Study to Evaluate the Effect of a Single Oral Dose of Zoliflodacin 3 g on Testicular Function in … (NCT07640477) | Clinical Trial Compass
Not Yet RecruitingPhase 4
Study to Evaluate the Effect of a Single Oral Dose of Zoliflodacin 3 g on Testicular Function in Healthy Adult Men
Germany, United Kingdom200 participantsStarted 2026-10
Plain-language 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)
Who can participate
Age range
18 Years – 45 Years
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Man with good general health status, as determined by medical history, physical examination, screening laboratory tests, vital signs (including temperature), and clinical judgment
. Age 18 to 45 years at informed consent
. Weight ≥35 kg at Screening
. Laboratory results at Screening, including FSH, LH, and total testosterone, within laboratory reference ranges
. Semen parameters for each semen sample collected during Screening meeting the following criteria (WHO 2021):
. 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
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Sperm concentration
Timeframe: Week 13 (and potentially week 26)
Trial details
NCT IDNCT07640477
SponsorGlobal Antibiotics Research and Development Partnership
. Willingness to participate and comply with all aspects of the trial through the entire trial period
Exclusion criteria
. 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
. Prior diagnosis of male impaired fertility (including reduced fertility)
. History of antisperm antibodies
. History of radiation to the testicles
. History of clinically significant trauma to or surgery on the scrotum or testicles, including vasectomy
. Known hypersensitivity to zoliflodacin or formulation excipients
. Disorders of sperm transport including, but not limited to, retrograde ejaculation and immotile cilia syndrome
. Sexual dysfunction of a nature that would prevent sperm collection in accordance with the protocol requirements (phosphodiesterase inhibitor use is permitted)