PDCD1 and neoplasm: 31 individuals with r/r cHL disease were taken in the study. The patient's response to the treatment was evaluated after 12 weeks and after that every 8 weeks. Safety and the percentage of complete remission (CR) served as the main objectives. In this trial, pembrolizumab-PD-1 blocking was linked to a high overall response rate, a good safety profile, and some signs of tumor reduction after treatment.