Prospective, open label study to assess the pharmacokinetics, safety \& efficacy of anidulafungin when used to treat children (aged 1 month - \< 18 years) with invasive candidiasis, including candidemia (ICC). To participate in the study, at the time of enrollment subjects must (1) have either a confirmed diagnosis of ICC or mycological evidence highly suggestive of Candida sp or (2) in infants 1 month to \< 2 years only, be at high risk of candidiasis. All subjects meeting screening criteria receive IV anidulafungin. Subjects will be stratified by age (1 month - \< 2 years; 2 years - \< 5 years; 5 years - \< 18 years). Subjects may be switched to oral fluconazole, provided that the pre-specified criteria are met. Subjects with microbiologically confirmed ICC must have a minimum total treatment duration of 14 days. The maximum allowed treatment duration of anidulafungin is 35 days; the maximum total treatment duration for the study is 49 days. At selected centers, anidulafungin pharmacokinetics will be assessed in the first 6 subjects age 1 month - \< 2 years to confirm the recommended dosage regimen. A population PK-PD analysis will be performed in all other enrolled subjects. Subjects will be followed for safety through 6 week FU visit. Efficacy for subjects with confirmed ICC will be assessed at EOIVT, EOT, 2-week FU and 6-week FU visits.
