An In Vivo Study of Local Administration of Low-dose Anti-PD-1 Antibody Using an Oral Cancer Cell Line.

BACKGROUND/AIM: The immunotherapy approach using anti-programmed cell death 1 (PD-1) antibody has been demonstrated in oral cancer treatment. However, serious immune-related adverse events (irAE) have been reported. If local administration of small doses of anti-PD-1 antibody via intraarterial chemoradiotherapy could have the same antitumor effect of systemic administration, this can reduce irAE and medical expenses. In this study, we investigate the antitumor effects of local and systemic administration of a small amount of anti-PD-1 antibody, the overall survival (OS), and the immune environment around cancer. MATERIALS AND METHODS: A mouse buccal mucosal oral squamous cell carcinoma cell line (Sq-1979) was used, and anti-mouse PD-1 was used as the drug. The cell line was transplanted to mouse, and the drug was locally (30 mg/body) and systemically (300 mg/body) administered in a dose. The tumor shrinkage rate and antitumor effect were examined 21 and 29 days after the start of administration. The OS was also compared in each of the groups. Furthermore, the subcutaneous growth of the tumors was inhibited, and the expressions of PD-L1, CD8T cells, perforin, and granzyme B were examined. RESULTS: We found that the local low-dose and systemic groups had the same antitumor effect, OS also showed a significant prolongation. In addition, indicated that the expression of granzyme B was higher in the local low-dose group. CONCLUSION: Local low-dose administration of anti-PD-1 antibody showed the same antitumor effect and OS as systemic normal-dose administration. Therefore, local low-dose administration in oral cancer can be useful.