Pembrolizumab with platinum- and fluoropyrimidine-based chemotherapy is recommended, within its marketing authorisation, as an option for untreated locally advanced unresectable or metastatic HER2‑negative gastric or gastro-oesophageal junction adenocarcinoma in adults whose tumours express PD‑L1 with a combined positive score (CPS) of 1 or more. Pembrolizumab is only recommended if the company provides it according to the commercial arrangement.
Why the committee made these recommendations
Usual treatment for locally advanced unresectable or metastatic HER2‑negative gastric or gastro-oesophageal junction adenocarcinoma that expresses PD‑L1 with a CPS of 1 to 4 is platinum- and fluoropyrimidine-based chemotherapy (doublet chemotherapy). Treatment for advanced gastric or gastro-oesophageal junction adenocarcinoma that expresses PD‑L1 with a CPS of 5 or more is nivolumab plus doublet chemotherapy.
Clinical trial evidence shows that pembrolizumab plus doublet chemotherapy increases how long people have before their condition gets worse and how long they live compared with placebo plus doublet chemotherapy, in people whose tumours express PD‑L1 with a CPS of 1 or more.
Pembrolizumab plus doublet chemotherapy has not been directly compared in a clinical trial with nivolumab plus doublet chemotherapy. An indirect comparison suggests that it is likely to work as well as nivolumab for people whose tumours express PD‑L1 with a CPS of 5 or more.
When considering the condition's severity, and its effect on quality and length of life, the most likely cost-effectiveness estimates for pembrolizumab plus doublet chemotherapy compared with doublet chemotherapy alone are within the range that NICE considers an acceptable use of NHS resources. Pembrolizumab plus doublet chemotherapy has similar costs to nivolumab plus doublet chemotherapy. So, pembrolizumab plus doublet chemotherapy is recommended.