Investigators are zeroing in on the stage II-IIIa non–small cell lung cancer patients most likely to benefit from adjuvant atezolizumab (Tecentriq) following resection and chemotherapy.
It seems that PD-L1 positive patients, those who undergo lobectomy, those who have nodal involvement, and those treated with all common platinum doublets, with the possible exception of cisplatin-gemcitabine, are most likely to benefit from adjuvant treatment, according to a report at the virtual 2021 World Congress on Lung Cancer.
Results come for an analysis of IMpower010, which randomized 1,005 patients equally to either best supportive care or atezolizumab every 21 days for 16 cycles following resection and chemotherapy.
The topline results, reported recently, found a 34% improvement in disease-free survival (DFS) in stage II-IIIa patients expressing PD-L1 and a 21% improvement across all patients regardless of PD-L1 expression.
It was the first positive phase 3 trial for adjuvant immunotherapy in NSCLC. Maker Hoffman-La Roche subsequently applied to the U.S. Food and Drug Administration for an indication for adjuvant treatment following surgery and platinum-based chemotherapy for NSCLC with PD-L1 expression of at least 1%.
At the WCLC meeting, investigators took a closer look at IMpower010 to gauge the impact of different surgery and chemotherapy types on outcomes.
“Improved DFS was observed with adjuvant atezolizumab” for II-IIIa disease across most stages in patients “with nodal involvement, and across most surgery resection types and chemotherapy regimens,” said lead investigator Nasser Altorki, MD, director of the division of thoracic surgery at New York Presbyterian-Weill Cornell Medical Center in New York.
Study discussant Ichiro Yoshino, MD, PhD, a thoracic surgeon at Chiba University, in Japan, expanded on the “most” part of the assertion.
“Patients who underwent lobectomy [78%] had more evident benefit. … Patients who had a pneumonectomy [16%] did not benefit from atezolizumab,” he said (DFS hazard ratio, 0.91, 95% confidence interval, 0.56-1.47).
The reasons are unclear. It could be because patients who have pneumonectomies are less tolerant of adjuvant chemotherapy, so might have not gotten complete courses, but whatever the cause, Dr. Yoshino said it’s an important finding that needs further investigation.
Also, there was no DFS benefit in the 16% of patients who received cisplatin-gemcitabine for chemotherapy instead of other platinum doublets (HR, 0.94, 95% CI, 0.56-1.57).
It might have to do with the fact that under 80% of cisplatin-gemcitabine patients completed all four cycles of chemotherapy versus completion rates of up to more than 90% with other platinum doublets. It might also, however, have something to do with the way gemcitabine works or its interaction with atezolizumab.
The issue is another one that needs “to be examined,” Dr. Yoshino said.
The trial was funded by Hoffman-La Roche. Dr. Altorki is an advisor and/or researcher for AstraZeneca, Merck, and Johnson & Johnson. Among various company ties, Dr. Yoshino is an advisor and speaker for AstraZeneca and Johnson & Johnson and a researcher for Pfizer.