We aimed to evaluate the (a) potential predictors of first biological disease-modifying anti-rheumatic drug (bDMARD) failure and (b) factors associated with failure of multiple therapies in psoriatic arthritis (PsA).
We enrolled consecutive PsA patients attending our unit and undergoing bDMARDs during 2004-2020. Disease characteristics, previous/ongoing treatments, comorbidities, and follow-up duration were recorded. Disease activity and functional and clinimetric scores were recorded at baseline and yearly and were compared between switchers and non-switchers, and within switchers according to the reasons for switching. Effectiveness was evaluated over time with descriptive statistics; multivariate Cox and logistic regression models were used to evaluate predictors of response and failure of multiple bDMARDs. Kaplan-Meier curves were used to assess differences in time-to-first bDMARD discontinuation. Infections and adverse events were recorded.
Two hundred sixty-four patients were included (117 (44.32%) females, mean age 56 years, mean PsA duration 15 years); 117 (44.32%) switched bDMARDs at least once. Switchers were mostly females, with higher Psoriasis Area and Severity Index and worse Health Assessment Questionnaire at baseline. Mean time-to-first bDMARD discontinuation was 72 months; 2-year and 5-year retention rates were 75% and 60%, respectively. Survival curves for anti-TNFα/anti-IL12/23/anti-IL17 were similar (p = 0.66). Main reasons for switching were inefficacy (67.52%) and adverse events (25.7%). Female sex was associated with a higher risk of first bDMARD discontinuation (HR = 2.39; 95% CI: 1.50-3.81) and failure of multiple bDMARDs (OR = 1.99; 95% CI: 1.07-3.69); initiating therapy before 2015 was protective (HR = 0.40; 95% CI: 0.22-0.73).
Survival rate was good for anti-TNFα and other bDMARDs. Female sex was a predictor of first bDMARD discontinuation, unlike mechanism of action, comorbidities, and BMI. Key Points • Drug survival in PsA patients was confirmed be greater for the first bDMARD administered. • In case of failure of the first bDMARD, switching/swapping proved a good treatment option, as reflected by a persistent satisfactory effectiveness with second-line bDMARDs and so subsequent switches. • Female sex may constitute a predisposing risk factor for flare and therapeutic switches. • Discontinuation or switching of biologics due to mechanism of action, comorbidities tolerability and BMI did not seem to impact first bDMARD withdrawal.