Pembrolizumab is a humanized IgG4 anti-programmed cell death 1 (PD-1) antibody that is widely used in various malignancies. According to the most recent European Society for Medical Oncology guidelines, pembrolizumab with or without chemotherapy is the standard first-line treatment option in stage IV non–small-cell lung cancer (NSCLC) patients without an actionable oncogenic driver. Consequently, a major group of patients was treated with this immune checkpoint inhibitor that has significantly improved survival rates for a subgroup of patients. Among these were the patients with comorbid conditions, of which clinical data on pembrolizumab treatment lacked because these patients were largely excluded from clinical trials. It resulted in discrepancies between pembrolizumab registration and its application in daily practice.


Nephrotic syndrome is one of those comorbidities associated with lung cancer of which the impact on efficacy and safety of pembrolizumab therapy is unknown. Nephrotic syndrome is characterized by severe proteinuria with hypoalbuminemia, hyperlipidemia, and peripheral edema, conditions that interfere with monoclonal antibody pharmacokinetics.