Combination therapy for inflammatory bowel disease

Table 1 Author’s summary of the evidence for combination therapy

	Crohn’s disease		Ulcerative colitis
	Clinical benefit	Pharmacokinetic/immunogenic benefit	Clinical benefit	Pharmacokinetic/immunogenic benefit
IFX + AZA/6MP (treatment naïve)	+	+	+	+
IFX + AZA/6MP (step-up from immunomodulator monotherapy)	-	NA	NA	NA
IFX + MTX	+/-	+	NA	NA
ADA + IMM	+/-	+/-	NA	NA
VDZ + IMM	NA	+	NA	NA
Ustekinumab +	NA	NA	NA	NA
IMM

IFX: Infliximab; AZA: Azathioprine; 6-MP: 6-mercaptopurine; MTX: Methotrexate; ADA: Adalimumab; VDZ: Vedolizumab; IMM: immunomodulatory; +: beneficial; +/-: Possible benefit; NA: No adequate data available.

Table 2 Summary: Major society guidelines addressing combination therapy

	CD	UC
American College of Gastroenterology (2009 CD, 2010 UC)	IFX or IFX and AZA superior to AZA	Unknown efficacy of CT
European Crohn’s and Colitis Organization and World Congress of Gastroenterology (2011)	IFX and AZA superior to monotherapy (in treatment naïve)	Unknown efficacy of CT
American Gastroenterological Association (CD guidelines (2013)	Anti-TNF-α and AZA superior to monotherapy
American Gastroenterological Association Clinical Care Pathways (2014 CD, 2015 UC)	Consider IMM with anti-TNF-α or 2nd/3rd line biologic	Consider IMM with all anti-TNF-α or VDZ use
Hong Kong IBD Society (2013)	Anti-TNF-α and AZA superior to monotherapy	CT not addressed
Indian Society of Gastroenterology (UC consensus)		CT not addressed
Asian Pacific Association of Gastroenterology (UC consensus)		CT not addressed
Japanese Society of Gastroenterology (CD guidelines)	CT Not addressed

IFX: Infliximab; AZA: Azathioprine; IMM: Immunomodulator (includes AZA, 6-mercaptopurine, Methotrexate); VDZ: Vedolizumab; CT: Combination therapy; UC: Ulcerative colitis; CD: Crohn’s disease.