Bringing drug monitoring closer to the patient

The management of inflammatory bowel disease (IBD) is continuing to evolve at pace, with the introduction of subcutaneous injections and now discussions about orally administered biological medications. This is opening up the possibility for at-home and patient-led IBD management, relieving the pressures on clinical care settings. However, this also calls into question the need for point-of-care or clinic-based therapeutic drug monitoring (TDM), and encourages the adoption of remote sampling for TDM to work in parallel with at-home therapies. This article will discuss the developments that have been made to make at-home TDM sampling a reality, and highlights what this could mean for the future of IBD management.

The pharmacological management of IBD has advanced dramatically in the last few decades, improving the prognosis for the 25,000 patients diagnosed with the condition every year in the UK.¹ This has included the introduction of biologics — such as the TNF-α inhibitors infliximab and adalimumab — alongside immunomodulators and other monoclonal antibodies, such as anti-integrins. Biologics play a crucial role in IBD management by blocking pro-inflammatory cytokines, and there has been a drastic decrease in the need for surgical procedures² since their introduction into routine clinical practice.

However, a significant proportion of patients who are offered these therapies either fail to respond during induction or develop a loss of response (LOR) over the course of months or even years. For example, approximately 30 percent of patients do not respond to anti-TNF-α primarily,³ and one study found that up to 46 percent of patients with Crohn's disease stopped responding to anti-TNF-α therapies within a year of starting treatment.⁴ This is often the result of the body's immune system developing anti-drug antibodies (ADAs) that can impact the pharmacokinetics, pharmacodynamics and efficacy of the drug, leading to lower drug trough levels in the bloodstream. Drug unresponsiveness can have huge consequences for patient management, not least by losing control of the symptoms — with one study reporting that 63 percent of patients were still in non-remission after 54 weeks⁵ — but also by discouraging adherence to treatment.