FDA Clears Imfinzi as First Perioperative Immunotherapy for Resectable Gastric and GEJ Cancers | iPharmaCenter

FDA approved Imfinzi for perioperative use

The U.S. FDA approved Imfinzi (durvalumab) as the first and only perioperative immunotherapy for adults with resectable stage II–IVA gastric and gastroesophageal junction (GEJ) cancers, in combination with FLOT chemotherapy before surgery, continued with FLOT plus Imfinzi after surgery, and followed by Imfinzi monotherapy. The decision was granted Priority Review and evaluated under the FDA’s Project Orbis framework, enabling coordinated submissions with other global regulators.​

Efficacy and safety data

The approval is supported by the Phase III MATTERHORN trial, where perioperative Imfinzi plus FLOT reduced the risk of disease progression, recurrence, or death by 29% versus FLOT alone, with median event-free survival not reached in the Imfinzi arm compared with 32.8 months for placebo. Final analyses also showed a 22% reduction in the risk of death and consistent benefit irrespective of PD-L1 status, while maintaining a safety profile similar to chemotherapy alone and without increasing delays to surgery or adjuvant treatment.​

Disease burden and unmet need

Gastric and GEJ cancers remain among the most common and lethal malignancies worldwide, contributing to hundreds of thousands of deaths each year and showing rising incidence in younger adults in some regions. Even with curative-intent surgery and perioperative chemotherapy, recurrence rates are high and long-term survival remains suboptimal, highlighting the need for more effective perioperative approaches such as immunotherapy-based regimens.​

MATTERHORN trial design

MATTERHORN is a global, randomized, double-blind, placebo-controlled Phase III trial enrolling 948 patients with previously untreated, resectable stage II–IVA gastric or GEJ adenocarcinoma to receive durvalumab plus FLOT or placebo plus FLOT in the perioperative setting. Patients were treated both before and after surgery, followed by up to ten additional cycles of durvalumab or placebo monotherapy, with event-free survival as the primary endpoint and overall survival and pathologic complete response as key secondary endpoints.​

Commercial performance

The perioperative gastric and GEJ cancer indication adds to Imfinzi’s established roles in lung and hepatobiliary cancers and reinforces its status as a backbone immunotherapy in AstraZeneca’s oncology portfolio. In line with its expanding label and strong uptake across tumor types, Imfinzi ranks among the top-selling cancer drugs of 2025, generating around $4.5 billion in sales during the first nine months of the year, according to the company’s most recent financial results.​