Subjects with intra-abdominal infection requiring surgery and Intensive Care Unit stay will be treated early with micafungin or placebo to determine the incidence and time to confirmation of fungal infection.

Subjects will be assessed at the following visits:

• Baseline (after surgery, prior to randomization)
• End of Treatment (EOT) visit (EOT is defined as: requires alternative antifungal, sufficient improvement of surgical condition, confirmed fungal infection or death)
• End of Study visit (28 days after the EOT visit)
• Long-term Follow up visit (90 days after the EOT visit)

Inclusion Criteria:

• Intra-abdominal infection requiring surgery and Intensive Care Unit stay
• If Community Acquired Intra-Abdominal Infection, at least 72 hours (but not more than 120 hours) of Intensive Care Unit stay, counted from the end of surgery, and a further expected duration of Intensive Care Unit stay of ≥ 48 hours
• If Nosocomial Intra-Abdominal Infection, duration of Intensive Care Unit stay ≤ 48 hours, counted from the end of surgery, and a further expected duration of Intensive Care Unit stay of ≥ 48 hours
• Female subject of childbearing potential must have a negative urine or serum pregnancy test prior to randomization and must agree to maintain highly effective birth control during the study

Exclusion Criteria:

• Acute pancreatitis
• Neutropenia (ANC <1,000/mm3) at the time of randomization
• Infected intra-peritoneal dialysis
• Patients undergoing solid organ transplantation
• Documented invasive candidiasis at the time of randomization
• Expected survival < 48 hours
• Any systemically active anti-fungal within 14 days prior to administration of the study drug
• Allergy, hypersensitivity, or any serious reaction to an echinocandin anti-fungal or any of the study drug excipients
• Currently receiving and/or has taken an investigational drug within 28 days prior to randomization
• Pregnant woman or breast-feeding mother
• 'Do Not Resuscitate' order

Access to anonymized individual participant level data collected during the study, in addition to study-related supporting documentation, is planned for studies conducted with approved product indications and formulations, as well as products terminated during development. Studies conducted with product indications or formulations that remain active in development are assessed after study completion to determine if Individual Participant Data can be shared. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.

Access to participant level data is offered to researchers after publication of the primary manuscript (if applicable) and is available as long as Astellas has legal authority to provide the data.

Researchers must submit a proposal to conduct a scientifically relevant analysis of the study data. The research proposal is reviewed by an Independent Research Panel. If the proposal is approved, access to the study data is provided in a secure data sharing environment after receipt of a signed Data Sharing Agreement.