AstraZeneca immunotherapy extends survival by two years in rarer type of lung cancer

AstraZeneca’s immunotherapy Imfinzi helped people in the early stages of a type of lung cancer live 23 months longer than those who received just chemoradiotherapy, according to clinical trial data released Sunday. The finding should help the U.K.-based pharmaceutical company expand the drug’s use in the disease.

Researchers in the study, called Adriatic, used Imfinzi as “consolidation” therapy following an initial round of chemotherapy and radiation in people with small cell lung cancer that had not spread beyond one side of the chest, called limited stage disease. The goal of treatment was to help stave off relapse.

Radiation therapy to prevent the spread of cancer to the brain is currently the standard of care. But experts commenting on the study as it was presented at the American Society of Clinical Oncology meeting in Chicago said those protocols were introduced in the 1980s.

“This is the first trial that shows adding an immune checkpoint inhibitor as maintenance actually has benefit, which I think is very important,” said Erminia Massarelli, co-director of the lung cancer and thoracic oncology program at City of Hope in California, in an interview. 

If regulators follow through with an approval, Imfinzi’s use in treating small cell lung cancer would expand from “extensive-stage” disease, when tumors are found in a second lung and other tissues in the body.

In that setting, Imfinzi competes with Roche’s immunotherapy Tecentriq. Amgen’s new dual-acting drug Imdelltra recently gained approval in extensive-stage disease after chemotherapy, and that drugmaker has plans to expand use, including a head-to-head trial against Imfinzi.

The data in limited-stage disease presented at ASCO came from an interim analysis of 264 people treated with Imfinzi and 266 who received a placebo. A little more than half of study participants in both groups also had received radiotherapy to prevent the spread of disease to the brain.

Adding Imfinzi reduced the risk of death by 27% versus placebo, researchers found. People who received AstraZeneca’s drug lived a median of 56 months after entering the trial, compared with 33 months among those given placebo.

Imfinzi also helped prevent worsening disease, reducing the risk of cancer progression by 24%. Median progression-free survival among those on Imfinzi was 17 months, about eight months longer than the median figure for the placebo group.

Lauren Byers, thoracic section chief at MD Anderson Cancer Center, called Adriatic “a landmark study [that] provides a new standard of care.” Byers was not involved in the study, but has consulted with AstraZeneca.

“This had an improvement of overall survival of two years,” Byers said. “This is in contrast to many clinical trials in small cell lung cancer where the benefit may only be measured in months.”

The trial included a separate group of patients who received radiation therapy, Imfinzi and another AstraZeneca immunotherapy called Imjudo. Because of the trial’s design, researchers haven’t yet been able to calculate whether people in that group lived longer or went longer without their cancer returning.

Imfinzi brought in $4.2 billion in sales last year, making it AstraZeneca’s third-biggest seller. It is one of many cancer treatments the company has marked for expansion as it seeks to achieve $80 billion in annual sales by 2030.

Editor’s note: This story has been updated with additional physician commentary.