Immunotherapy agents in metastatic non-small cell lung cancer (NSCLC) can result in improved quality of life and survival when compared with platinum-based chemotherapy. Novel response patterns such as pseudoprogression and hyperprogression, however, have been described and pose a challenge to treating physicians. Predictors of hyperprogressive disease (HPD) have not yet been identified. Evaluation and management by a multidisciplinary team involving medical and radiation oncologists, thoracic radiologists, and proceduralists is necessary to identify this subset of patients in a timely manner. Repeat biopsy distinguishes HPD from pseudoprogression and may eventually elucidate predictive biomarkers. We describe the epidemiology of these two phenomena, their diagnostic criteria, and their relevance for interventional pulmonologists.