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Study to Evaluate the Effect of a Single Oral Dose of Zoliflodacin 3 g on Testicular Function in Healthy Adult Men

A Randomized, Double-blind, Placebo-controlled Study to Evaluate the Effect of a Single Oral Dose of Zoliflodacin 3 g on Testicular Function in Healthy Adult Men

Status
Not yet recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07640477
Enrollment
200
Registered
2026-06-10
Start date
2026-10-01
Completion date
2027-11-01
Last updated
2026-06-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Testicular Abnominalies

Keywords

Testicular toxicities

Brief summary

This study is a randomized, double-blind, placebo-controlled clinical trial to evaluate the effect of zoliflodacin on testicular function in healthy adult men. Participants will be screened within 21 days before randomization (Day 1), including collection of 2 semen samples (each collected after a ≥48 hours and ≤7 days ejaculation-free period). Approximately 220 participants who provide written informed consent and meet all inclusion and no exclusion criteria will be enrolled and randomized in a 1:1 fashion to receive a single dose of either zoliflodacin 3 g or placebo administered as an oral suspension on Day 1. Each participant will be contacted by telephone at Week 1 and at Week 7 post dosing to review adverse events (AEs), concomitant medications and procedures, and genitourinary symptoms. Each participant will return to the trial site at Week 13 for collection of 2 semen samples (each collected after a ≥48 hours and ≤7 days ejaculation-free period). A serum sample will also be collected for hormone testing (luteinizing hormone \[LH\], follicle-stimulating hormone \[FSH\], and total testosterone) at Week 13 to support biological interpretation of any decrease in sperm concentration. Participants who do not have a ≥50% decrease from baseline in sperm concentration at Week 13 will complete the trial at Week 13 (end of trial). Participants with a ≥50% decrease from baseline in sperm concentration at Week 13 will return to the trial site at Week 26 for collection of 2 semen samples (independent ejaculates, each collected after a ≥48 hours and ≤7 days ejaculation-free period) for evaluation of the reversibility of the Week 13 finding, following completion of a one additional spermatogenic cycle post completion of dosing/drug exposure (FDA 2018) (end of trial). All Adverse Events, medications, and procedures will be recorded from the signing of the informed consent form (ICF) through the end-of-trial visit (Week 13, Week 26, or Early Termination)

Interventions

Oral suspension of Zoliflodacin 3g

DRUGPlacebo

Oral suspension of matching placebo

Sponsors

Global Antibiotics Research and Development Partnership
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SCREENING
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Intervention model description

Randomized, double blind, placebo controlled

Eligibility

Sex/Gender
MALE
Age
18 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

1. Man with good general health status, as determined by medical history, physical examination, screening laboratory tests, vital signs (including temperature), and clinical judgment 2. Age 18 to 45 years at informed consent 3. Weight ≥35 kg at Screening 4. Laboratory results at Screening, including FSH, LH, and total testosterone, within laboratory reference ranges 5. Semen parameters for each semen sample collected during Screening meeting the following criteria (WHO 2021): * sperm concentration ≥16 million/mL * semen volume ≥1.4 mL * total sperm per ejaculate ≥39 million * progressive motility ≥ 30% * sperm morphology : normal forms ≥4% 6. Willingness to use a highly effective form of contraception with female sexual partners of reproductive potential for 3 months after the last study drug dose 7. Provision of written informed consent 8. Willingness to participate and comply with all aspects of the trial through the entire trial period

Exclusion criteria

1. History of male reproductive health issues including, but not limited to, known hypothalamic-pituitary disorders (e.g., pituitary macroadenomas, pituitary infarction, hyperprolactinemia, panhypopituitarism), primary hypogonadism (e.g., cryptorchidism, Klinefelter's syndrome), Grade III varicocele, testicular torsion, orchitis, unilateral orchiectomy, or prostate gland pathology 2. Prior diagnosis of male impaired fertility (including reduced fertility) 3. History of antisperm antibodies 4. History of radiation to the testicles 5. History of clinically significant trauma to or surgery on the scrotum or testicles, including vasectomy 6. Known hypersensitivity to zoliflodacin or formulation excipients 7. Disorders of sperm transport including, but not limited to, retrograde ejaculation and immotile cilia syndrome 8. Sexual dysfunction of a nature that would prevent sperm collection in accordance with the protocol requirements (phosphodiesterase inhibitor use is permitted) 9. Uncontrolled thyroid dysfunction (e.g., untreated hypothyroidism or hyperthyroidism) 10. Any chronic medical or psychiatric condition that, in the opinion of the investigator, may harm the participant or make the participant unsuitable for the trial or would prevent compliance with the trial protocol procedures 11. History of major surgery or trauma within 4 weeks before Day 1 or anticipated need for major surgery during the trial 12. Febrile illness within 4 weeks before Screening 13. Clinically significant urinary tract infection, prostatitis, epididymitis, or STI diagnosed or treated within 4 weeks before Screening 14. Genitourinary sign or symptom indicative of a current STI (urethral discharge, dysuria, or genital lesion) at Screening or Day 1 15. Positive nucleic acid amplification test (NAAT) result for N gonorrhoeae at Screening 16. Positive serologic test for HIV-1 or HIV-2 antibody, hepatitis B surface antigen, or hepatitis C antibody or for any other pathogen tested according to the trial site standards for blood and semen handling 17. Use within 13 weeks before Screening of or anticipated need during the trial for a medication known to affect spermatogenesis or reproductive hormone regulation including, but not limited to, the following medications: * testosterone * gonadotropin analogues * anabolic steroids * antiandrogens (e.g., spironolactone, finasteride, dutasteride, ketoconazole) * 5-α reductase inhibitors * α-1 blockers * chemotherapeutic agents * chronic (≥90 days) use of opioids * other hormone-modulating medications 18. Use within 14 days before Day 1 of a moderate or strong cytochrome P450 isoenzyme 3A4 (CYP3A4) inducer (e.g., rifampin, carbamazepine, phenytoin, St. John's Wort) or anticipated need for moderate or strong CYP3A4 inducers from Day 1 to Day 3 19. Current tobacco use of ≥1 pack/day or equivalent 20. Current alcohol use \>5 units per week 21. Known or suspected drug abuse 22. A positive drug or alcohol screen result at Screening or Day 1 visit 23. Participation in an interventional clinical study within 30 days or 5 half-lives of the study drug, whichever is longer, before Day 1 -

Design outcomes

Primary

MeasureTime frameDescription
Sperm concentrationWeek 13 (and potentially week 26)Percentage of participants with a ≥50% decrease from baseline in sperm concentration (million/mL) at Week 13

Secondary

MeasureTime frameDescription
Semen VolumeAt baseline and week 13Change in semen volume (in mL)
Sperm countAt Baseline and week 13Total sperm count per ejaculate (million)
Progressive mobilityAt Baseline and Week 13Sperm exhibiting active forward movement (μm/s)
MorphologyAt baseline and week 13Evaluated using Tygerberg Strict Criteria (%)
Serum Hormones (LH)At Baseline and Week 13Change in luteinizing hormone (LH), shift analysis relative to reference ranges
Serum hormones (FSH)At Baseline and Week 13Change in Follicle Stimulating Hormone (FSH), shift analysis relative to reference ranges
Serum Hormones (Testosterone)At baseline and week 13Change in Testosterone, shift analysis relative to reference ranges

Countries

Germany, United Kingdom

Contacts

CONTACTJovana Albig, MD
info@gardp.org+41 22 555 19 90

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 11, 2026