Pharmacokinetics of Oral Zoliflodacin 3 g in Healthy Lactating Women

An Open-label Study to Evaluate the Pharmacokinetics of a Single Oral Dose of Zoliflodacin 3 g in Milk and Plasma in Healthy Lactating Women

This is a single-arm clinical trial to evaluate the PK profile in breast milk and plasma after a single oral dose of zoliflodacin in healthy lactating women.

Eligible participants who have been actively breastfeeding or expressing milk for at least 4 weeks postpartum will receive a single dose of zoliflodacin administered as an oral suspension with food.

Breast milk and plasma samples will be collected at predefined time points for up to 48 hours after dosing to characterize zoliflodacin concentrations and estimate drug exposure in breast milk and maternal plasma. Participants will temporarily discontinue breastfeeding from study check-in until 72 hours after dosing to avoid infant exposure to zoliflodacin. Breast milk will be expressed using an electronic breast pump and collected according to the study schedule.

Participants will be admitted to the clinical research unit the day before dosing and discharged after completion of the 48-hour PK sampling period. A follow-up visit will be conducted approximately 7 days after dosing to assess safety and tolerability. A lactation consultant will be available throughout the study period and for up to 30 days after dosing, as needed.

Study Overview

• Status: Not yet recruiting
• Conditions: Lactation
• Intervention / Treatment: Drug: Zoliflodacin

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Jovana Albig, MD; Phone Number: +41 22 555 19 90; Email: info@gardp.org

Study Locations

• United States
  • Nevada
    • Las Vegas, Nevada, United States, 89113
      • TrialMed

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Woman with good general health status, as determined by medical history, physical examination, laboratory tests, vital signs, and clinical judgment at Screening and check-in
• Age ≥18 to ≤45 years at the time of signing the informed consent
• Weight ≥50 kg at Screening and check-in
• Given birth to a single, healthy, clinically stable, full-term (37 to 42 weeks' gestation) infant in the past 6 weeks to 24 months before Day 1
• Agrees to not breastfeed her infant from check-in until 72 hours after zoliflodacin administration
• Has well-established lactation (ie, at least 4 weeks postpartum) and is breastfeeding her infant; supplemental infant formula use is allowable, and the extent of use of formula will be documented
• Has confirmed that her breastfed infant is able to feed from a bottle
• Agrees to collect all breast milk from predose through 2 days after the trial drug administration using an electric pump
• Has a negative pregnancy test at Screening and check-in
• Has sufficient venous access to allow for collection of plasma samples
• Agrees to use a highly effective form of contraception (see Section 5.4) with male sexual partners during the trial and for at least 28 days after the zoliflodacin dose
• Agrees to comply with all protocol requirements
• Agrees not to participate in other research trials involving investigational medication or medical devices for the duration of this trial
• Provides written informed consent

Exclusion Criteria:

• History of breast implants, breast augmentation, or breast reduction surgery that, in the investigator's opinion, may have a clinical impact on breast milk expression
• Evidence of acute or chronic condition that, in the investigator's opinion, may have a clinical impact on breast milk expression
• Active mastitis within 30 days before Day 1
• Current breast abscess or cracked/bleeding nipples
• History of inadequate lactation
• Moderate or severe hepatic or renal impairment, or other clinically significant medical condition that, in the investigator's opinion, might affect zoliflodacin PK or participant safety
• Known hypersensitivity to zoliflodacin or formulation excipients
• Positive pregnancy test at Screening or check-in
• Positive NAAT result for N gonorrhoeae at Screening
• Positive serologic test for HIV-1 or HIV-2 antibody, hepatitis B surface antigen, or hepatitis C antibody at Screening. Participants whose results are compatible with prior hepatitis B vaccination (positive hepatitis B surface antibody, negative hepatitis B core antibody, and negative hepatitis B surface antigen) may be included
• Use of zoliflodacin within 30 days before Day 1
• Use of a moderate or strong inducer or inhibitor of CYP3A4, P-glycoprotein, BCRP, or OATP transporters within 14 days or 5 half-lives, whichever is longer, before Day 1
• Consumption of grapefruit, grapefruit juice, or similar citrus fruits (like Seville oranges and pomelos) within 14 days before Day 1
• Current use of tobacco or nicotine-containing products
• Known or suspected drug abuse
• A positive drug or alcohol screen result at Screening or on Day -1
• Participants must not donate blood within 30 days or donate plasma within 7 days before Day 1
• Participation in an interventional clinical trial within 30 days or 5 half-lives of the trial drug, whichever is longer, before Day 1
• Any condition or circumstance that, in the investigator's judgment, may pose a risk to the participant or interfere with protocol adherence (including the 72-hour breastfeeding interruption), assessment of trial objectives, or ability to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Zoliflodacin	Drug: Zoliflodacin; Oral suspension of Zoliflodacin 3g

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Observed Milk Concentration (Cmax) of Zoliflodacin in human milk	Maximum observed concentration of zoliflodacin in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: ng/mL	Through 48 hours post dose
Time to Maximum Observed Concentration (Tmax) of Zoliflodacin in human milk	Time to reach the maximum observed concentration of zoliflodacin in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: hours.	Through 48 hours post-dose.
Terminal Elimination Half-Life (t½) of Zoliflodacin in human Milk	Terminal elimination half-life of zoliflodacin in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: hours.	Through 48 hours post-dose.
Area Under the Concentration-Time Curve From Time Zero to Infinity (AUC₀-∞) of Zoliflodacin in Human Milk	Area under the concentration-time curve from time zero extrapolated to infinity in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: ng·h/mL	Through 48 hours post-dose
Area Under the Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUC₀-last) of Zoliflodacin in Human Milk	Area under the concentration-time curve from time zero to the last quantifiable concentration in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: ng·h/mL.	Through 48 hours post-dose
Area Under the Concentration-Time Curve From Time Zero to 24 Hours (AUC₀-24) of Zoliflodacin in Human Milk	Area under the concentration-time curve from time zero to 24 hours post-dose in human milk following administration of a single oral 3 g dose of zoliflodacin. Unit: ng·h/mL.	24 hours post-dose.
Milk-to-Plasma Ratio for AUC₀-∞ of Zoliflodacin	Ratio of human milk exposure to plasma exposure based on AUC₀-∞ following administration of a single oral 3 g dose of zoliflodacin. Unit: ratio (unitless)	Through 48 hours post-dose.
Milk-to-Plasma Ratio for AUC₀-last of Zoliflodacin	Ratio of human milk exposure to plasma exposure based on AUC₀-last following administration of a single oral 3 g dose of zoliflodacin. Unit: ratio (unitless).	Through 48 hours post-dose.
Milk-to-Plasma Ratio for AUC₀-24 of Zoliflodacin	Ratio of human milk exposure to plasma exposure based on AUC₀-24 following administration of a single oral 3 g dose of zoliflodacin. Unit: ratio (unitless)	24 hours post-dose
Milk-to-Plasma Ratio for Cmax of Zoliflodacin	Ratio of maximum observed concentration in human milk to maximum observed concentration in plasma following administration of a single oral 3 g dose of zoliflodacin. Unit: ratio (unitless).	Through 48 hours post-dose.
Relative Infant Dose (RID) of Zoliflodacin	Estimated relative infant dose of zoliflodacin calculated from measured human milk concentrations and maternal dose following administration of a single oral 3 g dose of zoliflodacin. Unit: %.	Through 48 hours post-dose.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-Emergent Adverse Events (TEAEs)	Number of participants experiencing one or more treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), adverse events leading to discontinuation, and adverse events considered related to zoliflodacin following administration of a single oral 3 g dose.	From dosing through Day 8
Change From Baseline in Systolic Blood Pressure	Change from baseline in systolic blood pressure. Unit: mmHg	Baseline through Day 8
Change From Baseline in Diastolic Blood Pressure	Change from baseline in diastolic blood pressure. Unit: mmHg	Baseline through Day 8
Change From Baseline in Pulse Rate	Change from baseline in respiratory rate. Unit: Breaths/min	Baseline through Day 8
Change From Baseline in Body Temperature	Change from baseline in body temperature. Unit: °C	Baseline through Day 8
Clinically Significant Physical Examination Findings	Number of participants with new or worsened clinically significant abnormalities identified during physical examination following administration of a single oral 3 g dose of zoliflodacin.	Baseline through Day 8

Collaborators and Investigators

• Sponsor: Global Antibiotics Research and Development Partnership

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: October 22, 2026
• First Submitted That Met QC Criteria: November 4, 2026
• First Posted (Actual): November 9, 2026

Study Record Updates

• Last Update Posted (Actual): November 9, 2026
• Last Update Submitted That Met QC Criteria: November 4, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: PHARMACOKINETICS; LACTATION; BREASTFEEDING
• Additional Relevant MeSH Terms: Behavior; Feeding Behavior; Breast Feeding; zoliflodacin
• Other Study ID Numbers: STI_PMR_Zoli008

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No