What are the results of pembrolizumab plus chemotherapy for HER2-negative gastroesophageal junction cancer?
For people with HER2-negative advanced gastric or gastroesophageal junction (GEJ) cancer, the standard first-line treatment has been chemotherapy. Adding the immunotherapy drug pembrolizumab (Keytruda) to chemotherapy is a newer approach that has been studied in large clinical trials. The results show that this combination can help people live longer and can shrink tumors more often than chemotherapy alone, though it also adds some side effects.
What the research says
The largest evidence comes from the KEYNOTE-859 trial, a global phase 3 study of over 1,500 patients with HER2-negative advanced gastric or GEJ cancer. In that trial, pembrolizumab plus chemotherapy significantly improved overall survival compared to chemotherapy plus placebo 9. A subgroup analysis of patients in China found a median overall survival of 15.9 months with pembrolizumab plus chemotherapy versus 12.2 months with chemotherapy alone 9. A separate analysis of patients in Japan reported a median overall survival of 16.8 months versus 13.3 months 11. These results are consistent with a meta-analysis that pooled multiple studies and found improved response rates and survival with pembrolizumab-containing regimens 1.
What to ask your doctor
- What is my PD-L1 combined positive score (CPS), and how does it affect whether pembrolizumab plus chemotherapy is right for me?
- What are the most common side effects of pembrolizumab plus chemotherapy, and how are they managed?
- How does this combination compare with other first-line options for HER2-negative GEJ cancer, such as zolbetuximab plus chemotherapy if I am CLDN18.2-positive?
- What is my expected overall survival and progression-free survival with this treatment based on my specific situation?
This question is drawn from common patient questions about Oncology and answered using cited medical research. We do not provide individualized advice.