Open, Pharmacokinetic Study of Caspofungin Acetate in Immunocompromised Young Children With Febrile Neutropenia (0991-042)

Inclusion Criteria: * Patient is 3 to 24 months of age with one or more of the following conditions: * Leukemia, lymphoma, or other cancers * Bone marrow or peripheral stem transplantation * High dose chemotherapy leading to a decrease in white blood cells * Aplastic anemia * Patient has an absolute neutrophil count \<500 mm3 (a specific type of white blood cell that fights infection) AND at least one recording of fever \> 38 degreesC (oral or oral equivalent) within 72 hours of screening. Exclusion Criteria: * Patient is \<3 months or \>24 months of age at the time of study drug administration * Patient has proven or probable invasive fungal infection at the time of enrollment * Patient has certain blood clotting or liver function abnormalities * Patient is hemodynamically unstable, exhibits hemodynamic compromise or is not expected to survive at least 5 days * Patient is taking rifampin, cyclosporin A, phenytoin, carbamazepine, or phenobarbital.