Safety, Tolerability, Efficacy and Pharmacokinetics of Imipenem/Cilastatin/Relebactam (MK-7655A) in Pediatric Participants With Gram-negative Bacterial Infection (MK-7655A-021)

Inclusion Criteria

Inclusion Criteria include but are not limited to:

• Requires hospitalization and treatment with intravenous (IV) antibacterial therapy for confirmed or suspected gram-negative bacterial infection (in the absence of meningitis), and is expected to require hospitalization through completion of IV study intervention, with at least 1 of the following primary infection types: Hospital-acquired bacterial pneumonia (HABP) or ventilator-associated bacterial pneumonia (VABP); complicated intra-abdominal infection (cIAI); or complicated urinary tract infection (cUTI).
• For Age Cohorts 4 and 5, participant is at least 37 weeks postmenstrual age at the time of signing the informed consent/assent.
• If female, must not be pregnant or breastfeeding, and at least 1 of the following conditions must apply: must not be a woman of childbearing potential (WOCBP); OR, if a WOCBP, must agree to follow contraceptive guidance during the intervention period and for at least 24 hours after the last dose of study intervention.
• Has sufficient intravascular access to receive study drug through an existing peripheral or central line.

Exclusion Criteria

Exclusion Criteria include but are not limited to:

• Is expected to survive less than 72 hours.
• Has a concurrent infection that would interfere with evaluation of response to the study antibacterials (imipenem/cilastatin/relebactam (IMI/REL) or Active Control), including any of the following: endocarditis; osteomyelitis; meningitis; prosthetic joint infection; active pulmonary tuberculosis; disseminated fungal infection; concomitant infection at the time of randomization that requires non-study systemic antibacterial therapy in addition to IV study treatment or oral step-down therapy (medications with only gram-positive activity [e.g., vancomycin, linezolid] are allowed).
• Has HABP/VABP caused by an obstructive process, including lung cancer (or other malignancy metastatic to the lungs resulting in pulmonary obstruction) or other known obstruction.
• Has a cUTI, with any of the following: complete obstruction of any portion of the urinary tract (i.e., requiring a permanent indwelling urinary catheter or instrumentation); documented reflux of ileal loop urinary diversion; suspected or confirmed perinephric or intrarenal abscess; suspected or confirmed prostatitis, urethritis, or epididymitis; trauma to pelvis/urinary tract; presence of indwelling urinary catheter which cannot be removed at study entry.
• Has any of the following medical conditions at screening: history of a seizure disorder (requiring ongoing treatment with anti-convulsive therapy or prior treatment with anti-convulsive therapy within the last 3 years); cystic fibrosis; history of serious allergy, hypersensitivity (e.g., anaphylaxis), or any serious reaction to IMI, or to any carbapenem, cephalosporin, penicillin, or other β-lactam agent, or to other β-lactamase inhibitors (e.g., tazobactam, sulbactam, clavulanic acid, avibactam).
• Has a history or current evidence of any condition, therapy, laboratory abnormality, or other circumstance that might expose the participant to risk by participating in the study, confound study results, or interfere with the participant's participation for the full duration of the study.
• If less than 3 months of age, has received more than 72 hours of empiric antibacterial treatment for suspected meningitis prior to initiation of IV study intervention.
• For all Age Cohorts, provided all other eligibility criteria are met, the following participants may be enrolled:
• A participant failing prior antibiotic therapy for a current episode of cUTI or HABP/VABP who: Has received the prior antibacterial treatment for at least 48 hours; Has persistent clinical or radiographic findings clearly indicating ongoing infection; Fulfills other laboratory or microbiology criteria for enrollment
• A participant failing prior antibiotic therapy for a current episode of cIAI who: Has received th