2004 Volume 45 Issue 2 Pages 83-91
Preclinical evaluation of the efficacy of an antifungal agent is basically conducted by measuring both the in vitro and the in vivo antifungal activity of the drug using appropriate infection models.
Although the first requisite for a method measuring in vitro activity is to obtain results with good reproducibility, an additional requirement is that there be good correlation with the in vivo activity, as described later. For the first condition, in recent years the National Committee for Clinical Laboratory Standards in the United States and the Standardization Committee of the Japanese Society for Medical Mycology have proposed reference techniques with the objective of standardizing drug susceptibility testing; these have been used extensively in measuring antifungal activities of novel agents. However, there are several issues involved when these methods are applied to newly developed drugs. First, standard methods are for particular currently available antifungal agents, but MIC determining standards have not been established for other agents. Reproducibility is therefore not guaranteed. Second, there is a question of whether reliable results can be obtained to test an antifungal spectrum with a limited number of fungal species. On the other hand, in vivo evaluation of novel antifungal agents is extremely important to predict the clinical outcome at the preclinical stage. The important requirements for this in vivo experimental system are: use of an animal model of mycosis that resembles the pathophysiology in humans; use of an administration schedule corresponding to that used in clinical studies, and evaluation of the therapeutic effect considering the dose and administration period.
This review presents the present status of preclinical evaluation test methods and discusses the issues.
