MK-7625A Plus Metronidazole Versus Meropenem in Pediatric Participants With Complicated Intra-Abdominal Infection (cIAI) (MK-7625A-035)

Inclusion Criteria:

- Has a legal representative who provides written informed consent on the participant's
behalf and provides age-appropriate written informed assent (as applicable) for the
trial.

- Aged from birth (defined as >32 weeks gestational age and ≥7 days postnatal) to <18
years of age.

- Require IV antibacterial therapy for the treatment of presumed or documented cIAI.

- Has an operative procedure for the current diagnosis and management of cIAI planned or
completed within 24 hours of the first dose of an antibacterial drug.

- Has in compliance baseline intra-abdominal specimen collection.

- Is not of reproductive potential; but if of reproductive potential agrees to avoid
becoming pregnant or impregnating a partner during screening, while receiving study
treatment and for at least 30 days after the last dose of study treatment.

- Female of reproductive potential is not pregnant, and not planning to become pregnant
within 30 days of the last day of treatment administration; and is nonlactating.

Exclusion Criteria:

- Is currently participating in or has participated in an interventional clinical trial
with an investigational compound or device within 30 days prior to the first dose of
study treatment in this current trial.

- Has previously participated in any trial of ceftolozane or ceftolozane/tazobactam or
has enrolled previously in the current trial and been discontinued.

- Has a history of any moderate or severe hypersensitivity (eg, anaphylaxis), allergic
reaction, or other contraindication to any of the following: β-lactam antibiotics (eg,
penicillins, cephalosporins, and carbapenems), β-lactamase inhibitors (eg, tazobactam,
sulbactam, clavulanic acid, avibactam), or metronidazole.

- Has an IAI within the past 1 year prior to randomization known to be caused by a
pathogen resistant to either IV study treatment.

- Has a concomitant infection at the time of randomization that requires nonstudy
systemic antibacterial therapy in addition to IV study treatment or oral step-down
therapy.

- Has received potentially therapeutic antibacterial therapy for a duration more than 24
hours during the 48 hours preceding the first dose of study treatment, unless is
considered to be failing antibiotic therapy for cIAI.

- Has any of the following: a) intractable cIAI that the investigator anticipates would
require more than 14 days of study treatment; b) abdominal wall abscess; c) small
bowel obstruction; d) ischemic bowel disease without perforation; e) traumatic bowel
perforation with surgery within 12 hours of perforation; f) perforation of
gastroduodenal ulcers requiring surgery within 24 hours of perforation; g) suspected
uncomplicated intra-abdominal infection (eg, cholecystitis without rupture or
extension beyond the gallbladder wall); h) acute suppurative cholangitis; i) infected
necrotizing pancreatitis; j) pancreatic abscess.

- Has severe impairment of renal function.

- Has a seizure disorder or is anticipated to be treated with divalproex sodium or
valproic acid during the course of study treatment.

- Is receiving, or is expected to receive, any prohibited medications.

- Has any rapidly progressing disease or immediately life-threatening illness, including
acute hepatic failure, respiratory failure, or septic shock.

- Has an immunocompromising condition.

- Has a history of malignancy ≤5 years prior to signing informed consent.

- Is planning to receive suppressive/prophylactic antibiotics with gram-negative
activity after completion of study treatment.