Testicular AbnominaliesPhase 4NCT07640477
Study to Evaluate the Effect of Zoliflodacin on Testicular Function in Healthy Adult Men
A Phase 4 study testing Zoliflodacin in people with Testicular Abnominalies, run by Global Antibiotics Research and Development Partnership at 2 sites in 2 countries.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 to 45 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Testicular Abnominalies
- What is being tested?
- Zoliflodacin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 200 participants
- Where
- 2 sitesin 2 countries
- Study dates
- Oct 2026to Nov 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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):
- sperm concentration ≥16 million/mL
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- semen volume ≥1.4 mL
- total sperm per ejaculate ≥39 million
- progressive motility ≥ 30%
- sperm morphology : normal forms ≥4%
- 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
- Provision of written informed consent
- Willingness to participate and comply with all aspects of the trial through the entire trial period
Who cannot join
- 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
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- 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)
- Uncontrolled thyroid dysfunction (e.g., untreated hypothyroidism or hyperthyroidism)
- 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
- History of major surgery or trauma within 4 weeks before Day 1 or anticipated need for major surgery during the trial
- Febrile illness within 4 weeks before Screening
- Clinically significant urinary tract infection, prostatitis, epididymitis, or STI diagnosed or treated within 4 weeks before Screening
- Genitourinary sign or symptom indicative of a current STI (urethral discharge, dysuria, or genital lesion) at Screening or Day 1
- Positive nucleic acid amplification test (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 or for any other pathogen tested according to the trial site standards for blood and semen handling
- 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
- 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
- Current tobacco use of ≥1 pack/day or equivalent
- Current alcohol use >5 units per week
- Known or suspected drug abuse
- A positive drug or alcohol screen result at Screening or Day 1 visit
- Participation in an interventional clinical study within 30 days or 5 half-lives of the study drug, whichever is longer, before Day 1 -
Trial locations and contacts
2 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
2 sites in 2 countries
About this study
Official title: 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
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.
Read more
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)
- Conditions
- Testicular Abnominalies
- Being tested
- Zoliflodacin, Placebo
- Keywords
- Testicular toxicities
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ZoliflodacinDrug
Oral suspension of Zoliflodacin 3g
PlaceboDrug
Oral suspension of matching placebo
| Study group | Role | What they receive |
|---|---|---|
| Zoliflodacin | Experimental | Not described Receives: Drug: Zoliflodacin |
| Placebo | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sperm concentration
Percentage of participants with a ≥50% decrease from baseline in sperm concentration (million/mL) at Week 13
Measured: Week 13 (and potentially week 26)
Secondary outcomes (7)
Semen Volume
Change in semen volume (in mL)
Measured: At baseline and week 13
Sperm count
Total sperm count per ejaculate (million)
Measured: At Baseline and week 13
Progressive mobility
Sperm exhibiting active forward movement (μm/s)
Measured: At Baseline and Week 13
Morphology
Evaluated using Tygerberg Strict Criteria (%)
Measured: At baseline and week 13
Serum Hormones (LH)
Change in luteinizing hormone (LH), shift analysis relative to reference ranges
Measured: At Baseline and Week 13
Serum hormones (FSH)
Change in Follicle Stimulating Hormone (FSH), shift analysis relative to reference ranges
Measured: At Baseline and Week 13
Serum Hormones (Testosterone)
Change in Testosterone, shift analysis relative to reference ranges
Measured: At baseline and week 13
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2026
- Study startOct 2026 (estimated)
- Primary completionNov 2027 (estimated)
- Study completionNov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Testicular AbnominaliesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Screening
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, double blind, placebo controlled
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Global Antibiotics Research and Development Partnership
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07640477
- Sponsor's protocol ID
- STI_PMR_Zoli007
- Status last verified
- Jun 2026
- First submitted
- 1 Jun 2026
- Last updated
- 26 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07640477
- Acronym / sponsor ID
- STI_PMR_Zoli007
- Conditions
- Testicular Abnominalies
- Keywords
- Testicular toxicities
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Global Antibiotics Research and Development PartnershipUniversity, hospital or other
- Study start
- Oct 2026 (estimated)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Nov 2027 (estimated)
- First posted
- 10 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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)
Study design
- Primary purpose
- Screening
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized, double blind, placebo controlled
| Arm | Type | Receives |
|---|---|---|
| Zoliflodacin | Experimental | Drug: Zoliflodacin |
| Placebo | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (13 listed)
- 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):
Key exclusion criteria (32 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ZoliflodacinOral suspension of Zoliflodacin 3g | Drug | Zoliflodacin |
| PlaceboOral suspension of matching placebo | Drug | Placebo |
Primary outcome
Sperm concentration
Time frame: Week 13 (and potentially week 26)
Percentage of participants with a ≥50% decrease from baseline in sperm concentration (million/mL) at Week 13
7 secondary outcomes
Semen Volume
Time frame: At baseline and week 13
Sperm count
Time frame: At Baseline and week 13
Progressive mobility
Time frame: At Baseline and Week 13
Morphology
Time frame: At baseline and week 13
Serum Hormones (LH)
Time frame: At Baseline and Week 13
Serum hormones (FSH)
Time frame: At Baseline and Week 13
Serum Hormones (Testosterone)
Time frame: At baseline and week 13
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Oct 2026.
- FDA Guidance for industryLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Zoliflodacin in people with Testicular Abnominalies, run by Global Antibiotics Research and Development Partnership at 2 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 32 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 26 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jovana Albig, MD (+41 22 555 19 90, info@gardp.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sperm concentration (time frame: Week 13 (and potentially week 26)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Oct 2026.