Phase 2 trial of neoadjuvant/adjuvant pembrolizumab in stage IB-IIIA NSCLC completes enrollment of 35 patients

This multi-institutional, phase 2 clinical trial has completed enrollment of 35 patients to study neoadjuvant and adjuvant pembrolizumab for stage IB, II, or IIIA non-small cell lung cancer (NSCLC). The study design involves administering two doses of pembrolizumab prior to surgery (neoadjuvant therapy) and four doses after surgery (adjuvant therapy). Pembrolizumab is an investigational immunotherapy in this setting, though it is approved for advanced lung cancer. The presumed mechanism of action is the removal of T lymphocyte inhibition by masking the PD-1 receptor. The study's hypothesis is that this masking results in the activation and proliferation of T lymphocytes with specificities against tumor-associated antigens (TILs). The researchers hypothesize that, based on the response rate to pembrolizumab in advanced lung cancer, at least 20% of lung cancers would have TIL cells with specificities against tumor-associated antigens after pembrolizumab therapy. The primary outcome is surgical feasibility rate, measured by the number of subjects who undergo surgery following neoadjuvant pembrolizumab. The study started in January 2017, reached primary completion on March 19, 2019, and results were posted on February 18, 2020. The study is led by Neal Ready, MD, PhD. The abstract does not report specific efficacy results, safety data, or limitations of the study.

For people with early-stage lung cancer (stages IB, II, or IIIA), surgery is often the first step. But what if you could boost the body's own defenses against the cancer before the operation? This study tested exactly that. Doctors gave patients a drug called pembrolizumab—a type of immunotherapy that helps the immune system recognize and attack cancer cells—both before and after surgery. The idea was to see if this approach was practical and safe. The main thing they wanted to know was simple: after getting the drug first, could patients still go through with their planned surgery? The study enrolled 35 people to find out. The researchers also wanted to look closely at what the drug does to the immune system. They focused on special immune cells called tumor-infiltrating lymphocytes (TILs), which are like the body's soldiers that can move into a tumor. The theory was that pembrolizumab might 'unmask' these cells, helping them recognize and target the cancer. While pembrolizumab is already approved for advanced lung cancer, using it around surgery for earlier stages was new. This trial was a crucial step to see if this two-part strategy—treatment before and after an operation—is something doctors can realistically offer patients.