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

Inclusion Criteria:

1. Participant's parent(s) or legally authorized representative(s) (LAR) provideswritten informed 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 board/independent ethics committee [IRBs/IECs] orbe consistent with local legal requirements)

3. Hospitalized participant is 3 months to < 18 years of age at the time writteninformed consent/assent is obtained for the multiple-dose phase. Hospitalizedparticipant is 3 months to < 12 years of age at the time written informedconsent/assent is obtained for the single-dose phase.

4. Single-dose phase: Participant has a suspected or confirmed infection type (including but not limited to cUTI, complicated intra-abdominal infections [cIAI],pneumonia, HABP/VABP, and sepsis or bloodstream infections [BSI]) that requireshospitalization for treatment with IV antibiotics. Multiple-dose phase: Participant has a suspected or confirmed cUTI, HABP, or VABPthat requires hospitalization for treatment with 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 (including condom, diaphragm, or cervical cap) with spermicide or agrees to use ahighly effective method of contraception (including contraceptive implant,injectable contraceptive, combination oral contraceptive, or an intrauterine [IUD]contraceptive device) from Screening up to 28 days after administration of the lastdose of cefiderocol.

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 (forexample, meningitis, brain abscess, shunt infection) or osteomyelitis (which wouldrequire prolonged 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 the Schwartz equation if ≥ 3months to < 1 year of age and modified Bedside Schwartz equation if ≥ 1 to < 18years of age) of < 60 milliliter (mL)/ minute (min)/1.73 square meters (m^2)² atScreening . Multiple-dose phase: Participant has an eGFR (based on the Schwartz equation if ≥ 3months to < 1 year of age and modified Bedside Schwartz equation if ≥ 1 to < 18years of age) of < 15 mL/min/1.73 m² at Screening.

6. Participant has end-stage renal disease (ESRD), is on hemodialysis (HD), orreceiving continuous 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 with 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.