FDA Accelerates Review of Durvalumab for Early-Stage Gastric Cancers

The U.S. Food and Drug Administration (FDA) has expedited the review process for durvalumab, a PD-L1 blocking antibody developed by AstraZeneca, for the treatment of patients with resectable early-stage gastric and gastroesophageal junction (G/GEJ) cancers. This decision comes on the heels of promising results from the phase 3 MATTERHORN trial, which demonstrated significant improvements in event-free survival (EFS) when durvalumab was used in combination with chemotherapy.

The MATTERHORN trial, a multinational, double-blind, randomized study, involved a comparison between the standard chemotherapy regimen, known as FLOT (fluorouracil, leucovorin, oxaliplatin, and docetaxel), and the same regimen combined with durvalumab. The trial's results revealed that patients receiving durvalumab had a 2-year EFS rate of 67.4%, compared to 58.5% in the placebo group, indicating a statistically significant reduction in the risk of disease progression or recurrence (hazard ratio 0.71, P < .001).

Susan Galbraith, Executive Vice President of Oncology Hematology Research and Development at AstraZeneca, emphasized the groundbreaking potential of this treatment, stating, "This priority review reinforces the potential for a perioperative approach with durvalumab to transform care for patients with early gastric and gastroesophageal junction cancers, who frequently face disease recurrence or progression even after curative-intent surgery and perioperative chemotherapy."

Gastric cancer poses a significant challenge in oncology, with high rates of recurrence following surgical intervention. According to the American Cancer Society, approximately 26,000 new cases of gastric cancer are diagnosed annually in the United States, with a majority presenting at advanced stages. The urgency for effective treatment strategies is underscored by data indicating that nearly 25% of patients undergoing surgery with curative intent experience recurrence within one year.

The MATTERHORN trial was designed to evaluate the efficacy of durvalumab in this high-risk population. A total of 948 patients were enrolled, randomly assigned to receive either durvalumab or placebo every four weeks alongside FLOT therapy. In addition to EFS, secondary endpoints included overall survival (OS) and pathological complete response (pCR). The trial's findings demonstrated an OS rate of 75.7% in the durvalumab group versus 70.4% in the placebo cohort, further supporting the potential benefits of this immunotherapy in treating G/GEJ cancers.

Durvalumab is already an approved treatment option for various cancers, including unresectable non-small cell lung cancer and muscle-invasive bladder cancer. The FDA's designation of priority review and breakthrough therapy for this indication highlights the growing recognition of durvalumab's efficacy across multiple oncological settings.

Experts in oncology are optimistic about the implications of these findings. Dr. Yelena Janjigian, a leading oncologist involved in the MATTERHORN trial, noted, "The addition of durvalumab represents a significant advancement in the treatment arsenal against gastric cancer, offering hope for improved outcomes in a population that has limited therapeutic options."

As the FDA's review continues, stakeholders in the healthcare community—including clinicians, researchers, and patients—are encouraged to stay informed about the developments surrounding durvalumab. Given the positive trajectory of research and clinical trials, there is cautious optimism that this treatment could soon redefine the standard of care for patients diagnosed with resectable early-stage gastric and gastroesophageal junction cancers. The ongoing studies and subsequent approvals may lead to expanded indications for durvalumab in the future, enhancing therapeutic options for patients facing this formidable disease.

This expedited review also aligns with the FDA's commitment to accelerating the availability of innovative therapies for serious conditions, as stated in their 2020 report on breakthrough therapies. The MATTERHORN trial results underscore the vital need for continued research and investment in cancer therapies, particularly for diseases with high mortality rates and limited treatment modalities. As the medical community awaits the FDA's final decision, the focus remains on improving patient outcomes and reducing the burden of gastric cancer worldwide.