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 therapyfor confirmed or suspected gram-negative bacterial infection (in the absence ofmeningitis), and is expected to require hospitalization through completion of IVstudy intervention, with at least 1 of the following primary infection types:Hospital-acquired bacterial pneumonia (HABP) or ventilator-associated bacterialpneumonia (VABP); complicated intra-abdominal infection (cIAI); or complicatedurinary tract infection (cUTI).

• For Age Cohorts 4 and 5, participant is at least 37 weeks postmenstrual age at thetime of signing the informed consent/assent.

• If female, must not be pregnant or breastfeeding, and at least 1 of the followingconditions must apply: must not be a woman of childbearing potential (WOCBP); OR, ifa WOCBP, must agree to follow contraceptive guidance during the intervention periodand for at least 24 hours after the last dose of study intervention.

• Has sufficient intravascular access to receive study drug through an existingperipheral 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 thestudy antibacterials (imipenem/cilastatin/relebactam (IMI/REL) or Active Control),including any of the following: endocarditis; osteomyelitis; meningitis; prostheticjoint infection; active pulmonary tuberculosis; disseminated fungal infection;concomitant infection at the time of randomization that requires non-study systemicantibacterial therapy in addition to IV study treatment or oral step-down therapy (medications with only gram-positive activity [e.g., vancomycin, linezolid] areallowed).

• Has HABP/VABP caused by an obstructive process, including lung cancer (or othermalignancy metastatic to the lungs resulting in pulmonary obstruction) or otherknown obstruction.

• Has a cUTI, with any of the following: complete obstruction of any portion of theurinary tract (i.e., requiring a permanent indwelling urinary catheter orinstrumentation); documented reflux of ileal loop urinary diversion; suspected orconfirmed perinephric or intrarenal abscess; suspected or confirmed prostatitis,urethritis, or epididymitis; trauma to pelvis/urinary tract; presence of indwellingurinary catheter which cannot be removed at study entry.

• Has any of the following medical conditions at screening: history of a seizuredisorder (requiring ongoing treatment with anti-convulsive therapy or priortreatment with anti-convulsive therapy within the last 3 years); cystic fibrosis;history of serious allergy, hypersensitivity (e.g., anaphylaxis), or any seriousreaction to IMI, or to any carbapenem, cephalosporin, penicillin, or other β-lactamagent, or to other β-lactamase inhibitors (e.g., tazobactam, sulbactam, clavulanicacid, 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 inthe study, confound study results, or interfere with the participant's participationfor the full duration of the study.

• If less than 3 months of age, has received more than 72 hours of empiricantibacterial treatment for suspected meningitis prior to initiation of IV studyintervention.

• For all Age Cohorts, provided all other eligibility criteria are met, the followingparticipants may be enrolled:

• A participant failing prior antibiotic therapy for a current episode of cUTI orHABP/VABP who: Has received the prior antibacterial treatment for at least 48hours; Has persistent clinical or radiographic findings clearly indicatingongoing infection; Fulfills other laboratory or microbiology criteria forenrollment

• A participant failing prior antibiotic therapy for a current episode of cIAIwho: Has received the prior antibacterial treatment for at least 48 hours; Haspersistent clinical or radiographic findings clearly indicating ongoinginfection; Fulfills other laboratory or microbiology criteria for enrollment;Has planned operative intervention no more than 24 hours after first dose ofstudy treatment; Has not received any further nonstudy antibioticspostoperatively

• If 3 months of age or older, or <3 months of age without suspected meningitis, hasreceived potentially therapeutic antibacterial therapy (e.g., with gram-negativeactivity), including bladder infusions with topical urinary antiseptics orantibacterial agents, for a duration of more than 24 hours during the 48 hourspreceding the first dose of study intervention.

• Is anticipated to be treated with any of the following medications: valproic acid ordivalproex sodium (or has used valproic acid or divalproex sodium in the 2 weeksprior to screening) through 24 hours after completion of the final dose of IV studyintervention for participants who receive IMI/REL or carbapenem; concomitant IV,oral, or inhaled antimicrobial agents with gram-negative activity, in addition tothose designated in the study intervention groups, during the course of all (IV/oral) study intervention; planned receipt of suppressive/prophylacticantibiotics with gram-negative activity after completion of study intervention.

• Is currently participating in or has participated in an interventional clinicalstudy with an investigational compound or device within 30 days prior to screening.

• Has enrolled previously in the current study and been discontinued or has receivedREL for any other reason.

• Has an estimated creatinine clearance (based on the Cockcroft-Gault equation, forparticipants ≥12 years of age or estimated glomerular filtration rate (eGFR), basedon the modified Schwartz equation, for participants <12 years of age below thatspecified for the appropriate age range; or requires peritoneal dialysis,hemodialysis, or hemofiltration.

• Has alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥5 × upperlimit of normal (ULN) at the time of screening. NOTE: Patients with acute hepaticfailure or acute decompensation of chronic hepatic failure should also be excluded.

• Is a user of recreational or illicit drugs or has had a recent history of drug oralcohol abuse or dependence.

• Is or has an immediate family member (e.g., spouse, parent/legal guardian, sibling,or child) who is investigational site or Sponsor staff directly involved with thisstudy.