Personalized Dosing of Infliximab in Patients with Inflammatory Bowel Disease using a Bayesian Approach: A Next Step in Therapeutic Drug Monitoring.

Although biological agents have revolutionized the management of inflammatory bowel diseases (IBD), a significant proportion of patients show primary non-response or develop secondary loss of response. Therapeutic drug monitoring (TDM) is advocated to maintain the efficacy of biologic agents. Reactive TDM can rationalize the management of primary non response and secondary loss of response and has shown to be more cost effective compared to empiric dose escalation. Proactive TDM is shown to increase clinical remission and durability of response to biologic agent. However, the efficacy of proactive and reactive TDM has been questioned in recent studies and metanalyses. Hence, we need a different approach to TDM, which addresses inflammatory burden, individual patient and disease factors. Bayesian approaches, which use population pharmacokinetic models, enables clinicians to make better use of TDM for dose adjustments. With rapid improvement in computer technology, these Bayesian model-based software packages are now available for clinical use. Bayesian Dashboard systems allow clinicians to apply model-based dosing to understand an individual's pharmacokinetics and achieve a target serum drug concentration. The model is updated using previously measured drug concentrations and relevant patient factors such as body weight, C-reactive protein, and serum albumin concentration, to maintain effective drug concentrations in the serum. Initial studies have found utility of Bayesian approach in induction and maintenance, in adult and paediatric patients, in clinical trials and real-life situation in patients with IBD treated with infliximab. This needs confirmation in larger studies This article reviews Bayesian approach to therapeutic drug monitoring in IBD. This article is protected by copyright. All rights reserved.