Fertility and Early Embryonic Development Toxicity of hzVSF-v13 in Sprague-Dawley Rats.

Humanized virus suppressing factor-variant 13 (hzVSF-v13), a monoclonal IgG4 antibody, is a potential therapeutic candidate for COVID-19. Although fertility and embryonic developmental toxicity studies are crucial for the safety evaluation of new drugs, the toxicological profile of hzVSF-v13 remains unexplored. This study was performed to assess its effects on general toxicity, fertility, and early embryonic development in Sprague-Dawley rats administered intravenously once weekly at doses of 0, 25, 50, and 100 mg/kg. Males received the test article starting 4 weeks before mating and continuing until the day prior to sacrifice, while females were treated beginning 2 weeks prior to mating and continuing through the implantation. No treatment-related effects were observed on general toxicological parameters, including body weight, food consumption, macroscopic findings, or organ weights in both sexes. Additionally, hzVSF-v13 did not affect the mating performance, fertility, sperm analysis, or litter parameters in cesarean section at doses up to 100 mg/kg. Under the experimental conditions, the no-observed-adverse-effect level (NOAEL) of hzVSF-v13 for general toxicity, fertility, and early embryonic development was considered to be 100 mg/kg.