Objective: Guselkumab, a human monoclonal antibody specific to interleukin-23p19, demonstrated efficacy and safety versus placebo through Week24 of the Phase-3 DISCOVER-2 trial in biologic-naïve psoriatic arthritis (PsA) patients. Here we report 1-year DISCOVER-2 findings.
Methods: Adults with active PsA (≥5 swollen+≥5 tender joints; C-reactive protein ≥0.6mg/dL) despite standard nonbiologic treatment were randomized to receive subcutaneous injections of guselkumab 100mg every-4-weeks (Q4W); guselkumab 100mg at Week0, Week4, Q8W; or placebo with crossover to guselkumab 100mg Q4W at Week24. We primarily evaluated clinical efficacy through Week52 by imputing missing data (nonresponse for categorical endpoints; no change/using multiple imputation for continuous endpoints). Observed radiographic scores and adverse events (AEs) were summarized.
Results: Of 739 randomized, treated patients, 93% completed Week52. Proportions of patients achieving ≥20% improvement from baseline in ACR criteria (ACR20) were maintained post-Week24, reaching 71% (173/245) and 75% (185/248) for Q4W- and Q8W- randomized patients, respectively, by Week52. The proportions of patients achieving ACR50/ACR70 and skin responses, minimal or very low disease activity, and dactylitis or enthesitis resolution were also maintained through Week52. Further, low levels of radiographic progression, along with improvements in physical function and health-related quality-of-life, were sustained through Week52 with continued guselkumab. Few patients experienced serious infections through Week52, with no evidence of a dosing regimen response or increase from Week0-24 (4/493 [0.8%]) to Week24-52 (3/493 [0.6%]) among guselkumab-randomized patients. No patient developed an opportunistic infection or died.
Conclusion: In biologic-naïve PsA patients, guselkumab provided sustained improvements across diverse manifestations and maintained a favorable benefit-risk profile through Week52.