AstraZeneca’s Imfinzi Clinches Late-Stage Victory in Aggressive Lung Cancer


Pictured: AstraZeneca sign on office building in Shanghai, China/iStock, Robert Way

AstraZeneca on Friday announced that its PD-L1 blocker Imfinzi (durvalumab) met its primary efficacy endpoints in the Phase III ADRIATIC study, showing that it can significantly improve survival in patients with limited-stage small cell lung cancer.

The pharma did not disclose specific figures in its announcement, only revealing that Imfinzi elicited a “statistically significant and clinically meaningful improvement” in the ADRIATIC’s dual primary endpoints of overall survival and progression-free survival (PFS).

In terms of safety, Imfinzi’s adverse event profile in ADRIATIC was consistent with what had been established in prior studies. No new signals of concern were detected.

Susan Galbraith, executive vice president of oncology R&D at AstraZeneca, in a statement called ADRIATIC’s results “exciting,” adding that they further establish the “transformative efficacy” of Imfinzi as a treatment for patients with extensive-stage small cell lung cancer (SCLC).

The data also point to the potential of providing a “curative-intent immunotherapy treatment to this earlier-stage setting of small cell lung cancer for the first time,” Galbraith added. AstraZeneca will present full data and findings from ADRIATIC at an upcoming medical congress and will submit them to regulatory authorities worldwide.

Afflicting around 15% of all lung cancer patients, SCLC is a relatively uncommon form of lung cancer but is generally aggressive and often recurs after treatment. According to the Cleveland Clinic, if left untreated, most patients die within months of SCLC diagnosis and less than 10% of patients survive beyond five years.

Imfinzi, a human monoclonal antibody, addresses SCLC by preventing the interaction of PD-L1 with the PD-1 and CD80 proteins. This mechanism of action allows Imfinzi to block a tumor’s ability to evade and dampen the immune system, while also boosting the body’s anti-cancer immune response.

The FDA first approved Imfinzi in 2017 for the treatment of advanced bladder cancer and the antibody has picked up several indications since. Imfinzi entered the lung cancer space in 2018, when it won the regulator’s nod for unresectable stage III non-small cell lung cancer. In March 2020, the FDA approved Imfinzi for extensive-stage SCLC.

Friday’s readout follows disappointing data from the Phase III PACIFIC-2 study, posted in November 2023. Unlike ADRIATIC, PACIFIC-2 focused on the more common but less aggressive non-small cell lung cancer and administered Imfinzi alongside chemoradiotherapy. The combination regimen did not significantly improve PFS in patients with unresectable stage III NSCLC and triggered a higher risk of infections, compared with chemoradiotherapy alone.

AstraZeneca is running several other studies under the PACIFIC clinical development program, seeking to push Imfinzi into earlier lines of lung cancer treatment.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at or

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