Final analysis of the KEYNOTE-811 study: Pembrolizumab combination therapy significantly improves survival in HER2-positive gastric cancer
Breakthrough results
Dr. Sara Lonardi of the Veneto Cancer Institute in Padua, Italy, reports:
Median overall survival: 20.0 months (16.8 months in control group, HR=0.80)
36-month survival rate: 28% vs 23%
PD-L1 positive (CPS≥1) patients showed more significant benefit (HR=0.79)
Study Design and Key Data
Parameters
Pembrolizumab Group
Placebo Group
Sample Size
350 cases
348 cases
Treatment Regimen
Pembrolizumab + Trastuzumab + Chemotherapy (CAPOX/FP)
Placebo + Trastuzumab + Chemotherapy
Median PFS
10.0 months
8.1 months (HR=0.73)
Objective Response Rate
72.6%
60.1%
Duration of Response
11.3 months
9.5 months
Subgroup Analysis Highlights:
PD-L1 Expression:
Patients with CPS ≥ 1 showed a 21% reduction in mortality risk.
Patients with CPS < 1 showed no benefit (15%).
Racial Differences:
Asian patients did not show a statistically significant benefit (HR = 1.05).
Non-Asian patients had an HR of 0.72.
Safety Characteristics
Serious adverse events: 26% vs 23%
Common toxicities: diarrhea, nausea, anemia (mainly from chemotherapy)
Treatment discontinuation rate: 37% vs 34%
Clinical Significance
Professor Filippo Pietrantonio of the National Cancer Institute of Milan emphasized:
"For HER2-positive gastric cancer patients with PD-L1 CPS ≥ 1, pembrolizumab combination therapy should be the first-line standard of care. For patients with CPS < 1, trastuzumab plus chemotherapy is still recommended."
This study was sponsored by Merck; complete data can be found at ESMO 2024.
Source: https://ascopost.com/issues/december-10-2024-supplement-conference-highlights-esmo-2024/keynote-811-pembrolizumab-combination-in-first-line-setting-improves-overall-survival-in-gastric-cancer/