AstraZeneca's Imfinzi Breaks New Ground in Gastric Cancer Treatment

AstraZeneca has secured a significant victory in the field of oncology with the FDA's approval of Imfinzi for the treatment of gastric and gastroesophageal junction (GEJ) cancers. This landmark decision marks Imfinzi as the first immunotherapy approved for perioperative use in these types of cancers, potentially revolutionizing treatment approaches for patients with resectable tumors in stages II through IVA.

Imfinzi's Expanding Portfolio

The recent FDA clearance adds to Imfinzi's growing list of indications, which already includes treatments for bladder cancer, breast cancer, and non-small cell lung cancer (NSCLC). This PD-L1 inhibitor, first approved in 2017, has been on an impressive streak of regulatory wins. In the past year alone, Imfinzi has gained approvals for muscle-invasive bladder cancer, mismatch repair-deficient endometrial cancer, perioperative use in NSCLC, and limited-stage small cell lung cancer.

MATTERHORN Study: Pivotal Data Supporting Approval

The FDA's decision was based on compelling data from the Phase III MATTERHORN study. Key findings include:

• A 29% reduction in the risk of disease progression, recurrence, or death when Imfinzi was combined with FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel) compared to chemotherapy alone.
• At the one-year mark, 78.2% of patients on the Imfinzi-based regimen were event-free, versus 74% in the chemotherapy-only group.
• Final analysis revealed a 22% decrease in the risk of death with the Imfinzi schedule.
• Three-year survival rates showed 69% of Imfinzi-treated patients remained alive, compared to 62% in the control arm.

Importantly, the safety profile of Imfinzi combined with FLOT was consistent with previous studies, with no new concerns identified.

Financial Impact and Future Outlook

Imfinzi has been a significant growth driver for AstraZeneca, with the drug earning over $4.7 billion in 2024. The momentum continues in 2025, with earnings exceeding $4.3 billion in just the first nine months. This latest approval is poised to further bolster Imfinzi's market position and financial performance.

Dave Fredrickson, executive vice president of AstraZeneca's Oncology Hematology Business Unit, emphasized the significance of this approval, stating it "ushers in a new clinical paradigm" for early gastric and GEJ cancers. The combination of Imfinzi with FLOT chemotherapy offers patients a "durable survival benefit that increases over time," potentially setting a new standard in gastric cancer treatment.

As Imfinzi continues to expand its indications and demonstrate efficacy across various cancer types, it solidifies AstraZeneca's position as a leader in oncology therapeutics. The pharmaceutical industry will be watching closely to see how this latest approval impacts patient outcomes and shapes future treatment strategies in gastric and GEJ cancers.