Bridging theory and practice in model‐informed precision dosing of medication in inflammatory skin diseases

Rising healthcare costs and the carbon footprint associated with medication underscore the need for more appropriate prescribing practices, including personalized dosing strategies that optimize biologic use and reduce unnecessary drug exposure. Against this background, Eylenbosch et al. provide a timely and comprehensive overview of personalized dosing approaches in dermatology. ¹ In their JEADV review, the authors clearly describe the principles, opportunities and limitations of therapeutic drug monitoring (TDM) and model‐informed precision dosing (MIPD) in inflammatory skin diseases. Model‐informed precision dosing (MIPD) represents a methodological improvement compared to traditional TDM strategies. Whereas traditional TDM is largely reactive and based on static therapeutic ranges, MIPD integrates pharmacokinetic/pharmacodynamic models with individual patient data, often using Bayesian forecasting, to individualize drug dosing and predict drug exposure. By incorporating patient‐specific covariates such as body weight, albumin, immunogenicity and comedication, MIPD aims to improve achieving dosages that fall within established therapeutic ranges. Empirical dosing strategies are also popular and do not require information on drug concentrations; dosages are adapted based on observed disease activity. Next to simplicity, empirical dosing strategies may have an additional benefit: it may identify those individuals who require lower dosages than the therapeutic targets that are being pursued in TDM‐based dosing strategies. In TDM‐based dosing strategies, those patients are regarded as being at risk for future disease exacerbations and dosages are preventively increased or switched to other medication, but more evidence is needed whether this hypothesis holds.

Importantly, the added value of TDM‐based strategies should be evaluated using an appropriate methodological framework. TDM is best viewed as a diagnostic intervention, and its clinical utility should therefore be tested against empirical dose adjustment strategies in a randomized controlled trial. ² An important outcome in this context that should not be overlooked is cost‐effectiveness. Investigating this before implementation will prevent the adoption of strategies that will add complexity and costs without clear additional benefit over empirically guided strategies. The BeNeBio study and the PLAN‐psoriasis feasibility study will provide important knowledge for psoriasis as the first combines empirical dose adjustments in Il17 inhibitors and IL23 inhibitors, and drug levels are evaluated afterwards, and the second compares a TDM‐guided strategy with patient‐led (empirical) on demand therapy with risankizumab in a randomized design to inform development of a larger randomized controlled trial. ³ , ⁴

An important limitation of MIPD is that its clinical benefit is highly dependent on successful implementation. Already for ‘simple’ empirical dose reduction strategies, we identified multiple factors that required more attention, including lack of time during consultations as an important barrier, and physicians expressed a clear need for more education, guidelines and scientific evidence of dose reduction strategies. Additional barriers are expected in more complex interventions like TDM‐based strategies. As highlighted by Dibbets et al., barriers such as limited infrastructure, insufficient clinician training, suboptimal workflow integration and model complexity may prevent MIPD from achieving its full potential in dermatology practice. ⁵ But as Eylenbosch et al. also describe, there is reason for optimism, as increasing opportunities exist to integrate user‐friendly MIPD software into electronic health records and to enable patients to measure drug levels at home. They also mention the possibility of adding other variables into decision‐support dashboards; this may be essential as pharmacologic nonresponse is mostly determined by a mismatch in drug target and immune module dominance, and big steps are made to bring molecular precision medicine to practice. ⁶

In conclusion, MIPD offers a clear conceptual improvement over traditional TDM and its goal of personalized dosing aligns well with current clinical, economic and sustainability goals. However, its widespread adoption in dermatology should be guided by high‐quality diagnostic trials, robust model validation and pragmatic implementation strategies that ensure real‐world clinical benefit.

FUNDING INFORMATION

Not applicable.

CONFLICT OF INTEREST STATEMENT

None to be declared.

van den Reek JMPA, de Jong EMGJ. Bridging theory and practice in model‐informed precision dosing of medication in inflammatory skin diseases. J Eur Acad Dermatol Venereol. 2026;40:339–340. 10.1111/jdv.70300

DATA AVAILABILITY STATEMENT

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.