Imfinzi Wins in Advanced Small Cell Lung Cancer Trial

AstraZeneca has reported that its PD-L1 inhibitor, Imfinzi (durvalumab), has achieved its main goals in the Phase III ADRIATIC trial, significantly enhancing the survival rate of individuals with limited-stage small cell lung cancer (SCLC). Although the company did not provide detailed data, it confirmed that Imfinzi led to a "statistically significant and clinically meaningful" improvement in both overall survival and progression-free survival (PFS), without introducing new safety concerns.

The company's executive vice president of oncology R&D, Susan Galbraith, expressed excitement over the outcome, highlighting Imfinzi's "transformative efficacy" for extensive-stage SCLC patients. She also noted the study's implications for offering a "curative-intent immunotherapy" in the early stages of SCLC, a novel approach. Full results from the ADRIATIC trial will be presented at an upcoming medical conference and submitted for regulatory review.

Small cell lung cancer, which affects approximately 15% of lung cancer patients, is a more aggressive and frequently recurring form of the disease. The Cleveland Clinic states that untreated SCLC has a grim prognosis, with most patients not surviving beyond a few months post-diagnosis and only a small fraction living more than five years.

Imfinzi, a monoclonal antibody, works by inhibiting the interaction between PD-L1 and PD-1/CD80 proteins, thereby preventing tumors from evading the immune system and enhancing the body's immune response against cancer. Initially approved by the FDA in 2017 for advanced bladder cancer, Imfinzi has since expanded its indications, including for unresectable stage III non-small cell lung cancer in 2018 and extensive-stage SCLC in March 2020.

The positive results from the ADRIATIC study contrast with the Phase III PACIFIC-2 study's findings, which reported in November 2023. The PACIFIC-2 study, focusing on non-small cell lung cancer and combining Imfinzi with chemoradiotherapy, did not show significant PFS improvements and raised concerns about increased infection risks.

AstraZeneca continues to explore Imfinzi's potential in earlier stages of lung cancer treatment through various ongoing studies under the PACIFIC program.