Imfinzi approved as perioperative gastric cancer therapy in KOR

Improved key endpoints…”expected to reduce recurrence risk and improve long-term survival”

Immuno-oncology drug ‘Imfinzi’

AstraZeneca Korea (CEO Eldana Sauran) announced on the 23rd that Imfinzi (durvalumab) has received approval for perioperative treatment of gastric cancer in Korea.

The approved indication is for the treatment of patients with resectable gastric or gastroesophageal junction adenocarcinoma, as perioperative therapy in combination with 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) chemotherapy before and after surgery, followed by Imfinzi monotherapy as adjuvant treatment.

Under the approved regimen, Imfinzi is administered in combination with FLOT (5-fluorouracil, leucovorin, oxaliplatin, and docetaxel) for two cycles before surgery, followed by surgery. After surgery, two cycles of Imfinzi plus chemotherapy are administered, and then maintenance treatment with Imfinzi monotherapy is initiated. With this approval, Imfinzi becomes the first immuno-oncology drug approved in Korea for perioperative treatment of gastric cancer.

While surgery is the primary treatment for gastric cancer, recurrence rates have historically been high even after surgical intervention. In fact, about 40% to 60% of gastric cancer patients die from recurrence. It is also reported that among patients who experience recurrence after surgery, 50% recur within two years and 90% within five years.

This approval of Imfinzi is viewed as a new therapeutic approach that can reduce the risk of recurrence and provide survival benefits as a perioperative therapy for gastric cancer.

The approval was based on results from the global Phase III MATTERHORN study in patients with resectable gastric cancer and gastroesophageal junction adenocarcinoma. The MATTERHORN study evaluated the efficacy and safety profile of Imfinzi plus FLOT chemotherapy followed by Imfinzi monotherapy as perioperative treatment, compared with a control arm that received FLOT chemotherapy and surgery alone.

Study results confirmed that Imfinzi demonstrated clinical benefits in terms of the primary endpoint, event-free survival (EFS), as well as the secondary endpoints of overall survival (OS) and pathological complete response (pCR) rates.

Perioperative Imfinzi reduced the risk of disease progression, recurrence, or death from any cause by 29%, showing a significant improvement in EFS. At 24 months, overall survival was numerically higher in the Imfinzi perioperative treatment group at 75.7%, compared with 70.4% in the control group, although statistical significance was not established. The pCR rate was also approximately 2.7 times higher, at 19.2% in the Imfinzi group versus 7.2% in the control group.

The safety profile of perioperative Imfinzi observed in the MATTERHORN study was consistent with the known safety profiles for each individual agent.

Professor Keun-wook Lee of the Department of Hematology and Oncology at Seoul National University Bundang Hospital stated, “Gastric cancer is a type of cancer in which recurrence occurs in a substantial number of patients even when treated at a resectable stage. In particular, it has been reported that a significant number of patients with stage II–III gastric cancer experience recurrence despite receiving adjuvant therapy after surgery, rendering a new treatment strategy encompassing both pre- and post-operative settings urgently needed.”

He added, “In the MATTERHORN study, clinical benefit in terms of event-free survival and overall survival versus placebo was confirmed, and the pathologic complete response rate was also 2.7 times higher than with standard treatment, making this a clinically significant finding.”

Hyun-joo Lee, Executive Director of the Oncology Business Unit at AstraZeneca Korea, said, “Through the MATTERHORN study, we confirmed, for the first time as an immuno-oncology agent, clinical benefit in perioperative treatment for patients with resectable gastric cancer. Since Imfinzi has been approved for the treatment of gastric and gastroesophageal junction adenocarcinoma based on this study, we are deeply honored to be able to provide a meaningful new treatment option to Korean gastric cancer patients, for whom there has been a significant unmet need.”