AstraZeneca's Imfinzi Shows Promise in Early-Stage Stomach Cancer Treatment

AstraZeneca has announced positive results from its phase 3 Matterhorn trial, investigating the use of its immunotherapy drug Imfinzi (durvalumab) in early-stage gastric and gastroesophageal junction cancers. The study, which evaluated Imfinzi in combination with chemotherapy as a perioperative treatment, has met its primary endpoint, marking a significant advancement in the field of oncology.

Matterhorn Trial Highlights

The Matterhorn trial assessed Imfinzi in combination with FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel) in patients with resectable, early-stage gastric and gastroesophageal junction cancers. The treatment regimen was administered both before and after surgery, followed by Imfinzi monotherapy for several additional cycles.

Key findings from the trial include:

• A statistically significant reduction in the risk of disease recurrence, worsening, or death when Imfinzi was added to chemotherapy.
• An improvement in pathological complete response (pCR) rates, with 19% of patients in the Imfinzi arm achieving pCR compared to 7% in the chemotherapy-only arm.
• A "strong trend" suggesting a potential overall survival benefit, although final analysis is still pending.

Dr. Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer at AstraZeneca, emphasized the significance of these results, stating, "Matterhorn is now the first phase 3 trial of an immunotherapy to show a statistically significant improvement in event-free survival in this cancer setting."

Implications for Standard of Care

The positive outcomes from the Matterhorn trial could potentially transform the standard of care for patients with early-stage gastric and gastroesophageal junction cancers. AstraZeneca is preparing to engage in discussions with global regulatory authorities, including the FDA, regarding a potential new indication for Imfinzi in this setting.

The company's spokesperson expressed eagerness to bring this regimen to patients, highlighting its potential to significantly impact treatment outcomes. However, the perioperative approach has raised some concerns among medical professionals, particularly regarding the risk of overtreatment and the need for separate efficacy data for each phase of treatment.

Regulatory Considerations and Future Directions

As AstraZeneca moves forward with its plans to seek regulatory approval for Imfinzi in early-stage stomach cancer, the company will need to address potential concerns raised by previous advisory committee meetings. A recent FDA panel unanimously called for future trials in resectable non-small cell lung cancer to include assessments of the contributions of each treatment phase in perioperative settings.

The company plans to present detailed results from the Matterhorn trial at upcoming medical meetings, which will provide the scientific community with a more comprehensive understanding of Imfinzi's efficacy and safety profile in this new indication. These data will be crucial in shaping future treatment guidelines and regulatory decisions.