AstraZeneca Plc (AZN) just added another win to its Imfinzi playbook. The FDA approved the immunotherapy drug in combination with FLOT chemotherapy—that's fluorouracil, leucovorin, oxaliplatin, and docetaxel—for patients with resectable, early-stage, and locally advanced gastric and gastroesophageal junction cancers. Think of it as a one-two-three punch: Imfinzi plus chemo before surgery, then Imfinzi plus chemo after surgery, followed by Imfinzi on its own.

The approval came through FDA's Priority Review process and hinged on impressive event-free survival and overall survival data from the MATTERHORN Phase 3 trial. This is the kind of data that gets oncologists paying attention.

The Numbers That Matter

Here's what the trial showed: Patients on the Imfinzi-based perioperative regimen saw a 29% reduction in their risk of disease progression, recurrence, or death compared to those getting chemotherapy alone. The median event-free survival for the Imfinzi group hadn't even been reached yet, while the chemo-only arm clocked in at 32.8 months.

Breaking it down by timeframe, roughly 78% of Imfinzi patients were event-free at one year versus 74% in the comparison group. By two years, those numbers were 67.4% versus 58.5%. The gap widens over time, which is exactly what you want to see.

The overall survival analysis delivered similarly encouraging results. The Imfinzi combination cut the risk of death by 22% compared with chemotherapy alone. Three years out, about 69% of patients treated with Imfinzi were still alive compared to 62% in the FLOT-only group. The survival curves continued separating with longer follow-up, suggesting the benefit grows more pronounced over time. And here's a bonus: the survival advantage showed up regardless of PD-L1 status, meaning the treatment worked across a broader patient population.

Why This Matters

Gastric cancer ranks as the fifth leading cause of cancer death worldwide, with nearly one million new diagnoses annually. In the United States alone, roughly 6,500 patients with early-stage and locally advanced gastric or gastroesophageal junction cancer received drug treatment in 2024. These are tough cancers to treat, and options in the early-stage setting have been limited.

Dave Fredrickson, Executive Vice President of AstraZeneca's Oncology Haematology Business Unit, framed the approval as validation of the perioperative approach. "As the third U.S. approval for a perioperative Imfinzi-based regimen, this milestone further validates the perioperative approach and underscores our focus on bringing novel treatments to early-stage cancers where cure is the goal," he said.

That's the real game here: AstraZeneca is systematically building out Imfinzi's profile in early-stage cancers where you're still trying to cure patients, not just extend survival. This latest approval fits squarely into that strategy, giving oncologists another tool for patients who might otherwise face limited treatment options.

AstraZeneca shares were down 0.59% at $92.69 at the time of publication Tuesday, trading close to the stock's 52-week high of $93.41.