Cases included in the review involved advanced non–small cell lung cancer (NSCLC) patients with a median age of 66 years who were treated with nivolumab or pembrolizumab at the Mayo Clinic from January 2010 to April 2017. Most (91%) were white, 4.5% were African American, 1.9% were Asian, 0.6% were native Hawaiian/Pacific Islander, and 1.9% were other ethnicities. Slightly more than half (53%) were men, and diagnoses included adenocarcinoma (69%), squamous disease (29%) and other (3%). Half had one prior line of chemotherapy, 22% had two prior lines, and 10% had three or more prior lines. The majority (72%) had Eastern Cooperative Oncology Group performance status of 1 or 2, and 34% had CNS disease.
Pembrolizumab was given intravenously at a dose of 2 mg/kg every 21 days (11 patients), and nivolumab was given intravenously at a dose of 3 mg/kg every 14 days (146 patients). Clinical response was assessed every 8-12 weeks by CT of the chest, abdomen and pelvis, and also – in some cases – by brain MRI.
The findings are notable because, although combination chemotherapy with a platinum-based doublet has, for the last decade, been the backbone of initial systemic therapy for patients whose tumor does not have driver mutations, monoclonal antibodies targeting PD-1 or its ligand PD-L1 have shown improvements in progression-free survival and overall survival in certain patients with metastatic or locally advanced lung cancer, the investigators explained.
Prior studies in melanoma patients treated with immunotherapy targeting the cytotoxic T-lymphocyte antigen 4 pathway and PD-1/PD-L1 pathways have identified predictive or prognostic hematological markers of outcomes. However, data with respect to hematologic markers in lung cancer are sparse, and given the high cost, significant immune-related side effects, and rapidly expanding number of indications for immunotherapy in NSCLC, there is a need for reliable biomarkers to help predict response and outcomes, they said.