Millennium Pharmaceuticals Inc. is using an in vivo screening platform from Presage Biosciences Inc. to speed up its preclinical characterization of cancer combination therapies. The platform enables simultaneous comparison of up to four treatments within a single tumor in a live mouse and could better predict efficacy than the in vitro assays that usually precede large-scale animal studies.

Typically, the first in vivo assessment of a preclinical cancer compound can occur only after optimization cycles of in vitro enzyme assays and cancer cell culture studies, because a limited amount of compound is available, according to Millennium CSO Joseph Bolen. However, it is not unusual for the activity of compounds tested in monolayer cell culture to fail to reproduce in the same cells grown as subcutaneous xenografts in rodents.