Table 1.

Characteristics of included studies

Trial/ Median follow‐up	Study arm (num patients)	Control arm (num patients)	Line of treatment	Median Age (years)	Asians (%)	Male (%)	ECOG PS = 0 (%)	Primary location: stomach (%)	Diffuse subtype (%)	Other
ATTRACTION‐2, Kang 2017, 18 , 19 (8.8 months)	Nivolumab 3 mg/kg q 2‐week (330)	Placebo (163)	≥3	62	100%	71%	29%	83%	34%	PDL1 positive: 14%
JAVELIN gastric 300, Bang 2018 20 (10.6 months)	Avelumab 10mg/kg q 2‐week (185)	paclitaxel 80 mg/m2 d1,8,15 OR irinotecan 150 mg/m2 q 4‐week OR BSC c (186)	3	60	25%	72%	35%	70%	21%	PDL1 ≥ 1%: 27%
KEYNOTE 061, Shitra 2018 16 , a (7.9 months)	Pembrolizumab 200 mg q 3‐week (196)	paclitaxel 80 mg/m2 d1,8,15 week (199)	2	62.5	30%	74%	46%	66%	23%	CPS ≥ 1%: 100% HER2 +: 19% MSI‐H*: 5%
KEYNOTE 062, Shitara 2019, 17 , 21 , b (11.3 months)	Pembrolizumab 200 mg q 3‐week (256)	Placebo + cisplatin 80 mg/m2 + 5FU 800mg/m2 d1‐5 OR capecitabine twice a day 1‐14 q 3‐week (250)	1	62	24%	71%	49%	71%	45%	CPS ≥ 1%: 100% HER2 +: 0% MSI‐H: 7%
JAVELIN gastric 100, Moehler 2020 22	Avelumab 10 mg/kg q 2‐week (249)	Oxaliplatin + 5FU+LCV/ capecitabine OR BSC d (250)	Maintenance after 1st line without progression	61.5	23%	66%	42%	71%	‐	PDL1 ≥ 1%: 12% CPS ≥ 1%: 22% d , e HER2 +: 0% MSI‐H: 3%

Abbreviations: 5FU, 5‐fluorouracil; BSC, best supportive care; ECOG PS, Eastern Cooperative Oncology Group performance status; HER2, human epidermal growth factor receptor 2; LCV, leucovorin; MSI‐H, microsatellite instability—high; PDL1, programmed death ligand.

^aOnly the patients with CPS ≥ 1 were included.

^bData from the experimental arm with pembrolizumab monotherapy were included.

^cThree patients received BCS only.

^dChoice of chemotherapy of BCS decided by investigators prior randomization, a total pf 19 patients did not receive chemotherapy.

^eStratification to PDL1 + was done using the 73‐10 pharmDx assay (Dako), postexploratory analysis assessment of CPS was done with 22C3 pharmDx assay (Dako).