Six months predictors of DAPSA Remission With Guselkumab in Psoriatic Arthritis in a Multicenter Real-World Study

Real-world evidence on 12-month outcomes of guselkumab (GUS) in psoriatic arthritis (PsA) remains limited. This multicenter observational study aimed to identify predictors of 12-month DAPSA remission (DAPSA < 4) in patients with PsA treated with GUS. Secondary objectives were to assess remission rates and changes in disease activity at 6 and 12 months. We screened all patients with PsA initiating GUS across 26 Italian rheumatology centers. Data collected included demographics, disease activity measured by DAPSA, and psoriasis (PsO) extent classified as 0%, < 10%, 10-20%, or > 20% body surface area. A multivariable logistic regression model restricted to patients with an evaluable 6-month assessment was used to identify predictors of 12-month DAPSA remission. Covariates included age, sex, smoking status, body mass index, disease duration, number of prior advanced therapies, axial involvement, and 6-month articular and/or cutaneous response. Articular response was defined as DAPSA remission (DAPSA < 4), and cutaneous response as improvement by at least one PsO body surface area severity category. A two-sided p value < 0.05 was considered statistically significant. Of 278 initiators, 199 were evaluable at 6 months. At month 6, 18 patients had a combined articular and cutaneous response, 9 had an articular-only response, 74 had a cutaneous-only response, and 98 had no response. In intention-to-treat analyses, DAPSA remission was achieved by 12% at 6 months and 20% at 12 months; corresponding per-protocol rates were 16% and 30%. Median DAPSA decreased from 27.0 at baseline to 11.9 at 6 months and 8.6 at 12 months. In multivariable analysis, combined response (OR 64.6, 95% CI 5.7-731.2), joint-only response (OR 16.9, 95% CI 4.4-65.2), and skin-only response (OR 2.5, 95% CI 1.04-6.2) were associated with 12-month DAPSA remission. In routine practice, 6-month response status stratified the probability of 12-month DAPSA remission. Early articular remission and combined articular-cutaneous response showed the strongest associations, whereas skin-only improvement was a modest but statistically significant predictor and should not be interpreted as a strong determinant of later articular remission.