Cynomolgus monkey (clinical antibody); mouse with surrogate antibody for fertility/EFD
“The nonclinical program with mepolizumab was conducted in Cynomolgus monkeys, which were determined to be the only pharmacologically relevant nonclinical test species.”
✓ VerifiedFDA pharmacology/toxicology review, p. 9Source ↗
Why that species
Binds human and nonhuman primate IL-5 only; no binding to mouse or rat IL-5
“The species specificity of mepolizumab was restricted to human and nonhuman primate IL-5 only. Mepolizumab did not bind to mouse or rat IL-5.”
✓ VerifiedFDA pharmacology/toxicology review, p. 125Source ↗
Surrogate molecule
Yes: SB264091, rat anti-human IL-5 IgG2b cross-reacting with murine IL-5, used for mouse fertility and embryofetal development study
“Fertility and embryofetal development were evaluated with male and female CD-1 mice treated with SB264091, a rat anti-human IL-5 surrogate monoclonal antibody (lgG2b), which cross reacts with human and murine IL-5.”
✓ VerifiedFDA pharmacology/toxicology review, p. 129Source ↗