For patients with operable non-small cell lung cancer (NSCLC), pre-surgical "neoadjuvant" treatment with an immune checkpoint inhibitor was well tolerated and, in many cases, caused significant tumor cell death in a large, multicenter clinical trial involving investigators at Dana-Farber Cancer Institute, Brigham and Women's Hospital, and nine other research centers. Interim results of the trial will be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting.

Participants in the trial had surgically removable NSCLC ranging from stage IB to IIIB. Patients were treated with two cycles of atezolizumab, which blocks the PD-L1 immune checkpoint protein on some , then had surgery to remove the lung cancer tissue.

The results to be reported today involve the first 101 participants in the trial, 90 of whom had surgery following treatment with atezolizumab. Excluding eight patients whose cancers had driver mutations, 15 participants (representing 18% of the total) had a major pathologic response to the treatment, defined as 10% or fewer viable cancer cells detected in the surgically removed tumor tissue. Four patients had a pathological complete response, an absence of residual cancer following the neoadjuvant therapy. Seventy-two of the participants had stable disease, and four had their disease progress.

Treatment related rated as Grade 3 or 4—considered severe or urgent—occurred in six of the 90 participants.

"Immune checkpoint therapy is included as a standard of care for patients with advanced (metastatic) lung cancer, and this study suggests that it may also have benefit in early stage, operable lung cancer," said the study's lead author, David Kwiatkowski, MD, Ph.D., senior physician at Dana-Farber/Brigham and Women's Cancer Center.

Researchers will present Abstract #8503 at the Lung Cancer—Non-Small Cell Local-Regional/Small Cell/Other Thoracic Cancers session on Saturday, June 1 at 2:15 p.m. CT in Hall D2 of the McCormick Place.