Wang Xin, Tian Chao, Zhao Rui, Sun Li, Pan Dongsheng, Qu Zhe, Miao Yufa, Li Lulu, Wang Tiantian, Li Jinfeng, Geng Xingchao
Objective: To conduct the in vivo toxicity study of repeated administration of oncolytic virus drug HSV-1/hPD-1 in cynomolgus macaques, and to find out the safety dose range, so as to provide informative references for subsequent clinical trials. Methods: Thirty cynomolgus macaques were randomly divided into three groups including control group, HSV-1/hPD-1 low and high-dose groups (1.0×108 , 4.0×108 pfu), with five animals per sex per group. The monkeys were intramuscularly injected twice a week for consecutive six weeks following an eight-week recovery phase. Animals were observed clinical symptoms daily and irritation of injective sites on days 1 and 2 post injection. Body weight was measured once weekly and food consumption was visually estimated daily. Other toxicological parameters including safety pharmacology (body temperature, blood pressure, electrocardiogram), clinical pathology (hematology, coagulation, biochemical, urinalysis), immunology (T lymphocyte, cytokine, immunogenicity), histopathology and organ weight were scheduled to be detected at the quarantine period, after the fi rst dosing, the end of dosing and recovery period. Results: All animas tolerated well and didn’t show obvious changes in clinical signs, injective irritation, body weight, food consumption, and pharmacology and clinical pathology indexes. On day 41, increased CD3+ CD4+ T lymphocytes were inspected in low dose animals. From days 13 to 97, antibody against HSV-1 vector, expressed PD-1 protein and antiantibody were continuously detected in low and high dose animals, which were considered correlation with immunostimulation and immunogenicity attributed to test articles. The histopathological fi ndings were recoverable minimal to moderate mixed cell infiltration in injection site of low and high dose animals and unrecoverable minimal myelin/axonal damage in sciatic nerve of high dose animals. The change of organ weight wasn’t detected in both groups. Conclusion: After repeated administration of oncolytic virus drug HSV-1/hPD-1, cynomolgus macaques showed good tolerance in vivo, and the no-observed-adverse-eff ect-level (NOAEL) of the test substance was 1.0×108 pfu. Our research data could be used to support subsequent clinical trials.