Efficacy and safety of molecularly targeted agents and immune checkpoint inhibitors for unresectable or recurrent/metastatic oral cancer in Japan

Background/purpose: For unresectable recurrent/metastatic head and neck cancer, pembrolizumab alone or pembrolizumab combined with cisplatin and 5-fluorouracil is the first-line therapy, depending on the PD-L1 combined positive score (CPS). However, this is based on clinical studies of head and neck cancer, and few similar studies have been conducted on oral cancer alone. This study aimed to investigate the current status of pharmacotherapy for unresectable, recurrent, or metastatic oral cancer. Materials and methods: Patients with unresectable or recurrent/metastatic oral cancer who received cetuximab, nivolumab, or pembrolizumab as first-line treatment were reviewed. Overall survival (OS), progression-free survival (PFS), PFS 2 (PFS2), overall response rate (ORR), disease control rate (DCR), and immune-related adverse events were obtained from medical records. Results: A total of 155 patients were enrolled from six hospitals. The ORR in the nivolumab, pembrolizumab, and cetuximab groups was 17.2 %, 4.2 %, and 21.6 %, respectively, and the DCR was 37.9 %, 41.7 %, and 58.8 %, respectively. Median OS in nivolumab, pembrolizumab, and cetuximab groups was 10.3, 9.5, and 11.1 months, respectively. No significant differences were observed in survival among the three groups. The small number of cases and the retrospective nature of the study precluded the determination of the more effective first-line treatment among the three drugs. Conclusion: The current statuses of nivolumab, pembrolizumab, and cetuximab in unresectable recurrent metastatic oral cancer was reported.