EU Approves Imfinzi Gastric Cancer Treatment as Perioperative Immunotherapy
Imfinzi gastric cancer treatment has received European Commission approval for adults with resectable, early-stage and locally advanced (Stages II, III, IVA) gastric and gastroesophageal junction (GEJ) cancers. AstraZeneca’s Imfinzi (durvalumab), a PD-L1 inhibitor, combined with FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel), marks the first perioperative immunotherapy regimen: two cycles before and after surgery, followed by Imfinzi monotherapy. This builds on MATTERHORN Phase III trial results published in the New England Journal of Medicine, showing a 29% reduction in risk of disease progression, recurrence, or death (event-free survival [EFS] HR 0.71; 95% CI 0.58–0.86; p<0.001) and 22% mortality risk reduction (overall survival [OS] HR 0.78; 95% CI 0.63-0.96; p=0.021), with 69% of Imfinzi-treated patients alive at three years versus 62% on chemotherapy alone.
Survival Gains Amplify Over Time
The MATTERHORN trial demonstrates Imfinzi gastric cancer treatment efficacy, with statistically significant EFS and OS improvements widening over time via survival curve separation at key landmarks. Median EFS was not reached in the Imfinzi arm versus 32.8 months for FLOT alone; 78.2% were event-free at one year (versus 74.0%) and 67.4% at 24 months (versus 58.5%). OS benefits held regardless of PD-L1 status, countering high relapse rates—one in four patients recur within a year post-surgery. Presented at ESMO Congress 2025, these findings target ~15,500 EU patients yearly, elevating perioperative Imfinzi as a potential standard.
Robust Trial Design Drives Approval
MATTERHORN randomized 948 patients across 176 centers in 20 countries to Imfinzi (1500 mg) plus FLOT or placebo plus FLOT for two neoadjuvant cycles, then up to 10 adjuvant Imfinzi monotherapy cycles. Primary endpoint EFS measured time to RECIST v1.1 progression, recurrence, or death; secondaries included pathologic complete response and OS. Safety matched profiles: 71.6% Grade 3+ adverse events in Imfinzi arm versus 71.2% comparator, with equivalent surgical rates. Amid gastric cancer’s one million annual diagnoses and 660,000 deaths globally, this supported the Committee for Medicinal Products for Human Use recommendation.
Reshaping Reimbursement and Access
Imfinzi will potentially reshape reimbursement decisions by offering curative-intent immunotherapy where five-year survival lags below 50%. EFS/OS risk reductions (29%/22%) support premium pricing for 15,500 EU patients, advancing updates to treatment algorithms due to prolonged event-free survival. As AstraZeneca’s third EU perioperative Imfinzi nod, it boosts immuno-oncology in GI cancers, aiding HTA submissions on long-term gains.
