 mg dose demonstrated superior efficacy vs placebo, with fast onset of response and favorable safety profile when used in patients with ankylosing spondylitis.