Topline MATTERHORN findings
- Imfinzi plus FLOT reduced the risk of death by 22% versus chemotherapy alone (HR 0.78; P=0.021).
- Three-year overall survival reached 69% with the Imfinzi regimen compared to 62% with FLOT alone.
- Pathologic response strongly correlated with improved event-free survival across all response categories.
- The survival benefit was consistent regardless of PD-L1 status or lymph node involvement.
- Imfinzi is the first immunotherapy to show statistically significant EFS improvement in resectable gastric and GEJ cancers.
The FDA has approved AstraZeneca’s Imfinzi (durvalumab) in combination with standard-of-care FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel) for the treatment of adult patients with resectable, early-stage and locally advanced (Stages II, III, IVA) gastric and gastroesophageal junction (GEJ) cancers.1
The approved regimen includes:
- Neoadjuvant Imfinzi in combination with chemotherapy prior to surgery
- Adjuvant Imfinzi in combination with chemotherapy
- Imfinzi monotherapy
In a press release, Dave Fredrickson, executive vice president, oncology hematology business unit, AstraZeneca, said: “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. As the third US approval for a perioperative Imfinzi-based regimen, this milestone further validates the perioperative approach and underscores our focus on bringing novel treatments to early-stage cancers where cure is the goal.”
Approval based on positive Phase III MATTERHORN data
Imfinzi’s approval is based on positive data from the Phase III MATTERHORN clinical trial (NCT04592913). Results shared earlier in October demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) compared to chemotherapy alone.2
Additional findings from the final OS analysis showed:
- Imfinzi plus FLOT perioperative regimen reduced the risk of death by 22% versus chemotherapy alone (HR 0.78; 95% CI: 0.63–0.96; P=0.021).
- Median OS was not reached in either treatment arm.
- At three years, estimated survival was 69% with the Imfinzi-based regimen compared with 62% for FLOT alone.
In the press release, Yelena Y. Janjigian, MD, chief attending physician of the Gastrointestinal Medical Oncology Service, Memorial Sloan Kettering Cancer Center (MSK), New York and principal investigator in the MATTERHORN trial, added: “Today’s approval marks the first immunotherapy regimen approved in the neoadjuvant setting for gastric and gastroesophageal junction cancers—with durvalumab demonstrating a clear overall survival benefit and opening an entirely new chapter in the treatment of early-stage disease. Nearly seven in 10 patients were alive at three years following treatment with the durvalumab-based perioperative regimen. This survival benefit, observed regardless of PD-L1 status, establishes a new standard of care in this curative-intent setting.”
