Critical Appraisal of Filgotinib in the Treatment of Ulcerative Colitis: Current Evidence and Place in Therapy

The role of filgotinib in ulcerative colitis and Crohn's disease

Filgotinib is an oral small molecule that selectively inhibits JAK1. It is already approved for the treatment of moderately to severely active ulcerative colitis (UC). Ongoing studies are evaluating the efficacy and safety of filgotinib in Crohn's disease (CD). The purpose of this review is to summarize the available data regarding filgotinib in the management of UC and CD. We used Pubmed, Embase and clinicaltrials.gov websites to search all available data and currently ongoing studies regarding the efficacy and safety of filgotinib in inflammatory bowel diseases. Filgotinib is an effective and safe drug for the management of biologic-naive and biologic-experienced patients with moderate-to-severe UC. The same efficacy results have not been achieved in CD.

Intestinal Inflammation and Regeneration-Interdigitating Processes Controlled by Dietary Lipids in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a disease of chronic inflammatory conditions of the intestinal tract due to disturbance of the inflammation and immune system. Symptoms of IBD include abdominal pain, diarrhea, bleeding, reduced weight, and fatigue. In IBD, the immune system attacks the intestinal tract's inner wall, causing chronic inflammation and tissue damage. In particular, interlukin-6 and interlukin-17 act on immune cells, including T cells and macrophages, to amplify the immune responses so that tissue damage and morphological changes occur. Of note, excessive calorie intake and obesity also affect the immune system due to inflammation caused by lipotoxicity and changes in lipids supply. Similarly, individuals with IBD have alterations in liver function after sustained high-fat diet feeding. In addition, excess dietary fat intake, along with alterations in primary and secondary bile acids in the colon, can affect the onset and progression of IBD because inflammatory cytokines contribute to insulin resistance; the factors include the release of inflammatory cytokines, oxidative stress, and changes in intestinal microflora, which may also contribute to disease progression. However, interfering with de novo fatty acid synthase by deleting the enzyme acetyl-CoA-carboxylase 1 in intestinal epithelial cells (IEC) leads to the deficiency of epithelial crypt structures and tissue regeneration, which seems to be due to Lgr5+ intestinal stem cell function. Thus, conflicting reports exist regarding high-fat diet effects on IBD animal models. This review will focus on the pathological basis of the link between dietary lipids intake and IBD and will cover the currently available pharmacological approaches.