Background: Switching between therapies is a recommended strategy for rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients who experience treatment failure; moreover, data on switching due to primary non-response and subsequent failures are limited.
Objectives: To obtain information from clinical practice regarding failures due to primary non-response in patients on biologic and target synthetic disease-modifying antirheumatic drugs (ts/bDMARDs), assessing the incidence rate (IR) of switching due to primary non-response and risk of subsequent treatment failure by cycling compared to swapping.
Design: A longitudinal retrospective study, spanning from 2007 to 2022, was conducted on patients with RA or PsA treated with ts/bDMARDs at an outpatient rheumatology clinic.
Methods: The main outcomes were as follows: (1) ts/bDMARD failure due to primary non-response and (2) subsequent discontinuation of prescribed ts/bDMARD due to lack of efficacy. The independent variable was switching between classes compared to switching within class. As covariates, clinical, sociodemographic, clinical, and treatments were considered. To estimate ts/bDMARDs switching rates, survival techniques were used, expressing the IR per 100 patients * year with their 95% confidence interval. Cox multivariate regression analyses were run to assess the role of switching between/within class in the subsequent treatment failure.
Results: In total, 327 patients were included. Of these, 50 patients in 77 treatment courses developed primary non-response with an IR of 4.25 (3.4-5.3). The IR was quite similar between RA and PsA, higher in women, and in those who started ts/bDMARDs after 2018. In those with primary non-response, there were 42 subsequent treatment failures with an IR of 26.38 (19.49-35.69). The multivariate model showed that cycling increased the risk of subsequent failure compared to swapping (hazard ratio: 2 (1.1-3.77), p = 0.03).
Conclusion: This study provides support to consider swapping a better alternative rather than cycling after primary non-response.
Keywords: biologic and target synthetic disease-modifying antirheumatic drugs; primary non-response; psoriatic arthritis; rheumatoid arthritis; switching.
Initial lack of efficacy for biologic therapies in rheumatoid arthritis or psoriatic arthritis in daily clinical practice.
Introduction: The studied drugs are biological therapies that are arthritis-modifying drugs designed early in the last decade to prevent or reduce inflammation caused by the disease. This study focuses on initial lack of efficacy, in patients with rheumatoid arthritis or psoriatic arthritis who are treated with biologic therapies. We wanted to know how often these treatments fail to work right from the start and how it impacts future treatment choices in real-life practice.
Methods: We included patients from 2007 to 2022 in which their consultant rheumatologist had decided to commence them on biologic therapy. We studied the changes due to initial lack of efficacy, we also included sociodemographic, clinical and treatments information.
Results: The results showed that, of the 327 patients, 50 experienced primary initial lack of efficacy. This means about 4 out of every 100 patients had this treatment failure due, with a higher rate seen in women and those starting treatment after 2018. Among those who didn’t respond to their initial treatment, there were 42 further treatment failures, with changes within the same drug class (cycling) more often than changes between classes (swapping).
Conclusion: This study provides support to consider swapping (changes between drug classes) a better alternative rather than cycling (changes within the same drug class) after initial lack of efficacy. We consider these finding useful for the management of patients. Implementation of more effective strategies may change the disease course.
© The Author(s), 2025.