Inclusion Criteria

Type of Participant and Disease Characteristics

• Has a diagnosis of proven or suspected NP (including HABP or VABP), as determined by the investigator.
  • Note: The diagnosis of NP does not require a pathogen to be isolated from a diagnostic test.
• Is hospitalized and anticipated to receive a minimum of 8 days of concomitant standard of-care antibiotic therapy for proven or suspected NP. The concomitant standard-of-care antibiotic therapy can have coverage for either gram-positive and/or gram-negative respiratory pathogen(s).
  • Note: Concomitant standard-of-care antibiotics may be stopped before the 8-day minimum at the discretion of the investigator. Participants who discontinue or complete concomitant standard-of-care antibiotic therapy in less than 8 days may also discontinue ceftolozane/tazobactam prior to the minimum duration of 8 days at the investigator’s discretion. However, participants are strongly encouraged to receive a minimum of 8 days of ceftolozane/tazobactam.

Demographics

• Is male or female (not pregnant or nursing) from birth (defined as > 32 weeks gestational age and ≥ 7 days postnatal) to < 18 years of age inclusive, at the time of providing informed consent/assent.

Male Participants

• Contraceptive use by men should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
• Male participants are eligible to participate if they agree to the following during the intervention period and for at least 30 days after the last dose of study intervention:
  • Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent; OR
  • Must agree to use contraception unless confirmed to be azoospermic (vasectomized or secondary to medical cause) (Appendix 5) as detailed below:
    • Agree to use a male condom plus partner use of an additional contraceptive method when having penile-vaginal intercourse with a WOCBP who is not currently pregnant. Note: Men with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile-vaginal penetration.
• Female Participants
  • Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
    • A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies:
      • Is not a WOCBP; OR
      • Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of <1% per year) or be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis), as described in Appendix 5 during the intervention period and for at least 30 days after the last dose of study intervention. The investigator should evaluate the potential for contraceptive method failure (ie, noncompliance, recently initiated) in relationship to the first dose of study intervention;
      • A WOCBP must have a negative highly sensitive pregnancy test (urine or serum as required by local regulations) within 48 hours before the first dose of study intervention.
  • Additional requirements for pregnancy testing during and after study intervention are located in Appendix 2.
  • The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy.

Informed Consent/Assent

• The participant (or legally acceptable representative(s), if applicable) provides documented informed consent/assent for the study.

Additional Categories

• Is able to comply with all study procedures and restrictions for the duration of the study.

Exclusion Criteria:

Medical Conditions

• Has a documented history of any moderate or severe hypersensitivity (or allergic) reaction to any β-lactam antibacterial. Note: A history of a rash while on a β-lactam antibiotic does not automatically exclude a participant (eg, a participant with history of a mild rash followed by uneventful reexposure may be considered for enrollment).
• For Groups 1 through 4, has moderate to severe impairment of renal function, defined as an estimated CrCL <50 mL/min/1.73 m^2 based on the revised Schwartz equation or requirement for peritoneal dialysis, hemodialysis, or hemofiltration. For Group 5, has CrCL < 20 mL/min/1.73 m^2 based on the revised Schwartz equation or requirement for peritoneal dialysis, hemodialysis, or hemofiltration.

Prior/Concomitant Therapy

• Is receiving or is anticipated to receive piperacillin/tazobactam while receiving ceftolozane/tazobactam or has received piperacillin/tazobactam within 24 hours prior to the first dose of ceftolozane/tazobactam.

Prior/Concurrent Clinical Study Experience

• Participation in any clinical study of a therapeutic investigational product within 30 days prior to the first dose of ceftolozane/tazobactam.
• Previous participation in any study of ceftolozane or ceftolozane/tazobactam.

Diagnostic Assessments

• Not applicable.

Other Exclusions

• Has one or more of the following laboratory abnormalities in a specimen obtained at screening:
  • ANC < 1000/mm^3;
  • AST or ALT ≥ 3 × the ULN;
  • Total bilirubin ≥ 2 × the ULN (if 7 to ≤ 28 days of age and breastfeeding, total bilirubin10 mg/dL OR ≥ 2 × ULN).
• Any condition or circumstance that, in the opinion of the investigator, would compromise the safety of the participant or the quality of study data.
• Has any rapidly progressing disease or immediately life-threatening illness including acute hepatic failure or septic shock.
• Has active immunosuppression, including any of the following:
  • HIV infection, with a known CD4 percentage of 5 years of age;
  • Active hematological malignancy;
  • Recipient of solid organ or bone marrow transplants;
  • Currently on immunosuppressive therapy, including cancer chemotherapy;
  • Currently on medications for prevention of transplant rejection;
  • Chronic administration of systemic corticosteroids (defined as the systemic equivalent of ≥2 mg/kg total daily dose of prednisone for participants ≤ 20 kg, or > 40 mg of prednisone per day for participants > 20 kg, administered continuously for more than 14 days in the 30 days prior to the first dose of ceftolozane/tazobactam).
• Is or has an immediate family member (eg, spouse, parent/legal guardian, sibling, or child) who is investigational site or Sponsor staff directly involved with this study.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 8/21/23. Questions regarding updates should be directed to the study team contact.