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Study on the Effectiveness and Safety of Follitropin Delta for Men with Unexplained Infertility

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the treatment of idiopathic male infertility, which is a condition where men experience unexplained difficulties in conceiving a child due to reduced semen quality. The trial will evaluate the effectiveness and safety of a medication called follitropin delta, marketed under the name REKOVELLE. This medication is administered as a solution for injection using a pre-filled pen. The study will compare the effects of follitropin delta with a placebo, which is an inactive treatment, to determine its impact on the chances of achieving a spontaneous pregnancy in the female partners of the participants.

The purpose of the study is to investigate whether follitropin delta can improve the likelihood of spontaneous pregnancy in couples where the male partner has idiopathic infertility. Participants in the study will receive either the active medication or a placebo. The study will be conducted over a period of several months, during which the participants will be monitored for any changes in their condition and the occurrence of pregnancy in their partners. The trial aims to provide valuable insights into the potential benefits of follitropin delta for men with this type of infertility.

Throughout the study, participants will receive regular follow-ups to assess their response to the treatment and to ensure their safety. The main goal is to observe whether the use of follitropin delta leads to a higher rate of spontaneous pregnancies compared to the placebo. This research could offer new hope for couples struggling with unexplained infertility by potentially providing an effective treatment option for improving fertility outcomes.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomisation

    Upon joining the study, the participant is randomly assigned to receive either the active treatment, follitropin delta, or a placebo. This process is double-blind, meaning neither the participant nor the researchers know which treatment is being administered.

  2. Step 2

    Treatment administration

    The participant receives follitropin delta or placebo through a subcutaneous injection. The medication is provided in a pre-filled pen containing 72 micrograms per 2.16 mL solution.

    The injections are administered according to the schedule provided by the study team. The exact dosage and frequency are determined based on the study protocol.

  3. Step 3

    Monitoring and follow-up

    Throughout the trial, the participant's health and response to the treatment are monitored. This includes regular assessments of sperm count, motility, and volume, as well as hormone levels such as follicle-stimulating hormone (FSH), luteinising hormone (LH), and testosterone.

    The participant is required to provide information on their female partner's pregnancy status, including any positive urine pregnancy tests and ultrasound documentation.

  4. Step 4

    Evaluation of primary endpoint

    The primary goal of the trial is to determine if the treatment increases the chance of spontaneous pregnancy in the participant's female partner within 9 months after randomisation. A spontaneous pregnancy is confirmed by the presence of a gestational sac with a fetal heartbeat via ultrasound.

  5. Step 5

    Trial completion

    The trial is expected to conclude by July 15, 2026. At the end of the study, the data collected will be analyzed to assess the efficacy and safety of follitropin delta in treating idiopathic male infertility.

Who can join the trial?

14 criteria

  • Have a history of infertility with your current partner for 12 to 60 months.
  • Agree to provide information about your female partner's positive pregnancy tests, ultrasound results, delivery, and baby health.
  • Your current partner must be a pre-menopausal woman aged 18 to 35 years.
  • Your partner should have regular menstrual cycles lasting 21 to 35 days.
  • Your partner should not have a history or current condition of pelvic inflammatory disease, endometriosis (a condition where tissue similar to the lining inside the uterus grows outside it) stage II-IV, or have had tubal ligation (a procedure to block the fallopian tubes).
  • Your partner must agree not to seek infertility treatment outside of this trial for 9 months after you join the study.
  • You must be a man aged 18 to 50 years.
  • Your total sperm count should be between 5 and 39 million, confirmed by two samples taken at least 2 weeks apart before joining the study.
  • Your total sperm motility (movement) should be at least 10%, confirmed by two samples taken at least 2 weeks apart before joining the study.
  • Your semen volume should be at least 1.4 mL, confirmed by two samples taken at least 2 weeks apart before joining the study.
  • Your serum follicle-stimulating hormone (FSH) levels should be between 1.5 and 8.0 IU/L, measured at a central laboratory during screening. FSH is a hormone important for sperm production.
  • Your serum luteinising hormone (LH) levels should be between 1.2 and 7.5 IU/L, measured at a central laboratory during screening. LH is a hormone that helps regulate testosterone production.
  • Your serum total testosterone levels should be at least 300 ng/dL (or 10.4 nmol/L), measured at a central laboratory during screening. Testosterone is a hormone important for male reproductive health.
  • Agree to have regular intercourse with your current female partner with the goal of natural conception within 9 months after joining the study.

Who cannot join the trial?

5 criteria

  • Men who do not have idiopathic infertility. This means infertility with no known cause.
  • Men who do not have oligoasthenozoospermia. This is a condition where there are fewer sperm than normal, and they move less effectively.
  • Men who are not within the specified age range for the study.
  • Men who are part of a vulnerable population, which means they might need special protection or care.
  • Men who do not meet other specific health or medical criteria set by the study.
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Investigated drugs

FE 999049 is a medication being studied for its potential to help men with idiopathic infertility. The goal of using this medication is to increase the likelihood of spontaneous pregnancy in their female partners. This means that the medication is being tested to see if it can improve the chances of a couple becoming pregnant without the need for assisted reproductive technologies.

What is already known about the treatment

FE 999049 – This medication is administered as an injection and is currently being studied in clinical trials for its potential to treat idiopathic male infertility, including conditions like oligoasthenozoospermia. It is not yet widely recognized in medical literature as a standard treatment, as it is still under investigation. The main therapeutic indication is to improve fertility in men, thereby increasing the chance of spontaneous pregnancy in their female partners. The mechanism of action at the molecular level involves enhancing sperm production and quality, although the exact details are still being researched. It is classified pharmacologically as a fertility agent.

Investigated diseases

Idiopathic Male Infertility – This condition refers to infertility in men where the cause is unknown, despite thorough medical evaluation. It is characterized by the inability to conceive a child with a female partner after a year of regular, unprotected intercourse. The term "idiopathic" indicates that the infertility cannot be attributed to any identifiable medical issue. A common manifestation of this condition is oligoasthenozoospermia, which involves a low sperm count and reduced sperm motility. The progression of idiopathic male infertility can vary, with some men experiencing changes in sperm quality over time. However, the underlying cause remains elusive, making it challenging to predict changes in fertility status.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508430-34-00Estimated enrolment400 patientsSponsorFerring Pharmaceuticals A/S

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

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