13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
In carcinogenicity studies in rats and mice, oxaprozin administration for 2 years was associated with the exacerbation of liver neoplasms (hepatic adenomas and carcinomas) in male CD mice, but not in female CD mice or male or female rats treated with up to 216 mg/kg via the diet (1.2-times the maximum daily human dose of 1800 mg based on body surface area). The significance of this species-specific finding to man is unknown.
Oxaprozin was not genotoxic in the Ames test, forward mutation in yeast and Chinese hamster ovary (CHO) cells, DNA repair testing in CHO cells, micronucleus testing in mouse bone marrow, chromosomal aberration testing in human lymphocytes, or cell transformation testing in mouse fibroblast.
Impairment of Fertility
Oxaprozin administration was not associated with impairment of fertility in male and female rats at oral doses up to 200 mg/kg/day (1.1-times the maximum recommended human daily dose [MRHD] of 1800 mg based on a body surface area comparison). However, testicular degeneration was observed in beagle dogs treated with 37.5 mg/kg/day (0.7-times the MRHD based on body surface area) of oxaprozin for 42 days or 6 months, a finding not confirmed in other species. The clinical relevance of this finding is not known.