AstraZeneca's Imfinzi (durvalumab) in combination with standard-of-care FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel) has been approved in the European Union (EU) for the treatment of adult patients with resectable, early-stage and locally advanced (Stages II, III, IVA) gastric and gastroesophageal junction (GEJ) cancers. The regimen includes two cycles of Imfinzi in combination with chemotherapy before and after surgery, followed by Imfinzi monotherapy.

The approval by the European Commission follows the positive opinion of the Committee for Medicinal Products for Human Use and is based on the positive results from the MATTERHORN Phase III trial, which were published in The New England Journal of Medicine.

Gastric cancer is the fifth leading cause of cancer death globally, with nearly one million people diagnosed each year.1 In 2024, there were roughly 15,500 drug-treated patients in the EU with early-stage and locally advanced gastric or GEJ cancer.2

Josep Tabernero, MD, PhD, head of the Medical Oncology Department at Vall d'Hebron University Hospital and director of the Vall d'Hebron Institute of Oncology (VHIO) in  Barcelona, Spain, and principal investigator in the trial, said: "Despite curative-intent surgery and chemotherapy, patients with resectable gastric and gastroesophageal cancers still face high recurrence rates and an urgent need for improved long-term survival. In MATTERHORN, nearly 70 per cent of patients were still alive three years after treatment with the durvalumab-based perioperative regimen. This EU approval brings patients the first immunotherapy regimen to extend survival in this early setting and is poised to become the new standard of care."

Dave Fredrickson, Executive Vice President, Oncology Haematology Business Unit, AstraZeneca, said: "This approval marks our third perioperative approval in Europe for an Imfinzi-based regimen, underscoring AstraZeneca's commitment to transforming outcomes in early-stage disease, where cure is possible. For patients with early gastric and gastroesophageal cancers, this immunotherapy-based regimen delivers a durable survival benefit that increases over time."

In a planned interim analysis, patients treated with the Imfinzi-based perioperative regimen showed a 29% reduction in the risk of disease progression, recurrence or death versus chemotherapy alone (based on an event-free survival [EFS] hazard ratio [HR] of 0.71; 95% confidence interval [CI] 0.58–0.86; p<0.001). Estimated median EFS was not yet reached for the Imfinzi arm versus 32.8 months for the comparator arm. An estimated 78.2% of patients treated with the Imfinzi-based perioperative regimen were event-free at one year, compared to 74.0% in the comparator arm; the estimated 24-month EFS rate was 67.4% versus 58.5%, respectively.

In the final overall survival (OS) analysis, results showed the Imfinzi and FLOT perioperative regimen demonstrated a statistically significant and clinically meaningful survival improvement, reducing the risk of death by 22% compared to chemotherapy alone (based on a HR of 0.78; 95% CI 0.63-0.96; p=0.021). An estimated 69% of patients treated with the Imfinzi-based regimen were alive at three years compared with 62% in the comparator arm. At each subsequent prespecified OS landmark, the survival curves indicated increasing separation, signaling a greater magnitude of benefit over time for the Imfinzi-based regimen. An OS benefit was observed regardless of tumour PD-L1 status. OS results from MATTERHORN were presented in a Proffered Paper session at the European Society for Medical Oncology (ESMO) Congress 2025.

The safety profile for Imfinzi and FLOT chemotherapy was consistent with the known profiles of each medicine, and the percentage of patients that completed surgery was similar compared to chemotherapy alone. Grade 3 or higher adverse events due to any cause were similar between the two arms (71.6% for Imfinzi and FLOT arm; 71.2% for comparator arm).

Imfinzi and FLOT chemotherapy is approved in the US and other countries based on the MATTERHORN results. Regulatory applications are currently under review in Japan and several other countries for this indication.