This designation is granted for treatments that could significantly improve upon existing options.
The FDA’s decision is expected by the fourth quarter of 2025, in line with the Prescription Drug User Fee Act date.
AstraZeneca Oncology Haematology R&D executive vice-president Susan Galbraith said: “This priority review reinforces the potential for a perioperative approach with Imfinzi to transform care for patients with early gastric and gastroesophageal junction cancers, who frequently face disease recurrence or progression even after curative-intent surgery and perioperative chemotherapy.
“This novel treatment is the only immunotherapy-based regimen to show a statistically significant reduction in the risk of progression, recurrence or death in this setting, and if approved, is poised to change the clinical paradigm.”
The sBLA submission is supported by results from the MATTERHORN Phase III trial, which were highlighted in the Plenary Session at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting.
This double-blind, randomised, placebo-controlled, multi-centre, international trial is evaluating Imfinzi as perioperative treatment for resectable Stage II-IVA gastric and GEJ cancers.
Additionally, Imfinzi received breakthrough therapy designation (BTD) from the FDA, a status that expedites the development and review process for new medications aimed at treating serious conditions and fulfilling unmet medical needs.
Regulatory applications are currently being reviewed in the EU, Japan and several other nations based on the MATTERHORN data.