Pharmacokinetic and Safety Study of Ceftolozane/Tazobactam in Pediatric Participants Receiving Antibiotic Therapy for Proven or Suspected Gram-negative Infection or for Peri-operative Prophylaxis (MK-7625A-010)

Screening assessments will occur within 48 hours of study drug administration (Day 1).
Baseline assessments will be performed following eligibility verification based on screening
assessments.

Participants will be monitored for safety 24 hours post study drug infusion. The site will
contact the participant and/or parent (or appropriate legal representative) via telephone at
Study Day 8 (± 2 days) for assessment of adverse events and concomitant medications and
procedures.

In each age cohort, an interim analysis of PK and safety data will be conducted after 3
participants have received the initially proposed dose. The interim analysis will determine
whether this initial dose was appropriate based on pre-defined criteria.

If data from the interim analysis demonstrates that the initially proposed dose meets the
criteria above, enrollment will continue with the same dose administered to 3 additional
participants. However, if the interim analysis demonstrates that a new optimized adjusted
dose is required, the new adjusted dose will be administered to 3 new participants of the
same age range. In subsequent cohorts, the initial dose is also subject to change based upon
the results of the interim analysis in previous cohorts.

Key Inclusion Criteria:

1. Males or non-pregnant females from birth to <18 years of age

2. Receiving standard of care antibiotic therapy for suspected or diagnosed
Gram-negative infection or for peri-operative prophylaxis

3. Groups 1-4: Calculated creatinine clearance rate (CLCR) ≥ 80 ml/min/1.73m2 at
baseline

4. Group 5: CLCR ≥ 50 ml/min/1.73m2 at baseline

5. Group 6: CLCR ≥ 20 ml/min/1.73m2 at baseline

Key Exclusion Criteria:

1. Known allergy/hypersensitivity to any β-lactam antibacterial

2. History of clinically significant renal, hepatic, or hemodynamic instability

3. Planned use of cardiopulmonary bypass or dialysis

4. Planned blood transfusion within 24 hours of study drug administration

5. Clinically significant abnormal laboratory test results not related to the underlying
infection

6. Receipt of piperacillin/tazobactam within 24 hours of study drug administration

7. Likely to be at risk of hemodynamic disturbance following collection of the required
PK blood samples