%0 Journal Article %A A. Deodhar %A D.D. Gladman %A I.B. McInnes %A S. Spindeldreher %A R. Martin %A L. Pricop %A B. Porter %A J. Safi Jr %A A. Shete %A G. Bruin %T Secukinumab immunogenicity over 52 weeks in patients with psoriatic arthritis and ankylosing spondylitis %D 2019 %R 10.3899/jrheum.190116 %J The Journal of Rheumatology %P jrheum.190116 %X Objective Secukinumab, a fully human anti–interleukin-17A monoclonal antibody, is efficacious for the treatment of psoriatic arthritis (PsA) and ankylosing spondylitis (AS). This study examined the immunogenicity of secukinumab in patients with PsA and AS exposed to secukinumab for up to 52 weeks. Methods Antibody bridging assays were used to assess the immunogenicity of secukinumab in patients with PsA (FUTURE 1–3 studies, and AS (MEASURE 1–4 studies). Evaluations were at Baseline (BL) and at Weeks 16 (AS only), 24 and 52. Treatment-emergent anti-drug antibodies (TE-ADA) were defined as a positive ADA signal in ≥ 1 post-treatment sample in patients negative at baseline. Positive samples were analyzed for drug-neutralizing potential and impact of TE-ADA on secukinumab pharmacokinetics, immunogenicity-related adverse events, and on efficacy through Week 52 was assessed. Results Of 1414 treated PsA and 1164 treated AS patients with samples available for immunogenicity evaluation, five (0.35%) and eight (0.69%), respectively, developed TE-ADA. All but one PsA patient were biologic naïve; two of the five PsA and one of the eight AS patients received concomitant methotrexate, and two of the eight AS patients received concomitant sulfasalazine. Associations between TE-ADA and secukinumab dose, frequency or administration mode were not observed. Other than one PsA patient, all TE-ADA were non-neutralizing. No TE-ADA were associated with any adverse events. All TE-ADA were associated with normal secukinumab pharmacokinetics and none were associated with loss of secukinumab efficacy. Conclusion Secukinumab treatment was associated with a low (<1%) incidence of immunogenicity in PsA and AS patients. %U https://www.jrheum.org/content/jrheum/early/2019/06/11/jrheum.190116.full.pdf