What was the median overall survival in CheckMate 648 (Japanese subgroup) (Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation))?

Reconstructed medians (Months): NIVO+Chemo 17.4; Chemo 9.2. See the published article for the official values.

What was the hazard ratio for overall survival in CheckMate 648 (Japanese subgroup) (Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation))?

The figure reports a hazard ratio of 0.53 (95% CI 0.35–0.82) for NIVO+Chemo vs Chemo. TrialCurve's reconstruction gives 0.54.

What was the median overall survival in CheckMate 648 (Japanese subgroup) (All randomized patients (Japanese subpopulation))?

Reconstructed medians (Months): NIVO+Chemo 15.5; Chemo 10.9. See the published article for the official values.

What was the hazard ratio for overall survival in CheckMate 648 (Japanese subgroup) (All randomized patients (Japanese subpopulation))?

The figure reports a hazard ratio of 0.73 (95% CI 0.54–0.99) for NIVO+Chemo vs Chemo. TrialCurve's reconstruction gives 0.714.

What was the median progression-free survival per bicr in CheckMate 648 (Japanese subgroup) (Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation))?

Reconstructed medians (Months): NIVO+Chemo 7.0; Chemo 3.9. See the published article for the official values.

What was the hazard ratio for progression-free survival per bicr in CheckMate 648 (Japanese subgroup) (Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation))?

The figure reports a hazard ratio of 0.56 (95% CI 0.36–0.89) for NIVO+Chemo vs Chemo. TrialCurve's reconstruction gives 0.554.

What was the median progression-free survival per bicr in CheckMate 648 (Japanese subgroup) (All randomized patients (Japanese subpopulation))?

Reconstructed medians (Months): NIVO+Chemo 7.0; Chemo 4.1. See the published article for the official values.

What was the hazard ratio for progression-free survival per bicr in CheckMate 648 (Japanese subgroup) (All randomized patients (Japanese subpopulation))?

The figure reports a hazard ratio of 0.76 (95% CI 0.56–1.03) for NIVO+Chemo vs Chemo. TrialCurve's reconstruction gives 0.762.

What was the median duration of response per bicr in CheckMate 648 (Japanese subgroup)?

Reconstructed medians (Months): NIVO+IPI 10.0; Chemo 6.9. See the published article for the official values.

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CheckMate 648 (Japanese subgroup): reconstructed Kaplan–Meier curves

Updated 2026-09-25 · reconstructed by TrialCurve from a CC BY-licensed publication

First-line nivolumab plus ipilimumab or chemotherapy versus chemotherapy alone in advanced esophageal squamous cell carcinoma: a Japanese subgroup analysis of open-label, phase 3 trial (CheckMate 648/ONO-4538-50). Curves rebuilt as patient-level data (Guyot 2012) and checked against the statistics printed on the figure.

Publication	Esophagus. 2022 Nov 19;20(2):291–301. doi: 10.1007/s10388-022-00970-1
DOI	10.1007/s10388-022-00970-1
Registry	NCT03143153
Phase	Phase 3
Conditions	Various Advanced Cancer
Interventions	Nivolumab, Ipilimumab, Cisplatin, Fluorouracil
Sponsor	Bristol-Myers Squibb
Enrolment	970
Source licence	Figure published under CC BY 4.0

Overall survival — Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation)

From figure panel a · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+IPI 20.3 months; Chemo 8.9 months. Survival at 12 months: NIVO+IPI 70%; Chemo 37%. Hazard ratio NIVO+IPI vs Chemo 0.46 (95% CI 0.29–0.71).

Arm	N	Events	Median (Months)
NIVO+IPI	66	37	20.3
Chemo	65	50	8.9

NIVO+IPI vs Chemo: reconstructed HR 0.46 (95% CI 0.29–0.71)

Landmark survival (reconstructed)

Time	NIVO+IPI	Chemo
6 mo	86.0%	75.0%
12 mo	70.3%	36.7%
18 mo	53.3%	18.5%
24 mo	45.0%	18.5%
36 mo	34.7%	—

Checks against the published figure

NIVO+IPI median: printed 20.2, reconstructed 20.3 pass
Chemo median: printed 9, reconstructed 8.9 pass
hazard ratio: printed 0.46, reconstructed 0.456 pass

Download pseudo-IPD (CSV)

Overall survival — All randomized patients (Japanese subpopulation)

From figure panel b · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+IPI 17.1 months; Chemo 10.8 months. Survival at 12 months: NIVO+IPI 62%; Chemo 47%. Hazard ratio NIVO+IPI vs Chemo 0.69 (95% CI 0.51–0.93).

Arm	N	Events	Median (Months)
NIVO+IPI	131	81	17.1
Chemo	137	96	10.8

NIVO+IPI vs Chemo: reconstructed HR 0.69 (95% CI 0.51–0.93)

Landmark survival (reconstructed)

Time	NIVO+IPI	Chemo
6 mo	86.8%	78.1%
12 mo	62.3%	46.9%
18 mo	48.2%	29.9%
24 mo	36.3%	24.7%
36 mo	29.0%	—

Checks against the published figure

NIVO+IPI median: printed 17.6, reconstructed 17.1 pass
Chemo median: printed 11, reconstructed 10.8 pass
hazard ratio: printed 0.68, reconstructed 0.687 pass

Download pseudo-IPD (CSV)

Progression-free survival per BICR — Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation)

From figure panel c · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+IPI 5.4 months; Chemo 4.1 months. Survival at 12 months: NIVO+IPI 29%; Chemo 11%. Hazard ratio NIVO+IPI vs Chemo 0.81 (95% CI 0.52–1.28).

Arm	N	Events	Median (Months)
NIVO+IPI	66	45	5.4
Chemo	65	37	4.1

NIVO+IPI vs Chemo: reconstructed HR 0.81 (95% CI 0.52–1.28)

Landmark survival (reconstructed)

Time	NIVO+IPI	Chemo
6 mo	37.1%	30.0%
12 mo	28.7%	11.4%
18 mo	23.9%	—
24 mo	23.9%	—

Checks against the published figure

NIVO+IPI median: printed 5.4, reconstructed 5.38 pass
Chemo median: printed 4.2, reconstructed 4.12 pass
hazard ratio: printed 0.84, reconstructed 0.811 pass

Download pseudo-IPD (CSV)

Progression-free survival per BICR — All randomized patients (Japanese subpopulation)

From figure panel d · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+IPI 4.1 months; Chemo 4.1 months. Survival at 12 months: NIVO+IPI 24%; Chemo 17%. Hazard ratio NIVO+IPI vs Chemo 1.08 (95% CI 0.80–1.46).

Arm	N	Events	Median (Months)
NIVO+IPI	131	96	4.1
Chemo	137	80	4.1

NIVO+IPI vs Chemo: reconstructed HR 1.08 (95% CI 0.80–1.46)

Landmark survival (reconstructed)

Time	NIVO+IPI	Chemo
6 mo	33.8%	35.1%
12 mo	24.0%	17.2%
18 mo	17.7%	14.3%
24 mo	17.7%	14.3%

Checks against the published figure

NIVO+IPI median: printed 4.2, reconstructed 4.1 pass
Chemo median: printed 4.3, reconstructed 4.14 pass
hazard ratio: printed 1.16, reconstructed 1.08 pass

Download pseudo-IPD (CSV)

Duration of response per BICR — Responders among all randomized patients (Japanese subpopulation)

From figure panel f · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+IPI 10.0 months; Chemo 6.9 months. Survival at 12 months: NIVO+IPI 50%; Chemo 29%. Hazard ratio NIVO+IPI vs Chemo 0.73 (95% CI 0.39–1.37).

Arm	N	Events	Median (Months)
NIVO+IPI	47	23	10.0
Chemo	33	18	6.9

NIVO+IPI vs Chemo: reconstructed HR 0.73 (95% CI 0.39–1.37)

Landmark survival (reconstructed)

Time	NIVO+IPI	Chemo
6 mo	69.0%	50.1%
12 mo	49.7%	29.5%
18 mo	40.4%	29.5%
24 mo	40.4%	29.5%

Checks against the published figure

NIVO+IPI median: printed 9.9, reconstructed 9.98 pass
Chemo median: printed 6.9, reconstructed 6.86 pass

Download pseudo-IPD (CSV)

Overall survival — Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation)

From figure panel a · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+Chemo 17.4 months; Chemo 9.2 months. Survival at 12 months: NIVO+Chemo 64%; Chemo 36%. Hazard ratio NIVO+Chemo vs Chemo 0.54 (95% CI 0.35–0.82).

Arm	N	Events	Median (Months)
NIVO+Chemo	62	39	17.4
Chemo	65	50	9.2

NIVO+Chemo vs Chemo: reconstructed HR 0.54 (95% CI 0.35–0.82)

Landmark survival (reconstructed)

Time	NIVO+Chemo	Chemo
6 mo	87.1%	77.6%
12 mo	64.4%	35.6%
18 mo	48.2%	17.6%
24 mo	46.0%	17.6%

Checks against the published figure

NIVO+Chemo median: printed 17.3, reconstructed 17.4 pass
Chemo median: printed 9, reconstructed 9.25 pass
hazard ratio: printed 0.53, reconstructed 0.54 pass

Download pseudo-IPD (CSV)

Overall survival — All randomized patients (Japanese subpopulation)

From figure panel b · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+Chemo 15.5 months; Chemo 10.9 months. Survival at 12 months: NIVO+Chemo 61%; Chemo 46%. Hazard ratio NIVO+Chemo vs Chemo 0.71 (95% CI 0.53–0.97).

Arm	N	Events	Median (Months)
NIVO+Chemo	126	77	15.5
Chemo	137	95	10.9

NIVO+Chemo vs Chemo: reconstructed HR 0.71 (95% CI 0.53–0.97)

Landmark survival (reconstructed)

Time	NIVO+Chemo	Chemo
6 mo	85.4%	77.9%
12 mo	60.9%	46.3%
18 mo	43.7%	30.4%
24 mo	38.9%	25.2%
36 mo	22.0%	—

Checks against the published figure

NIVO+Chemo median: printed 15.5, reconstructed 15.5 pass
Chemo median: printed 11, reconstructed 10.9 pass
hazard ratio: printed 0.73, reconstructed 0.714 pass

Download pseudo-IPD (CSV)

Progression-free survival per BICR — Patients with tumor-cell PD-L1 >=1% (Japanese subpopulation)

From figure panel c · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+Chemo 7.0 months; Chemo 3.9 months. Survival at 12 months: NIVO+Chemo 29%; Chemo 12%. Hazard ratio NIVO+Chemo vs Chemo 0.55 (95% CI 0.35–0.88).

Arm	N	Events	Median (Months)
NIVO+Chemo	62	46	7.0
Chemo	65	37	3.9

NIVO+Chemo vs Chemo: reconstructed HR 0.55 (95% CI 0.35–0.88)

Landmark survival (reconstructed)

Time	NIVO+Chemo	Chemo
6 mo	55.1%	30.5%
12 mo	29.0%	12.4%
18 mo	12.4%	—
24 mo	12.4%	—

Checks against the published figure

NIVO+Chemo median: printed 7, reconstructed 7.05 pass
Chemo median: printed 4.2, reconstructed 3.88 pass
hazard ratio: printed 0.56, reconstructed 0.554 pass

Download pseudo-IPD (CSV)

Progression-free survival per BICR — All randomized patients (Japanese subpopulation)

From figure panel d · validated against the values printed on the figure · curve source: vision model

Reconstructed from the published curve. Median: NIVO+Chemo 7.0 months; Chemo 4.1 months. Survival at 12 months: NIVO+Chemo 24%; Chemo 18%. Hazard ratio NIVO+Chemo vs Chemo 0.76 (95% CI 0.56–1.04).

Arm	N	Events	Median (Months)
NIVO+Chemo	126	95	7.0
Chemo	137	77	4.1

NIVO+Chemo vs Chemo: reconstructed HR 0.76 (95% CI 0.56–1.04)

Landmark survival (reconstructed)

Time	NIVO+Chemo	Chemo
6 mo	51.6%	35.4%
12 mo	24.4%	18.3%
18 mo	14.0%	15.3%
24 mo	12.2%	15.3%
36 mo	12.2%	—

Checks against the published figure

NIVO+Chemo median: printed 6.8, reconstructed 7.05 pass
Chemo median: printed 4.3, reconstructed 4.09 pass
hazard ratio: printed 0.76, reconstructed 0.762 pass

Download pseudo-IPD (CSV)

About these data

Pseudo-IPD reproduces the published curves and numbers at risk; the rows are not real patients. Cite the publication (DOI above) and TrialCurve. The source figure is © the authors (CC BY 4.0); the charts here are redrawn from the reconstruction.

Load these data in R or Python

# R
library(survival)
d <- read.csv("https://trialcurve.com/data/trials/checkmate-648-japanese-subgroup-1.csv")
survfit(Surv(time, event) ~ arm, data = d)
coxph(Surv(time, event) ~ arm, data = d)

# Python
import pandas as pd
from lifelines import KaplanMeierFitter
d = pd.read_csv("https://trialcurve.com/data/trials/checkmate-648-japanese-subgroup-1.csv")
for arm, g in d.groupby("arm"):
    KaplanMeierFitter().fit(g.time, g.event, label=arm).plot_survival_function()

Suggested citation: Esophagus. 2022 Nov 19;20(2):291–301. doi: 10.1007/s10388-022-00970-1 doi:10.1007/s10388-022-00970-1. Reconstructed data: TrialCurve (2026), https://trialcurve.com/trials/checkmate-648-japanese-subgroup

Report a problem with these data

Related trials

CheckMate 648: Duration of response (per BICR); Overall survival; Progression-free survival (per BICR)
RATIONALE-306 (Japanese subgroup, 3-year): Overall survival; Progression-free survival (investigator assessment)
KEYNOTE-590 (Japanese subgroup, extended follow-up): Overall survival; Progression-free survival
NEOCRTEC5010: Disease-free survival; Overall survival
NEOCRTEC5010 (long-term follow-up): Disease-free survival; Overall survival
ATTRACTION-2 (Japanese subgroup): Overall survival; Progression-free survival

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