In addition to an understanding of a new compounds toxicity and maximum tolerated dose in a multiple dose protocol, it is also important to gain some insight into the pharmacology of a new compound prior to committing to a study designed to evaluate efficacy.

Design a better study.

At a minimum, an understanding of plasma compound levels following the introduction of a compound gives an idea of how long the compound remains available, and provides a valuable comparison of competing compounds. Target tissue levels are also very valuable, particularly in the context of tumor studies, to provide a level of confidence that the new compound reaches/remains in the tumor. Additionally, target organ levels for suspected compound toxicities (if known) may be useful before moving ahead with an efficacy study.