Excerpt:KEYTRUDA is a programmed death receptor-1 (PD-1)-blocking antibody indicated:...in combination with trastuzumab, fluoropyrimidine- and
platinum-containing chemotherapy, for the first-line treatment of patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma.
Evidence Level:Sensitive: A2 - Guideline
Excerpt:For patients with HER2-positive gastric or GEJ previously untreated, unresectable or metastatic AC, trastuzumab plus pembrolizumab is recommended, in combination with CT.
Evidence Level:Sensitive: B - Late Trials
Title:
The KEYNOTE-811 trial of dual PD-1 and HER2 blockade in HER2-positive gastric cancer
Excerpt:...phase III KEYNOTE-811 study of pembrolizumab plus trastuzumab and chemotherapy for unresectable or metastatic, HER2-positive gastric or gastro-oesophageal junction adenocarcinoma...adding pembrolizumab to trastuzumab and chemotherapy markedly reduces tumour size, induces complete responses in some participants, and significantly improves objective response rate.
DOI:https://doi.org/10.1038/s41586-021-04161-3
Evidence Level:Sensitive: B - Late Trials
Title:
LBA-4 Initial data from the phase 3 KEYNOTE-811 study of trastuzumab and chemotherapy with or without pembrolizumab for HER2-positive metastatic gastric or gastroesophageal junction (G/GEJ) cancer
Excerpt:...receive pembrolizumab 200 mg IV Q3W or placebo IV Q3W for up to 2 years or until intolerable toxicity or PD; all participants also receive trastuzumab...CAPOX was chosen for 87.1%...The combination of pembrolizumab, trastuzumab, and chemotherapy provides a substantial, statistically significant improvement in ORR compared with placebo, trastuzumab, and chemotherapy as first-line therapy for HER2-positive, metastatic G/GEJ cancer.
DOI:https://doi.org/10.1016/j.annonc.2021.06.011
Evidence Level:Sensitive: B - Late Trials
Title:
Pembrolizumab plus trastuzumab and chemotherapy for HER2+ metastatic gastric or gastroesophageal junction (G/GEJ) cancer: Initial findings of the global phase 3 KEYNOTE-811 study.
Excerpt:Confirmed ORR (95% CI) was 74.4% (66.2-81.6) for pembro + SOC vs 51.9% (43.0-60.7) for placebo + SOC (difference, 22.7 percentage points [95% CI, 11.2-33.7], P = 0.00006); CR rate was 11.3% vs 3.1% and DCR (95% CI) was 96.2% (91.4-98.8) vs 89.3 (82.7-94.0)....Adding pembro to tras and chemo resulted in a substantial, statistically significant increase in ORR versus trastuzumab and chemo alone as 1L therapy for HER2+ metastatic G/GEJ cancer...
DOI:10.1200/JCO.2021.39.15_suppl.4013
Evidence Level:Sensitive: B - Late Trials
New
Title:
FDA Approves Merck’s KEYTRUDA® (pembrolizumab) Combined With Trastuzumab and Chemotherapy as First-line Treatment in Locally Advanced Unresectable or Metastatic HER2-Positive Gastric or Gastroesophageal Junction Adenocarcinoma
Excerpt:KEYNOTE-811 (ClinicalTrials.gov, NCT03615326), a multicenter, randomized, double-blind, placebo-controlled trial that was designed to enroll 692 patients with HER2-positive advanced gastric or GEJ adenocarcinoma....At the time of the interim analysis, ORR and DOR were assessed in the first 264 patients randomized….A statistically significant improvement in ORR was demonstrated in patients randomized to KEYTRUDA in combination with trastuzumab and chemotherapy compared with placebo in combination with trastuzumab and chemotherapy.
Evidence Level:Sensitive: C2 – Inclusion Criteria
Title:
Pembrolizumab, Trastuzumab, HER2 Positive Gastric Cancer
Excerpt:...HER2 positive advanced gastric cancer...
Evidence Level:Sensitive: C3 – Early Trials
Title:
First-line pembrolizumab and trastuzumab in HER2-positive oesophageal, gastric, or gastro-oesophageal junction cancer: an open-label, single-arm, phase 2 trial
Excerpt:pembrolizumab in combination with trastuzumab and chemotherapy in first-line HER2-positive metastatic oesophagogastric (gastric, oesophageal, or gastroesophageal junction) cancer...Pembrolizumab can be safely combined with trastuzumab and chemotherapy and has promising activity in HER2-positive metastatic oesophagogastric cancer.
DOI:10.1016/S1470-2045(20)30169-8
Evidence Level:Sensitive: C3 – Early Trials
Title:
Targeting HER2 in combination with anti-PD-1 and chemotherapy confers a significant tumor shrinkage of gastric cancer: A multi-institutional phase Ib/II trial of first-line triplet regimen (pembrolizumab, trastuzumab, chemotherapy) for HER2-positive advanced gastric cancer (AGC).
Excerpt:Pembrolizumab 200mg IV D1, Trastuzumab 6mg/kg (after 8mg/kg load) D1, Capecitabine 1000mg/m2 bid D1-14, and Cisplatin 80mg/m2 D1 every 3 weeks was selected as recommended phase II dose....First-line triplet regimen (Pembrolizumab, Trastuzumab, and Chemotherapy) confers a significant tumor shrinkage for HER2 positive AGC, regardless of PD-L1 status.
DOI:10.1200/JCO.2020.38.15_suppl.3081