# Dose Tapering of Advanced Therapies in Psoriatic Arthritis: Clinical Predictors and Outcomes in a Biosimilar-Dominant Real-Life Cohort

## TL;DR

This study examines how often doctors reduce medication doses for psoriatic arthritis patients who are doing well, especially those using biosimilar treatments.

## Contribution

The study identifies clinical predictors for dose tapering in a real-life cohort dominated by TNFα inhibitor biosimilars.

## Key findings

- 24.6% of patients achieved sustained dose reduction, mostly in the TNF inhibitor group.
- Male sex, non-smoking status, and first-line TNFi use were independently associated with dose tapering.
- 8% of patients on TNFα inhibitor biosimilars experienced loss of therapeutic response after dose reduction.

## Abstract

Background: Dose tapering in patients with psoriatic arthritis (PsA) who achieve sustained treatment targets is a common but underexplored strategy, particularly in those receiving TNFα inhibitor biosimilars (TNFibs). This study aimed to assess the prevalence of dose optimization and identify factors associated with its implementation in clinical practice. Methods: We systematically selected 130 PsA patients with sustained treatment response from a database of individuals treated with advanced therapies. We evaluated the prevalence of dose optimization (defined as sustained dose reduction) and explored associated factors using multivariate logistic regression models. Results: Of the 130 patients, 95 were receiving TNF inhibitors and 35 other advanced therapies. Among those on TNFis, 88 (93%) were treated with TNFibs. A total of 32 patients (24.6%) were undergoing dose optimization, including 30 from the TNFi group (p = 0.002). We found that 7 of the 88 patients on TNFibs (8%) experienced loss of therapeutic response during follow-up. One in three patients on TNFis underwent dose tapering. Factors independently associated with dose reduction included no history of tobacco exposure [OR 3.98, 95%CI: 1.3–14.2; p = 0.021], male sex [OR 3.26, 95%CI: 1.26–9.04; p = 0.018] and use of TNFis as first-line advanced therapy [OR 4.8, 95%CI: 1.7–16.7; p = 0.003]. Conclusions: Approximately one in four PsA patients who achieve sustained treatment targets undergo dose optimization, most commonly with TNFibs. This strategy appears to be more feasible in male patients, non-smokers and those treated with TNFis as a first-line option.