Table 2 Clinical trials of immune checkpoint blockade in EC

PD-1

Pembrolizumab

Pembrolizumab alone

IB

Keynote-028

ORR 30% in PD-L1⁺ EC

Pembrolizumab alone

II

Keynote-180 (NCT02559687)

ORR 14.3% in ESCC and 5.2% in EAC

Pembrolizumab vs. irinotecan or taxanes

III

Keynote-181 (NCT02564263)

Median OS in ESCCs: 8.2 vs. 7.1 months

ORR in ESCCs: 16.7% vs. 7.4%

Pembrolizumab + cisplatin and 5-fluorouracil vs. placebo

III

Keynote-590 (NCT03189719)

Ongoing

PD-1

Nivolumab

Nivolumab vs. taxanes

III

NCT02569242

Median OS in ESCCs: 10.9 vs. 8.4 months

Nivolumab alone

II

JapicCTI-142422

17% of ESCC patients had a centrally assessed objective response

Nivolumab vs. placebo

III

Checkmate-577 (NCT02743494)

Ongoing

Nivolumab + ipilimumab or nivolumab + fluorouracil + cisplatin vs. fluorouracil + cisplatin

III

Checkmate-648 (NCT03143153)

Ongoing

SHR-1210

SHR-1210 alone

I

NCT0274293

ORR 30% and median PFS 3.6 months in ESCC

SHR-1210 vs. docetaxel or irinotecan

III

NCT03099382

N/A

CTLA-4

Ipilimumab

N/A

I

NCT01738139

Ongoing

PD-1/CTLA-4

Nivolumab/ipilimumab

Nivolumab (3 mg/kg) vs. nivolumab (1 mg/kg) + ipilimumab (3 mg/kg) vs. nivolumab (3 mg/kg) + ipilimumab (1 mg/kg)

I/II

CheckMate-032

ORR in patients with gastric, esophageal, or gastroesophageal junction cancer: 12% vs. 24% vs. 8%