Is the combination of immunotherapy with conventional chemotherapy the key to increase the efficacy of colorectal cancer treatment?

Table 1 Types of immune checkpoint inhibitor antibodies used as monotherapy, combined immune checkpoint inhibitor, and immune checkpoint inhibitor + chemotherapy in colorectal cancer

Antibody name	Isotype	Target molecule	Effectiveness1 as monotherapy	Effectiveness as combined ICI	Effectiveness as ICI + chemotherapy	Ref.
Ipilimumab	IgG1	CTLA4	Yes	Well tolerated in combination with nivolumab	No	Suzuki et al[80], 2021; Lenz et al[86], 2022; Cohen et al[90], 2020
Tremelimumab	IgG2	CTLA4	No	Yes, durvalumab improved OS and increased lymphoid response	Combined with durvalumab + fluoropyrimidines, oxaliplatin, irinotecan, showed increased OS	Chung et al[77], 2010; Kanikarla Marie et al[85], 2021; Chen et al[102], 2020
Nivolumab	IgG4	PD1	Well tolerated	Well tolerated in combination with low ipilimumab dose, with increased OS	Yes	Overman et al[78], 2017; Kawazoe et al[79], 2021; Lenz et al[86], 2022; Morse et al[87], 2019
Pembrolizumab	IgG4	PD1	Well tolerated, increased OS	No	There is no evidence	Haag et al[82], 2022
Atezolizumab	IgG1	PDL1	There is no evidence	There is no evidence	Safe when combined with cobimetinib, having no effect on OS. Combined with FOLFOX and bevacizumab showed increased progression-free survival, but adverse events were shown	Eng et al[91], 2019; Antoniotti et al[94], 2022
Avelumab	IgG1	PDL1	Increased OS but adverse events were shown	There is no evidence	Combined with cetuximab showed increased T cell killing	Haag et al[82], 2022; Stein et al[97], 2021
Durvalumab	IgG1	PDL1	Increased progression-free survival, but adverse events were shown	There is no evidence	Safe when combined with MEKi, having no effect on OS	Oh et al[84], 2022

¹Effectiveness was considered as increased survival, well tolerated treatment in patients, or simply a lack of side effects associated with the treatment.

IgG: Immunoglobulin G; OS: Overall survival; PDL1: Programmed cell death ligand 1; PD1: Programmed cell death 1; CTLA4: Cytotoxic T-lymphocyte-associated protein 4; ICI: Immune checkpoint inhibitor; FOLFOX: 5-FU therapy with leucovorin and oxaliplatin; MEKi: Inhibitor of MAPK/ERK kinase.