AstraZeneca Reports Positive Phase 3 Results for Imfinzi in Gastric Cancer

AstraZeneca (AZ) has unveiled promising outcomes from a late-stage clinical trial involving its Imfinzi (durvalumab)-based perioperative treatment regimen for gastric cancer. The phase 3 MATTERHORN study has been assessing the effectiveness of Imfinzi when combined with a standard chemotherapy regimen consisting of fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) administered prior to surgical intervention. After surgery, the treatment continues with Imfinzi plus chemotherapy, followed by Imfinzi monotherapy for patients diagnosed with resectable, early-stage, and locally advanced gastric and gastroesophageal junction cancers.

The results of the trial indicate that the Imfinzi-based regimen has led to a significant and meaningful enhancement in event-free survival (EFS), the primary endpoint, when compared to perioperative chemotherapy alone. Additionally, there was a noticeable favorable trend regarding the secondary endpoint of overall survival, which will undergo formal evaluation at the trial's final analysis. The safety profiles of both Imfinzi and the FLOT chemotherapy regimen were consistent with their established profiles, with no new safety concerns emerging.

Gastric cancer ranks as the fifth leading cause of cancer-related fatalities worldwide, accounting for nearly one million new cases annually. Despite surgical procedures intended to cure and treatment with neoadjuvant or adjuvant chemotherapy, approximately one in four individuals with resectable gastric cancer experiences recurrent disease within a year, and another one in four does not survive beyond two years.

Imfinzi, AZ’s immunotherapy, targets the PD-L1 protein, which cancer cells exploit to circumvent the immune system. The drug is already approved for use in lung cancer, biliary tract cancer, endometrial cancer, and hepatocellular carcinoma. Cristian Massacesi, AZ’s chief medical officer and oncology chief development officer, remarked on the significance of the trial, stating, "MATTERHORN represents the first phase 3 study of immunotherapy to demonstrate a statistically significant improvement in EFS for patients with resectable gastric and gastroesophageal junction cancers."

He emphasized that this perioperative strategy with Imfinzi highlights AZ's commitment to addressing earlier stages of cancer, where innovative therapies can profoundly impact patients' lives. The trial's data is set to be presented at an upcoming medical forum and will be shared with regulatory authorities worldwide, according to AZ.

These findings follow less than a month after AZ revealed positive phase 3 outcomes for an Imfinzi perioperative regimen for muscle-invasive bladder cancer at the American Society of Clinical Oncology Genitourinary Cancers Symposium. This sequence of successful trials underscores AZ’s ongoing dedication to advancing cancer treatment through innovative therapeutic approaches, addressing various cancer types, and improving patient survival rates.

The MATTERHORN study adds valuable insights into the potential benefits of combining immunotherapy with established chemotherapy regimens in the perioperative treatment landscape for gastric cancer. As regulatory bodies review the data, healthcare providers and patients alike anticipate the prospect of new treatment options that may offer improved outcomes for those battling this challenging disease.