A Study to Assess the Safety, Tolerability, and Pharmacokinetics of Single and Multiple Doses of Cefiderocol in Hospitalized Pediatric Participants

Inclusion Criteria:

1. Participant's parent(s) or legally authorized representative (LAR) provides writteninformed consent in accordance with regional and country-specific laws andregulations.
2. Participant provides written informed assent, when feasible (age of assent to bedetermined by institutional review boards/independent ethics committees [IRB's/IEC's]or be consistent with local legal requirements).
3. Hospitalized participant is 3 months to <18 years of age at the time written informedconsent/assent is obtained for the single-dose phase. Hospitalized participant is 3months to <12 years of age at the time written informed consent/assent is obtained forthe multiple-dose phase. Premature babies will not be restricted, but the participantmust have an adjusted or postnatal age of 3 months.
4. Participant has a suspected or confirmed infection (including but not limited tocomplicated urinary tract infection [cUTI], complicated intra-abdominal infection [cIAI], hospital-acquired pneumonia [HAP] /ventilator-acquired pneumonia [VAP],sepsis, or bloodstream infections [BSI]) that requires hospitalization for treatmentwith IV antibiotics.
5. If participant is a sexually active female of childbearing potential and has reachedmenarche or Tanner stage 3, participant agrees to use barrier contraception (includingcondom, diaphragm, or cervical cap) with spermicide or agrees to use a highlyeffective method of contraception (including contraceptive implant, injectablecontraceptive, combination oral contraceptive, or an intrauterine [IUD] contraceptivedevice) from Screening up to 28 days after administration of the last dose ofcefiderocol.

Exclusion Criteria:

1. Participant has a documented history of any hypersensitivity or allergic reaction toany β-lactam antibiotic (Note: for β-lactams, a history of a mild rash followed byuneventful re-exposure is not a contraindication to enrollment).
2. Multiple-dose only: Participant has an infection caused only by a confirmedGram-positive pathogen.
3. Participant has a suspected or confirmed central nervous system (CNS) infection (eg,meningitis, brain abscess, shunt infection) or osteomyelitis (which would requireprolonged antibiotic therapy).
4. Participant has cystic fibrosis.
5. Single-dose phase: Participant has moderate or severe renal impairment based onestimated glomerular filtration rate (eGFR) (based on Schwartz equation if ≥ 3 monthsto < 1 year of age and modified Bedside Schwartz equation if ≥ 1 to < 18 years of age)of < 60 milliliter (mL) per minute (min)/1.73 ^2² at Screening. Multiple-dose phase: Participant has an eGFR (based on Schwartz equation if ≥ 3 monthsto < 1 year of age and modified Bedside Schwartz equation if ≥ 1 to < 18 years of age)of < 15 mL/min/1.73 ^2² at Screening.
6. Participant has end-stage renal disease (ESRD), is on hemodialysis (HD), or receivingcontinuous venovenous hemofiltration (CVVH).
7. Participant has experienced shock in the prior month or is in shock at the time ofScreening.
8. Participant has severe neutropenia or is severely immunocompromised.
9. Participant has multiorgan failure.
10. Participant has a life expectancy of < 30 days due to severity of a concurrentillness.
11. Participant is a female who has a positive pregnancy test at Screening.
12. Participant is a female who is breastfeeding.
13. Participant has received any other investigational medicinal product (IMP) within 30days.
14. Participant has any condition or circumstance that, in the opinion of theinvestigator, would compromise the safety of the participant or the quality of thestudy data, including acute trauma to the pelvis or urinary tract.
15. Participant is receiving vasopressor therapy at Screening.