Species and sex differences in the blood clearance and immunogenicity of PEGylated uricase: A comparative 26-week toxicity study in rats and monkeys

In this study, the toxicity of mPEG-UHC was studied in rats and monkeys over a 26-week period of repeated intravenous dosing. There were no obvious toxic reactions in the tested animals, with the exception of mPEG-UHC blood clearance and immunogenicity. After repeated injections of mPEG-UHC, rapid loss of uricolytic activity (RLA) was not detected in rats, whereas RLA was observed in 44.4% of drug-treated monkeys. In these monkeys, RLA was observed in 11.1% of males and 77.8% of females, and such incidences increased with higher dosing. High titres of anti-uricase IgG antibodies were associated with RLA but did not result in any toxicity. Remission and recurrence of RLA occurred in one female monkey in the high-dose group because of suppressed and altered immune responses in this animal. The predicted incidence of RLA after repeated injections of mPEG-UHC in gout patients may be lower than that of pegloticase. In this study, the no-observed-adverse-effect levels (NOAELs) of mPEG-UHC in rats and monkeys were 32.0 mg/kg and 20.0 mg/kg, respectively. Therefore, the results showed that rats and monkeys could tolerate long-term and high-dose administrations of mPEG-UHC, and mPEG-UHC blood clearance and immunogenicity showed obvious species and sex differences. These findings will provide valuable information to direct the clinical use of mPEG-UHC.
Source: Life Sciences - Category: Biology Source Type: research