The goal of therapeutic drug monitoring (TDM) is to optimize anti-TNF (tumor necrosis factor) biologic treatment in patients with inflammatory bowel disease (IBD). Although commercial assays are readily available for both ustekinumab and vedolizumab, the use of TDM with these newer biologic medications is at its infancy. The clinical utility of TDM with non-anti-TNF mechanisms of action is not clear. This review summarizes the latest available data on the pharmacokinetics of newer biologic and oral small molecules and highlights the threshold concentrations that have been associated with improved outcomes in IBD patients.

Background: The medical treatment of fistulizing Crohn’s disease (CD) remains a challenge to clinicians. Over the last 20 years, biologic therapies have been the mainstay of medical treatment of fistulizing CD. The purpose of this study is to compare the efficacy of biologic therapies in inducing response and remission in fistulizing CD. Methods: We performed a systematic review of the EMBASE, MEDLINE, and Cochrane Central databases from inception to December 2021. Inclusion criteria were any randomized controlled trials (RCTs) that evaluated the efficacy of biologic therapies against an active comparator or placebo for induction of response or remission in adults with fistulizing CD. The proportion of patients with fistula response or remission, as defined by each clinical trial, was our primary study outcome. A Bayesian random-effects network meta-analysis was used to measure treatment effects and results were reported as odds ratio (OR) and 95% confidence interval (CI). Results: In our analysis, 10 studies were included, and all were RCTs. Infliximab was superior to adalimumab in inducing response (OR, 0.24; 95% CI, 0.06-0.99) but not in inducing remission (OR, 0.31; 95% CI, 0.04-2.27). Tumor necrosis factor antagonists were superior to placebo in the induction of response (OR, 0.51; 95% CI, 0.35-0.750) and remission (OR, 0.36; 95% CI, 0.22-0.58). Infliximab was superior to placebo in inducing response (OR, 0.36; 95% CI, 0.17-0.75) and remission (OR, 0.17; 95% CI, 0.03-0.87). Ustekinumab was superior to placebo in inducing response (OR, 0.48; 95% CI, 0.26-0.860) but not in inducing remission (OR, 0.50; 95% CI, 0.13-1.93). When comparing biologic therapies against each other, there was no statistical difference in inducing remission. Vedolizumab was not superior to placebo in inducing remission (OR, 0.32; 95% CI, 0.04-2.29). Certolizumab was not superior to placebo in inducing response (OR, 0.78; 95% CI, 0.40-1.55) or remission (OR, 0.78; 95% CI, 0.40-1.55). Conclusions: Tumor necrosis factor antagonists are effective in inducing response and remission in fistulizing CD. Infliximab was superior to adalimumab for inducing response but not for inducing remission. Ustekinumab is effective in the induction of response but not in the induction of remission. When compared against each other, biologic therapies showed no significant difference in the induction of remission. Based on the available data, infliximab is the preferred first-line treatment. As for other biologics, the limited published data do not allow us to make firm recommendations. This study supports current practice and emphasizes the need for dedicated RCTs to evaluate the efficacy of biologic therapies in fistulizing CD.

Inflammatory bowel disease (IBD) affects patients during their peak reproductive years. This raises important questions, in both patients and healthcare providers, regarding conception, pregnancy, and breastfeeding. Lack of information and insufficient communication among healthcare providers can leave patients with limited information and even contradictory advice. Given the fact that pregnant and/or breastfeeding IBD patients are excluded from clinical studies the evidence on many questions related to pregnancy and postpartum period is limited. However, there exists increasing data from case series and cohort studies that allows to provide clinical guidance. The overarching concept is that optimizing the mother’s health is critical for optimizing the health of the unborn child and benefit of continuing medical therapy in IBD during pregnancy outweighs possible risks in most instances. This paper provides an up-to-date systematic review of the literature on IBD in pregnancy and proposes guidance to questions frequently encountered by healthcare professionals.

Patients with inflammatory bowel disease (IBD) are prone to reduced bone mineral density and elevated overall fracture risk. Osteopenia affects up to 40% of patients with IBD (high regional variability). Besides disease activity, IBD specialists must consider possible side effects of medication and the presence of associated diseases and extraintestinal manifestations. Osteopenia and osteoporosis remain frequent problems in patients with IBD and are often underestimated because of widely differing screening and treatment practices. Malnutrition, chronic intestinal inflammation and corticosteroid intake are the major pathophysiological factors contributing to osteoporosis. Patients with IBD are screened for osteoporosis using dual-energy X-ray absorptiometry (DXA), which is recommended for all patients with a prolonged disease course of more than three months, with repeated corticosteroid administration, aged >40 years with a high FRAX risk score or aged <40 years with multiple risk factors. From a therapeutic perspective, besides good disease control, vitamin D supplementation and glucocorticoid sparing, several specific osteological options are available: bisphosphonates, receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors (denosumab), parathyroid hormone (PTH) analogues and selective estrogen receptor modulators. This review provides an overview of the pathophysiology, diagnosis, prevention and treatment of IBD-associated bone loss.