OBJECTIVES : Ulcerative colitis (UC) is the most common form of inflammatory bowel disease. The goal of treatment in UC is to induce and maintain remission, however, there is currently no fully validated definition of remission in UC. A literature review explored the variation of remission in clinical trials of UC and the impact this may have on HTA decision making for mild to moderate UC.

METHODS : The MEDLINE database was searched for publications and clinical trials on first-line treatment of active mild to moderate UC with remission as a primary outcome. Published HTAs for steroid treatment of active mild to moderate UC were also reviewed.

RESULTS : Remission has been an outcome in clinical trials of UC since 1955. Remission is increasingly defined by both clinical parameters and endoscopic criteria, and so the definition of remission has become more stringent. A systematic review was identified which found that over 50 definitions of response and remission had been used across 83 trials from 1987 to 2017. In the TLV assessment in Sweden of budesonide MMX for UC, its efficacy compared to other UC treatments was deemed to be uncertain due to use of different definitions of remission in indirect comparisons. However, its association with fewer adverse events (AEs) compared to oral systemic corticosteroids allowed it to be classed as cost-effective, and subsequently recommended for a subpopulation of UC patients.

CONCLUSIONS : Variation in definition of remission across clinical trials of UC limits the ability to perform indirect comparisons for efficacy. Therefore in HTAs, it may be easier to indirectly compare new treatments when considering tolerability rather than efficacy. The first International Consensus on the definition of endoscopic remission in UC was published in 2017. This may lead to greater consistency in the definition of remission in future UC trials and facilitate network meta-analyses.