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Fertility and Early Embryonic Development Toxicity of hzVSF-v13 in Sprague-Dawley Rats
Ji-Seong Jeong1,2, Sang-Yun Kim1, Jinsoo Lee3
1Laboratory of Developmental and Reproductive Toxicology Research, Korea Institute of Toxicology, Daejeon, Republic of Korea.
Abstract:
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.
Insights
Humanized virus suppressing factor-variant 13 (hzVSF-v13) showed no adverse effects on general toxicity, fertility, or early embryonic development in rats. The no-observed-adverse-effect level (NOAEL) was determined to be 100 mg/kg.
Area of Science:
- Immunology
- Toxicology
- Reproductive Biology
Background:
- Humanized virus suppressing factor-variant 13 (hzVSF-v13) is a potential therapeutic monoclonal antibody for COVID-19.
- Comprehensive safety evaluation requires assessing fertility and embryonic developmental toxicity.
- The toxicological profile of hzVSF-v13, particularly regarding reproductive health, was previously unexplored.
Purpose of the Study:
- To evaluate the general toxicity of hzVSF-v13.
- To assess the effects of hzVSF-v13 on fertility and early embryonic development.
- To determine the no-observed-adverse-effect level (NOAEL) for hzVSF-v13 in Sprague-Dawley rats.
Main Methods:
- Sprague-Dawley rats were administered hzVSF-v13 intravenously once weekly at doses of 0, 25, 50, and 100 mg/kg.
- Male rats received treatment for 4 weeks prior to mating and until sacrifice; females received treatment for 2 weeks prior to mating through implantation.
- General toxicological parameters, mating performance, fertility, sperm analysis, and litter parameters were assessed.
Main Results:
- No treatment-related adverse effects were observed in general toxicological parameters (body weight, food consumption, macroscopic findings, organ weights) in either sex.
- hzVSF-v13 did not impact mating performance, fertility, sperm parameters, or litter characteristics at any tested dose.
- The no-observed-adverse-effect level (NOAEL) for general toxicity, fertility, and early embryonic development was established at 100 mg/kg.
Conclusions:
- hzVSF-v13 demonstrates a favorable safety profile concerning general toxicity, fertility, and early embryonic development in Sprague-Dawley rats.
- The highest tested dose of 100 mg/kg was identified as the NOAEL, indicating no observed adverse effects.
- These findings support the continued development of hzVSF-v13 as a potential therapeutic for COVID-19, with no identified reproductive contraindications at the tested levels.

