huCD52 mouse developmental NOAEL: below clinical exposure by Cmax; 0.6- to 4.4-fold by AUC
“Based on Cmax values, the exposures were significantly below those observed in the clinical setting, following administration of the recommended therapeutic dose. Higher exposure margins were established by the applicant based on AUC values obtained in a PK study. The use of these AUC data yielded exposure margins of 0.6- to 4.4-fold.”
No NOAEL defined; dose-limiting infections or hypersensitivity causing deaths; reduced CD52 affinity in monkey limits model
“dose-limiting toxicity (increased susceptibility to infections or hypersensitivity leading to lethality/early sacrifice) and limitation of the animal model (decreased affinity of alemtuzumab for CD52 in the cynomolgus monkey).”