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Published on: March 6, 2018
Developmental toxicity study of CBLB502 in Wistar rats
1Cleveland BioLabs, Inc., Buffalo, NY 14203, United States.
Abstract:
CBLB502 is a derivative of a microbial protein that binds to Toll-like receptor 5. It is demonstrated to reduce inflammatory response from acute stresses, such as radiation in animal models. We determined the potential developmental toxicity of CBLB502 in rats. Four groups of 25 time-mated female Wistar rats/group received subcutaneously 0, 30, 100, or 300 μg/kg/day of CBLB502 from Gestation Days (GD) 6 to 17 at a dose volume of 1.0 mL/kg. Toxicokinetic evaluation was performed on GD 6 and 17. On GD 20 C-section was performed for uterine evaluation and blood samples collected from each dam for immunogenicity assay. Significant decrease in gestation body weight, weight changes and food consumption indicative of maternal toxicity were observed in all dose groups. Also adjusted body weight and weight changes were seen at 300 μg/kg/day. No external, visceral and skeletal abnormalities were observed. The NOAEL for developmental toxicity was estimated to be ≥300 μg/kg/day.
Insights
CBLB502, a Toll-like receptor 5 agonist, showed no developmental toxicity in rats. Maternal toxicity was observed at all doses, but no fetal abnormalities were detected.
Area of Science:
- Toxicology
- Immunology
- Developmental Biology
Background:
- CBLB502 is a microbial protein derivative that targets Toll-like receptor 5.
- It has demonstrated anti-inflammatory effects against acute stresses like radiation in preclinical models.
Purpose of the Study:
- To evaluate the potential developmental toxicity of CBLB502 in a rat model.
- To establish the No Observed Adverse Effect Level (NOAEL) for developmental toxicity.
Main Methods:
- Time-mated female Wistar rats received CBLB502 (0, 30, 100, or 300 μg/kg/day) subcutaneously from Gestation Day 6 to 17.
- Toxicokinetic, immunogenicity, and uterine evaluations were performed.
- Maternal body weight, weight changes, and food consumption were monitored.
Main Results:
- Maternal toxicity, including decreased body weight and food consumption, was observed across all dose groups.
- Adjusted body weight and weight changes indicated toxicity at the highest dose (300 μg/kg/day).
- No external, visceral, or skeletal abnormalities were found in the fetuses.
Conclusions:
- The No Observed Adverse Effect Level (NOAEL) for developmental toxicity was determined to be ≥300 μg/kg/day.
- CBLB502 did not induce developmental toxicity in rats, despite causing maternal toxicity at tested doses.
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