RT Journal Article SR Electronic T1 Challenges and opportunities for IBD drug development: from early stage to regulatory approval JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1157 OP 1161 DO 10.1136/gutjnl-2019-320542 VO 69 IS 7 A1 Silvio Danese A1 Elmer Schabel A1 Mark Andrew Ainsworth A1 Laurent Peyrin-Biroulet YR 2020 UL http://gut.bmj.com/content/69/7/1157.abstract AB