Imfinzi is the first immunotherapy approved for perioperative use to treat gastric and gastroesophageal junction cancers.
AstraZeneca’s Imfinzi can now be used to treat patients with gastric and gastroesophageal junction cancers as part of a chemotherapy combination, adding another indication for the blockbuster PD-L1 inhibitor.
The FDA on Tuesday cleared Imfinzi for resectable tumors stages II through IVA, suggesting early-stage or locally advanced disease. In this indication, Imfinzi should be given with fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) as part of a perioperative schedule. According to AstraZeneca’s news release on Tuesday, Imfinzi is the first perioperative immunotherapy approved for gastric and gastroesophageal junction (GEJ) cancer.
Data from the Phase III MATTERHORN study supported the regulator’s decision. A readout in June showed that Imfinzi plus FLOT cut the risk of disease progression, recurrence or death by 29% versus chemotherapy alone. At 1 year, 78.2% of patients on the Imfinzi-based regimen were event-free, versus 74% of comparators on chemotherapy.
Overall survival figures were immature at the time, but AstraZeneca on Thursday revealed the outcomes of the final analysis. Compared with chemotherapy controls, the Imfinzi schedule elicited a 22% decrease in the risk of death. At three years, around 69% of Imfinzi-treated patients remained alive, as opposed to 62% in the comparator arm.
As for safety, MATTERHORN found no new signals of concern. Side effects of Imfinzi and of the FLOT regimen were consistent with what had been established in prior studies.
In a statement alongside the company’s press release, Dave Fredrickson, executive vice president of AstraZeneca’s Oncology Hematology Business Unit, said this latest approval for Imfinzi “ushers in a new clinical paradigm” for early gastric and GEJ cancers. The Imfinzi plus FLOT combo, he added, delivers a “durable survival benefit that increases over time.”
Designed to prevent tumor cells from suppressing the body’s anticancer response, Imfinzi was first approved in 2017 for advanced bladder cancer. The drug has since picked up other indications, including breast cancer and non-small cell lung cancer (NSCLC). Tuesday’s approval is its first foray into stomach cancer.
Imfinzi has been on an impressive run of late. In March, the FDA cleared the drug for muscle-invasive bladder cancer, and in 2024, Imfinzi notched three regulatory wins: mismatch repair-deficient endometrial cancer in June, perioperative use in NSCLC in August and limited-stage small cell lung cancer in December.
AstraZeneca in its year-end report in February named Imfinzi as one of its main growth drivers. Last year, the drug earned more than $4.7 billion. Imfinzi is on track to surpass this in 2025, earning over $4.3 billion in the first nine months of the year worldwide.
