A Novel Aromatase Inhibitor, Leflutrozole, for Treatment of Non-Obstructive Azoospermia

Starting soon · Phase 1/Phase 2

Conditions studied: Infertility Due to Azoospermia, Infertility, Male

In brief

This clinical interventional study aims to assess whether treatment with with leflutrozole can improve sperm production in infertile men with non-obstructive azoospermia selected by serum anti-mullerian hormone (AMH) or Inhibin B as a positive predictive biomarker.

Key facts

Study ID

NCT07571928

Run by

Martin Blomberg Jensen

People needed

15

Starts

2026-05-01

Expected to finish

2027-08-31

Last updated by the study team

2026-05-06

Who can join

Age: 18 and older, up to 55. Sex: male. Healthy volunteers: not accepted.

You may qualify if…

• Signed informed consent by participant
• Signed informed consent by participant's partner (must just be obtained before the par-ticipant starts treatment at Visit 1), if applicable, regarding blood samples, data collec-tion about fertility treatment as well as pregnancy and pregnancy outcome
• 18-55 years
• Azoospermia verified by at least 2 semen samples, average semen volume >= 1,0 ml with no identifiable sign of obstruction (samples taken at Visit -1 and at Visit 0 prior to confirmation of eligibility and dosing).
• Serum AMH or Inhibin B level above the lower limit of quantification (LLOQ) at screening or within 6 months prior to screening
• Testosterone < 15 nmol/L at screening or within 6 months prior to screening
• Serum estradiol above the lower limit of normal range (48 pmol/L) at screening or within 6 months prior to screening

You may not qualify if…

• Klinefelter or other major genetic conditions including large deletions on sex chromosomes
• Average testis size > 20 mL unless obstruction has been excluded
• TESE procedure < ½ year ago
• LH concentration > 15 IU/L at screening
• Current abuse of steroids
• BMI > 45 kg/m2
• Severe chronic diseases requiring daily medication
• Prior thromboembolic event within the last 24 months
• Cardiovascular event within the last 6 months judged as significant by the investigator
• Osteoporosis requiring medical treatment
• Use of any prescription or non-prescription medication (apart from routine vitamins, occasional use of paracetamol, acetylsalicylic acid, or ibuprofen) which could interfere with pharmacokinetic or pharmacodynamic results, as judged by the investigator, such as:
• Herbal products and non-routine vitamins
• Insulin
• Medication such as systemic corticosteroids, tricyclic antidepressants, and atypical antipsychotics
• Surgery scheduled for the trial duration period, except for minor, non-gastrointestinal surgical procedures at the discretion of the investigator
• Cancer (past or present, except basal cell skin cancer or squamous cell skin cancer), which in the investigator's opinion could interfere with the results of the trial
• Serum prostate specific antigen (PSA) > 3 ng/mL at screening or within 6 months prior to screening
• Hematocrit >50% at screening or within 6 months prior to screening
• Mental incapacity, language barriers or unwillingness to comply with the requirements of the protocol, which may preclude adequate understanding or co-operation during the trial, as judged by the investigator

Where it is running

• Division of Translational Endocrinology, Department of Endocrinology and Internal Medicine, Copenhagen University Hospital Herlev., Herlev, — Herlev, Denmark

Full record on ClinicalTrials.gov

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