the overall patient population and in those with a PD-L1 TPS of 50% or higher.
The trial enrolled a total of 1177 patients who were randomized 1:1 to receive either intravenous (IV) pembrolizumab at a dose of 200 mg every 3 weeks for 1 year or IV placebo every 3 weeks for 1 year. Other exclusion criteria included having received a live vaccine within 30 days before their first infusion, having a history of human immunodeficiency virus, chronic use of immunosuppressive agents, a history of interstitial lung disease, active autoimmune disease that requires systemic treatment in the past 2 years, and a history of a hematologic or primary solid tumor, among others.
If patients had evidence of disease at the time of examination and/or baseline radiological assessment, received more than 4 cycles of adjuvant treatment, or received prior PD-1, PD-1/2, anti-CD137, CTLA-4 modulators, or other immune-modulating drugs, they were excluded. Patients also needed to have a tumor sample obtained at the time of resection to undergo assessment for PD-L1 expression per immunohistochemistry. They could not have severe comorbidities, nor prior or planned neoadjuvant or adjuvant radiotherapy and/or neoadjuvant chemotherapy for their current malignancy. 2 Patients had to have an ECOG performance status of 0 or 1 and acceptable organ function. KEYNOTE-091 enrolled patients with a pathological diagnosis of NSCLC that was Union for International Cancer Control v7 stage IB, II to IIIA following complete resection with margins that proved to be microscopically free of disease. “We are encouraged by these results supporting the potential role of in stage IB to IIIA NSCLC.” “ has become foundational in the treatment of metastatic NSCLC and we continue to advance research to explore its potential to help fight cancer earlier,” Roy Baynes, MD, PhD, senior vice president and head of global clinical development, as well as chief medical officer of Merck Research Laboratories, stated in a press release. Data from the trial are anticipated to read out at an upcoming medical conference, and to also be submitted to regulatory authorities for further discussion. KEYNOTE-091 is the first positive study for adjuvant pembrolizumab in patients with stage IB to IIIA NSCLC, according to Merck.