“The toxicology program was carried out in cynomolgus monkeys, as it was demonstrated that the cynomolgus monkey and human have relevant HER2 sequence homology and affinity.”
Similar HER2 ECD affinity human 0.74 nM vs monkey 0.47 nM; weaker for dog, no binding in rodents
“It was demonstrated that zanidatamab binds with similar affinity to human and cynomolgus monkey HER2 ECD (Kd = 0.74 and 0.47 nM, respectively), while the affinity for dog was lower (Kd = 4.07 nM) and no affinity was demonstrated for rodents”
No surrogate; clinical molecule tested in cynomolgus monkey
“The cynomolgus monkey is considered a suitable species for characterizing the PK of zanidatamab as it binds both human and monkey HER2 molecules with similar subnanomolar affinity.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗