A Study of the Safety and Efficacy of Posaconazole Versus Voriconazole for the Treatment of Invasive Aspergillosis (MK-5592-069)

Inclusion Criteria:

- Weight >40 kg (88 lb) and ≤150 kg (330 lb); if between 13 and 14 years of age must
weigh >= 50 kg (110 lb)

- Must meet the criteria for proven, probable, or possible IA. If with possible IA at
time of randomization must be willing or be in process of an ongoing diagnostic work
up which is anticipated to result in a mycological diagnosis of proven or probable IA
post-randomization

- Must have a central line (e.g., central venous catheter, peripherally-inserted central
catheter, etc.) in place or planned to be in place prior to beginning IV study
therapy. If without central catheter access, must be clinically stable and able to
receive oral study therapy

- Acute IA defined as duration of clinical syndrome of <30 days.

- Female participants of child-bearing potential must be using a medically accepted
method of birth control before beginning study-drug treatment and agree to continue
its use for 30 days after stopping study medication

- Is not taking prohibited antifungal prophylaxis or treatment

Exclusion Criteria:

- Chronic (>1 month duration) IA, relapsed/recurrent IA, or refractory IA which has not
responded to antifungal therapy.

- Chronic pulmonary aspergillosis, pulmonary sarcoidosis, aspergilloma, or allergic
bronchopulmonary aspergillosis (ABPA).

- Known mixed invasive mold fungal infection including Zygomycetes, and/or a known
invasive Aspergillus fungal infection in which either study drug may not be considered
active.

- Receipt of any systemic (oral, intravenous, or inhaled) antifungal therapy for this
infection episode for 4 or more consecutive days (>= 96 hours) immediately before
randomization.

- Developed the current episode of IA infection during receipt of >13 days of antifungal
prophylaxis with an agent considered to be a mold-active antifungal agent.

- Receipt of posaconazole or voriconazole as empirical treatment for this infection for
4 days (96 hours) or more within the 15 days immediately before randomization.

- Known hypersensitivity or other serious adverse reaction to any azole antifungal
therapy or to any other ingredient of the study medication used.

- Females who are pregnant, intend to become pregnant, or are nursing at the time of
randomization.

- Known history of Torsade de Pointes, unstable cardiac arrhythmia or proarrhythmic
conditions, or a history of recent myocardial infarction within 90 days of study
entry.

- Has significant liver dysfunction

- Hepatic cirrhosis or a Child-Pugh score of C (severe hepatic impairment) at the time
of randomization.

- Severe renal insufficiency (estimated creatinine clearance <20 mL/min) or on

hemodialysis at the time of randomization or likely to require dialysis during the study.

- Known hereditary problem of galactose intolerance, Lapp lactase deficiency, or
glucose-galactose malabsorption.

- Acute symptomatic pancreatitis within 6 months of study entry or a diagnosis of
chronic pancreatitis at the time of randomization.

- Active skin lesion consistent with squamous cell carcinoma at the time of
randomization, or a current or prior history of malignant melanoma within 5 years of
study entry.

- On artificial ventilation or receiving acute Continuous Positive Airway Pressure
(CPAP)/Bilevel Positive Airway Pressure (BPAP) at the time of randomization.

- Known or suspected Gilbert's disease at the time of randomization.

- Requires treatment with other medications that cannot be stopped and for which there
is a known contraindication to co-administration of one or more of the study drugs.