IMFINZI® Regimen Shows Improved Survival in Early-Stage Gastric and GEJ Cancers
AstraZeneca’s innovative perioperative treatment combining IMFINZI® (durvalumab) with standard chemotherapy has shown significant improvements in survival outcomes for patients with resectable, early-stage gastric and gastroesophageal junction (GEJ) cancers. In the Phase III MATTERHORN trial, this combination treatment demonstrated a statistically significant and clinically meaningful improvement in event-free survival (EFS), the primary endpoint of the study.
The MATTERHORN trial investigated the effects of combining IMFINZI, an immune checkpoint inhibitor, with standard chemotherapy (FLOT: fluorouracil, leucovorin, oxaliplatin, and docetaxel) in patients with Stage II, III, and IVA gastric and GEJ cancers. The patients received a perioperative treatment regimen where IMFINZI was administered in combination with chemotherapy before surgery, followed by adjuvant IMFINZI and chemotherapy post-surgery, and then IMFINZI alone as maintenance therapy. This treatment regimen was compared to perioperative chemotherapy alone to evaluate its potential benefits.
The results of the trial were highly promising. The treatment regimen with IMFINZI demonstrated a statistically significant improvement in event-free survival, meaning that patients in the IMFINZI-based group experienced a longer period without cancer recurrence compared to those who received chemotherapy alone. In addition, while the trial’s interim analysis showed a strong trend favoring the IMFINZI regimen for overall survival (OS), formal assessment of OS will be made at the final analysis.
Gastric Cancer: A Major Global Health Concern
Gastric cancer is one of the leading causes of cancer-related deaths worldwide. According to recent estimates, it is the fifth most common cancer globally, with nearly one million people diagnosed annually. In regions such as the United States, the European Union (EU), and Japan, approximately 43,000 patients are treated for early-stage and locally advanced gastric or GEJ cancers in 2024. With projections estimating that 62,000 new patients will be diagnosed by 2030, the need for effective treatment options remains urgent.
Yelena Y. Janjigian, M.D., the Chief Attending Physician of the Gastrointestinal Medical Oncology Service at Memorial Sloan Kettering Cancer Center and principal investigator of the MATTERHORN trial, emphasized the significance of these results. “Despite receiving curative-intent chemotherapy and surgery, many gastric cancer patients face disease recurrence and poor prognosis. The data from MATTERHORN are exciting as they show that a durvalumab-based perioperative regimen can meaningfully improve patient outcomes, including reducing the risk of cancer recurrence,” she said.
The MATTERHORN Trial: Key Findings
The MATTERHORN trial is the first Phase III study to demonstrate a statistically significant improvement in event-free survival for patients with resectable gastric and GEJ cancers when treated with an immunotherapy-based regimen. According to Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer at AstraZeneca, the results highlight the potential of IMFINZI to transform the treatment landscape for gastric cancer. “MATTERHORN underscores our commitment to moving into earlier stages of cancer treatment, where novel therapies can have the greatest impact on patients’ lives,” he stated.
In addition to the primary endpoint of event-free survival, a key secondary endpoint showed an impressive result in pathologic complete response (pCR). The combination of IMFINZI and chemotherapy more than doubled the pCR rate compared to chemotherapy alone (19% vs. 7%), with a highly statistically significant result (p<0.00001). These findings suggest that the combination therapy not only improves survival but also enhances the likelihood of patients achieving complete remission after treatment.
Safety Profile Consistent with Expectations
The safety profile of the IMFINZI and FLOT chemotherapy combination in the MATTERHORN trial was consistent with previously known data for both treatments, with no new safety signals identified. The combination therapy did not present any unexpected adverse effects, and the side effects were manageable using established protocols. As with all immune checkpoint inhibitors, patients were closely monitored for immune-mediated reactions, and appropriate interventions were made when necessary.
Looking Ahead: Next Steps
The MATTERHORN trial continues to follow patients for overall survival, which will be formally assessed at the final analysis. The results will contribute to further understanding of how this IMFINZI-based treatment can improve long-term survival outcomes for patients with gastric and GEJ cancers.
The findings from this trial will be presented at an upcoming medical meeting, and the data will be shared with global regulatory authorities for potential approval. If approved, this treatment regimen could offer a promising new option for patients with early-stage gastric and GEJ cancers, offering hope for improved survival and quality of life.
