Is personal physiology-based rapid prediction digital twin for minimal effective fentanyl dose better than standard practice: a pilot study protocol.

Introduction
Patients with advanced cancer frequently suffer from chronic, severe disabling pain. Opioids such as morphine and fentanyl are commonly used to manage this pain. Transdermal drug delivery systems are important technologies for administering drugs in a non-invasive, continuous and controlled manner. Due to the narrow therapeutic range of fentanyl, individualised dosing is essential to avoid underdosing or overdosing. Standard clinical calculation tools for opioid rotation however do not include important patient characteristics that account for interindividual variability of opioid pharmacology.Methods And Analysis
We developed a clinical protocol to optimise individual fentanyl dosing in patients with advanced cancer switching from oral or intravenous opioids to transdermal fentanyl by using a physics-based digital twin (DT) that is fed by important clinical and physiological parameters. Individual tailoring of transdermal fentanyl therapy is an approach with the potential for personalised and effective care with an improved benefit-risk ratio. However, clinical validation of physics-based digital twins (PBDT) dosing is crucial to proving clinical benefit.Therapeutic drug monitoring will allow to validate the accuracy of PBDT predictions. Additional monitoring for breathing dynamics, sequential pain levels and fentanyl-related adverse events will contribute to evaluating the performance of PBDT-based dosing of transdermal fentanyl. The primary objective of the study is to develop an experimental protocol to validate DT-guided fentanyl dosing in patients with advanced cancer. This clinical study will bring individualised opioid dosing closer to clinical practice.Ethics And Dissemination
Study documents have been approved by the responsible Ethics Committee and study initiation is planned for late summer 2024. Data will be shared with the scientific community no more than 1 year following completion of the study and data assembly.