Creative Commons Attribution-Non Commercial 4.0 December 2020 • GASTROENTEROLOGY 91 An Overview of Novel and Emerging Therapies for Infammatory Bowel Disease Abstract Infammatory bowel disease, consisting of Crohn’s disease and ulcerative colitis, causes chronic gastrointestinal symptoms and can lead to morbidity and mortality if uncontrolled or untreated. However, for patients with moderate-to-severe disease, currently available therapies do not induce or maintain remission in >50% of patients. This underscores the need for additional therapies. In this review, the authors detail the novel therapies vedolizumab, tofacitinib, and ustekinumab and delve into therapies which may come onto the market within the next 10 years, including JAK-1 inhibitors (flgotinib and upadacitinib), IL-23 inhibitors (guselkumab, mirikizumab, and risankizumab), the anti-β4β7 and anti-βEβ7 integrin monoclonal antibody etrolizumab, the sphingosine-1-phosphate subtypes 1 and 5 modulator ozanimod, and mesenchymal stem cells. Further studies are required before these emerging therapies gain approval. INTRODUCTION Infammatory bowel disease (IBD), consisting primarily of ulcerative colitis (UC) and Crohn’s disease (CD), are chronic diseases afecting the gastrointestinal tract. Symptoms include diarrhoea, with and without blood, and abdominal pain. UC and CD, if left untreated or uncontrolled, cause signifcant morbidity and mortality at rates higher than the general population. 1 Furthermore, the incidence and prevalence of IBD are increasing over time around the globe. 2 Standard therapies in IBD include topical 5-aminosalicylate products such as mesalamine and sulfasalazine, thiopurines such as azathioprine and 6-mercaptopurine, and topical and systemic corticosteroids. Unfortunately, topical 5-aminosalicylate products are not recommended in moderate-to-severe UC because of a lack of efcacy in this cohort. 3 Thiopurines are only efective in about one- quarter of patients, 4 and corticosteroids are not recommended for maintenance of remission as a result of dose-dependent short and long-term adverse efects, such as increased risk of serious infection, weight gain, elevated blood sugar levels, bone loss, and cataracts. 5, 6 Authors: Sumona Bhattacharya, 1 Raymond K. Cross 2 1. Digestive Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, Maryland, USA 2. University of Maryland School of Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, Baltimore, Maryland, USA *Correspondence to rcross@som.umaryland.edu Disclosure: Dr Bhattacharya has declared no conficts of interest. Dr Cross has received income from consulting and participation in advisory boards for AbbVie, Janssen, Pfzer, Samsung Bioepis, and Takeda, outside of the submitted work. Received: 02.07.20 Accepted: 30.09.20 Keywords: Biologic therapy, Crohn's disease (CD), infammatory bowel disease (IBD), JAK inhibition, ulcerative colitis (UC). Citation: EMJ Gastroenterol. 2020;9[1]:91-101.