Response to Letter by Wallace et al.

We thank Wallace et al. for their interest in our paper, ‘Drug survival of biologics in psoriasis: An Australian multicentre retrospective study’. They raise important considerations regarding factors that may influence biologic switching, which warrant further exploration. The authors highlight the potential role of pharmaceutical promotion in influencing prescribing habits. In psoriasis, biologics are not therapeutically interchangeable. Differences in efficacy, speed of onset, safety profiles, and suitability for co-existing conditions such as psoriatic arthritis or inflammatory bowel disease are well established. Isolating the potential effect of pharmaceutical promotion from clinicians' preferences for agents with demonstrated clinical advantages is inherently challenging. In therapeutic areas where agents are more closely matched in efficacy and safety, the role of promotional influence may indeed be more pronounced and warrants targeted investigation. More broadly, it is essential to recognise that dermatologists operate within a complex, evolving therapeutic landscape. A dynamic interplay of clinical evidence, patient-specific factors, guideline recommendations, and long-term treatment goals shapes prescribing decisions. In routine practice, prescribing choices are often made in partnership with patients, balancing disease control, safety considerations, lifestyle implications, and individual treatment preferences. The authors raise the question of whether dermatologists have a societal responsibility to consider cost when switching between biologic agents. In Australia, the cost of biologic agents to the Pharmaceutical Benefits Scheme (PBS) is not publicly disclosed. Patients typically encounter only the standard PBS co-payment, and clinicians may refer to indicative pricing available through the PBS website—figures that often do not reflect confidential, government-negotiated prices. Without cost transparency, it is difficult for clinicians to make informed, cost-based prescribing decisions. Furthermore, while healthcare resource stewardship is important, clinicians must also prioritise optimising patient outcomes. The suggestion that clinicians should hesitate to switch in the setting of partial clearance presumes that further improvement offers limited benefit. However, multiple studies show that striving for complete or near-complete skin clearance is associated with substantial improvements in quality of life [1-3]. Importantly, Song et al. recently showed that even among patients with excellent clinical response to biologics (median PASI 0.4), over half still reported a negative impact on quality of life [2]. Achieving PASI-100 was independently associated with a significantly higher likelihood of DLQI 0/1, while prior biologic treatment failure was negatively associated with good patient-reported outcomes [2]. This underscores that minimal residual skin lesions and prior treatment experiences can meaningfully affect patient wellbeing, even in the setting of near-clear skin. Psoriasis impacts more than just the skin. It significantly affects mental health, self-esteem, and daily functioning [4]. These challenges have real-world consequences—they limit a person's ability to work, maintain economic independence, and participate fully in society. In one large U.S. survey, 92% of psoriasis patients who were unemployed identified their condition as the primary reason for being out of work [5]. These findings are supported by a systematic review estimating that indirect costs from lost productivity, absenteeism, and presenteeism account for up to 40% of the total economic burden of psoriasis, underscoring how the toll of this disease extends far beyond medication budgets [6]. Therefore, while medication costs are important, the broader cost of under-treatment, including lost productivity and diminished quality of life, must also be considered when evaluating treatment value. Framing prescribing decisions around cost-minimisation risks undervaluing the very real burden carried by patients who remain partially controlled but still deeply impacted. In practice, decisions to switch or escalate therapy are not taken lightly. They reflect a commitment to aligning treatment goals with patient needs and restoring meaningful quality of life. The authors note that our study did not discuss the potential role of cost or pharmaceutical promotion in shaping prescribing decisions. While these are undoubtedly important systemic factors, we chose to focus the discussion on directly observable clinical variables, rather than extrapolating beyond the limits of our dataset. At the time, we felt it was more appropriate to avoid speculation around factors we could not reliably assess within the study design. That said, this does highlight an opportunity. Future research could build on our findings by incorporating prescriber interviews, policy analysis, or cost-modelling to explore how these broader influences intersect with real-world prescribing behaviour. Editor’s Note: Regarding the recent correspondence letter from Wallace and Muir (ref to AJD.14446) there was an error in the editorial process whereby a revision was made and accepted following feedback from the original authors. This has resulted in discrepancy with the published reply from the original authors (ref to AJD.14483). We would like to thank the authors for highlighting this error. Wallace and Muir have declined an invitation to publish their original commentary, however a further response has been made by the original authors (ref to AJD.14568, if not published as part of that paper). Pablo Fernández-Peñas has served on advisory boards for AbbVie, Amgen, Boehringer Ingelheim, Eli Lilly, Johnson & Johnson, L’Oreal, LEO Pharma, Merck, Merck Sharp & Dohme, Novartis, Pfizer, and UCB; has given educational lectures for AbbVie, Amgen, Eli Lilly, Galderma, Johnson & Johnson, L’Oreal, LEO Pharma, Merck, Merck Sharp & Dohme, Novartis, Pfizer, Pierre Fabre, UCB Pharma and Zuellig Pharma; has received research funding from Pfizer; has conducted clinical trials for AbbVie, Akesobio, Alumis, Amgen, Apogee, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, CellDex, CSL, Chugai, Eisai, Eli Lilly, Galderma, Incyte, Johnson & Johnson, Jiangsu Hengrui, KoBioLabs, Merck, Merck Sharp & Dohme, miRagen, Moderna, Nektar, Novartis, OncoSec, Pfizer, Regeneron, Sanofi, UCB Pharma. The authors have nothing to report.