PK Study of Single-Dose ZTI-01 in Children (<12 Years of Age)

Based on pre-dose weight on Day -1, subjects weighing within the 3rd to < 97th percentile
based on age - will receive a single, weight adjusted dose of ZTI-01 via continuous IV
infusion or syringe pump over a 1- hour (+10 min) period. Pediatric subjects participating in
this study will be assigned to one of three cohorts based on age:

Cohort 1: ≥ 6 years to <12 years (n=6 PK evaluable subjects) Cohort 2: ≥ 2 years to <6 years
(n=6 PK evaluable subjects)

Cohort 3: Birth to < 2 years (n=9 PK evaluable subjects), split into 3 subgroups:

(3a) Birth (defined as full term: 37 weeks of gestations or greater) to < 3 mos, (3b) ≥ 3 mos
to < 6 mos, (3c) ≥ 6 mos to < 24 months

Cohorts 1 and 2 will be enrolled first with safety and PK data evaluated before enrolling the
youngest Cohort 3. Blood for fosfomycin concentration measurement will be collected
throughout the study. Safety will be assessed by monitoring adverse and serious adverse
events based on medical history, vital signs, ECG, laboratory assessment and physical
examination.

Inclusion Criteria:

- Signed consent/assent

- Male or female subjects aged from Birth (defined as full term: 37 weeks of gestation
or greater) but less than 12 years old

- Hospitalized, currently receiving antibacterial treatment for confirmed or suspected
bacterial infection

- If of reproductive potential, agrees to avoid becoming pregnant or impregnating a
partner from the time of consent through 24 hours after completion of study drug
administration

- Has sufficient intravascular access to receive study drug through peripheral or
central line

Exclusion Criteria:

- Has history of known allergy, hypersensitivity, or intolerance to oral or intravenous
fosfomycin

- Screening serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >3x
ULN or total bilirubin >2x ULN

- Female is post onset of menarche and currently pregnant, or breast feeding, or has a
positive serum β-human chorionic gonadotropin (β-hCG) pregnancy test

- Impaired renal function at screening based on the Revised Schwartz Formula using
actual body height

- Known infection with immunodeficiency virus (HIV), hepatitis C virus, or hepatitis B
virus

- Other laboratory tests, obtained as standard of care, that are outside the normal
limits, considered by the Investigator, to be clinically significant

- Have surgery scheduled during collection period of plasma for fosfomycin
concentrations

- Weighs outside of the 3rd to less than <97th percentile based on age

- History of a seizure disorder requiring ongoing treatment with anticonvulsive therapy
or prior treatment with anti-convulsive therapy within the last 3 years

- Is currently participating in or has participated in an interventional clinical trial
with an investigational compound or device within 30 days or 5 half-lives, or twice
the duration of the biological effect of any drug (whichever is longer) of
administration of the study drug

- Has enrolled previously in the current trial or has received ZTI-01 or fosfomycin (IV
or oral) for any other reason within the last 30 days

- Is expected to survive less than 72 hours after completion of study drug
administration

- Plans to use cardiopulmonary bypass, extracorporeal membrane oxygenation,
hemodialysis, or peritoneal dialysis during the study

- Clinically significant abnormalities on the ECG

- Planned blood transfusion within 24 hours of study drug administration or expected
before the end of the PK sampling, or has had significant blood loss (≥5% of total
blood volume) within 4 weeks before the screening visit

- Any condition that, in the opinion of the PI, would compromise the safety of the
subject or the quality of the data

- Subject or caregiver/parent is unable or unwilling to adhere to the study-specified
procedures and restrictions