AstraZeneca's Imfinzi Breaks New Ground in Early-Stage Stomach Cancer Treatment

AstraZeneca's immunotherapy drug Imfinzi (durvalumab) has received FDA approval for the treatment of early-stage gastric and gastroesophageal junction (GEJ) cancers, marking a significant advancement in perioperative care for these patients. This latest approval establishes Imfinzi as the first immunotherapy to be used both before and after surgery in combination with chemotherapy for this patient population.

Landmark Approval for Perioperative Use

The FDA's decision allows Imfinzi to be used alongside the standard FLOT chemotherapy regimen (fluorouracil, leucovorin, oxaliplatin, and docetaxel) in adult patients with resectable, early-stage, and locally advanced gastric and GEJ cancers. The approval encompasses a comprehensive treatment approach:

1. Pre-surgery: Imfinzi combined with FLOT chemotherapy
2. Post-surgery: Imfinzi with FLOT chemotherapy
3. Maintenance: Imfinzi monotherapy

Dave Fredrickson, Executive Vice President and head of AstraZeneca's oncology hematology business unit, highlighted the significance of this approval, stating, "This approval ushers in a new clinical paradigm for patients with early gastric and gastroesophageal junction cancers, with Imfinzi plus FLOT delivering a durable survival benefit that increases over time."

Matterhorn Trial: Pivotal Data Supporting Approval

The FDA's decision was based on results from the phase 3 Matterhorn trial, which involved 948 patients with stage 2 to 4a resectable gastric and GEJ cancers. Key findings from the trial include:

• 29% reduction in the risk of disease recurrence, progression, or death compared to FLOT chemotherapy alone
• First phase 3 trial of an immunotherapy to show statistically significant event-free survival improvement in early-stage gastric cancer
• 69% of Imfinzi-treated patients remained alive after three years, compared to 62% in the FLOT-only arm
• 22% reduction in the risk of death compared to chemotherapy alone, regardless of PD-L1 status

Dr. Josep Tabernero, principal investigator of the Matterhorn trial, emphasized the transformative nature of these results, particularly given the poor long-term prognosis and high recurrence rates associated with these cancers despite curative-intent surgery and chemotherapy.

Expanding Imfinzi's Perioperative Portfolio

This latest approval further solidifies Imfinzi's position in the perioperative treatment landscape. The drug had previously received perioperative indications for:

1. Early-stage resectable non-small cell lung cancer (NSCLC)
2. Muscle-invasive bladder cancer (MIBC)

The success in gastric and GEJ cancers represents Imfinzi's third perioperative approval, underscoring AstraZeneca's focus on developing treatments for early-stage cancers where cure is the primary goal.

As the pharmaceutical industry continues to advance perioperative care, Imfinzi's latest milestone not only provides a new treatment option for patients with early-stage gastric and GEJ cancers but also validates the perioperative approach in oncology. With its expanding indications and strong financial performance, Imfinzi remains a key player in AstraZeneca's oncology portfolio, having generated $1.6 billion in sales during the third quarter of 2025.