Ongoing Clinical Trials for Male Infertility
Four clinical trials are currently recruiting participants to investigate new treatment approaches for male infertility, including conditions such as low sperm count, poor sperm movement, and unexplained fertility problems. These studies are taking place across several European countries and are testing different medications that may help improve fertility outcomes for affected couples.
Clinical trial locations
- Belgium
- Denmark
- Germany
- Italy
- Spain
- Sweden
Study of vaginal pentoxifylline gel PKB171 compared to placebo in couples with mild male infertility due to low sperm count or poor sperm movement
This trial is investigating a novel approach to treating mild fertility issues in couples where the male partner has either a low sperm count (oligospermia) or poor sperm movement (asthenozoospermia). The study is taking place in Spain.
What is being tested: The trial examines PKB171, a vaginal gel containing pentoxifylline that is applied after sexual intercourse. This represents a non-invasive treatment option that the female partner uses vaginally, rather than the male partner taking medication directly.
Who can participate: The study is looking for couples who have been trying to conceive for more than 6 months but less than 2 years. Female partners should be between 18 and 38 years old with regular menstrual cycles and normal ovarian function. Male partners should be between 18 and 50 years old with semen analysis showing slightly reduced sperm concentration (more than 11 million per milliliter) and less than 42% total sperm movement, with at least 2% normal sperm forms.
Who cannot participate: Couples are excluded if the female partner is over 40 years old, has blocked fallopian tubes, previous failed IVF treatments, severe endometriosis, recurrent miscarriages, or certain uterine conditions. Either partner cannot participate if they have active genital infections, uncontrolled chronic conditions, genetic disorders affecting fertility, or if either partner currently smokes. The male partner cannot have complete absence of sperm or be taking medications that affect sperm quality.
Study design: This is a double-blind study, meaning neither the couples nor their doctors will know whether they receive the active PKB171 gel or a placebo gel. The gel is used after intercourse during fertile days for up to three monthly cycles. Pregnancy tests are performed to check for pregnancy, and if positive, an ultrasound confirms clinical pregnancy by detecting the baby’s heartbeat between weeks 6 and 8. If pregnancy occurs, monitoring continues through week 20 and until delivery.
Study on Denosumab for Improving Semen Quality in Men with Non-Obstructive Azoospermia
This Danish trial focuses on a severe form of infertility called non-obstructive azoospermia, where men have no sperm in their semen but without any physical blockage in the reproductive tract. The study investigates whether a medication called Denosumab might help produce sperm.
What is being tested: Denosumab is a medication normally used to treat bone-related conditions. Researchers are exploring whether it might also help improve sperm production in men with this specific type of infertility. The medication is given as a single injection under the skin at a dose of 60 mg.
Who can participate: Men between 18 and 60 years old who have confirmed azoospermia (no sperm in semen) based on at least two semen tests, with normal semen volume but reduced testicle size (15 milliliters or less on both sides). Participants must have no known blockages and must have a blood level of AMH (Anti-Müllerian Hormone) of at least 28 picomoles per liter.
Who cannot participate: The study excludes individuals who are not male or who fall outside the specified age range, as well as those considered part of vulnerable populations.
Study design: After enrollment and initial assessment including baseline semen samples and hormone measurements, participants receive the Denosumab injection. Follow-up assessments occur on days 14 and 80, involving semen samples and blood tests to monitor hormone changes. The final assessment on day 90 includes another semen sample and possibly a testicular biopsy to identify any presence of sperm and compare with previous data.
Study on Denosumab for Improving Semen Quality in Men with Infertility
This Danish study also investigates Denosumab but focuses on men with oligospermia, a condition characterized by low but present sperm count, rather than complete absence of sperm.
What is being tested: Like the previous trial, this study examines whether Denosumab can improve sperm quality. However, this trial uses a placebo-controlled design, meaning some participants will receive the active medication while others receive an inactive placebo injection. This helps researchers determine whether any improvements are truly due to the medication.
Who can participate: Men aged 18 to 60 years with significantly reduced sperm production, specifically those with sperm concentration less than 2 million per milliliter. Participants must also have a serum AMH level greater than 30 picomoles per liter.
Who cannot participate: The study excludes individuals who are not male, those outside the specified age range, and members of vulnerable populations who may have limited ability to provide informed consent or are at higher risk of harm.
Study design: After initial eligibility confirmation and baseline semen sample collection, participants receive either a 60 mg Denosumab injection or placebo under the skin. Follow-up visits monitor health status and hormone levels. A semen sample is collected on day 80 to evaluate changes in sperm concentration and quality. Final assessments review reproductive hormone changes, overall semen quality, and track any spontaneous pregnancies that occur during the trial.
Study on the Effectiveness and Safety of Follitropin Delta for Men with Unexplained Infertility
This international trial, conducted across Denmark, Spain, Sweden, Italy, Germany, and Belgium, investigates treatment for idiopathic (unexplained) infertility in men. The study focuses on whether medication can improve the chances of spontaneous pregnancy in couples affected by this condition.
What is being tested: The trial evaluates follitropin delta (marketed as REKOVELLE), administered as a subcutaneous injection using a pre-filled pen. The study compares this active medication with a placebo to determine whether it increases the likelihood of achieving pregnancy naturally without assisted reproductive technologies.
Who can participate: Men aged 18 to 50 years with a history of infertility with their current partner for 12 to 60 months. Participants must have a total sperm count between 5 and 39 million (confirmed by two samples at least 2 weeks apart), total sperm motility of at least 10%, and semen volume of at least 1.4 mL. Hormone levels must fall within specific ranges: FSH between 1.5 and 8.0 IU/L, LH between 1.2 and 7.5 IU/L, and total testosterone at least 300 ng/dL. The female partner must be 18 to 35 years old with regular menstrual cycles and no history of conditions like endometriosis or pelvic inflammatory disease. Couples must agree to regular intercourse with the goal of natural conception and not seek other fertility treatments for 9 months.
Who cannot participate: Men with identified causes of infertility (not idiopathic), those outside the specified age range, members of vulnerable populations, or those not meeting specific health criteria. Female partners who have had tubal ligation or have certain reproductive conditions are also excluded.
Study design: This is a double-blind, randomized trial where participants are assigned to receive either follitropin delta or placebo without knowing which they receive. Regular monitoring tracks sperm count, motility, volume, and hormone levels throughout the study. The primary goal is to determine if treatment increases the chance of spontaneous pregnancy within 9 months, confirmed by ultrasound showing a gestational sac with fetal heartbeat. The trial is expected to conclude in July 2026.
Summary
These four clinical trials represent diverse approaches to addressing different types and severities of male fertility problems. A notable geographic concentration exists in Denmark, which hosts three of the four studies, suggesting strong research activity in this field within that country. The trials span multiple other European nations including Spain, Sweden, Italy, Germany, and Belgium, providing broad access to these experimental treatments.
Two trials focus on Denosumab, a medication originally developed for bone conditions, investigating its potential application in fertility treatment for both severe cases (complete absence of sperm) and moderate cases (very low sperm count). The follitropin delta trial takes a broader international approach, examining unexplained infertility across six countries. Perhaps most innovative is the PKB171 study, which uniquely tests a vaginal gel applied by the female partner rather than medication taken by the male partner, representing a novel treatment delivery method.
The trials employ rigorous scientific methods including placebo controls and double-blind designs where applicable, which helps ensure reliable results. Participants in these studies gain access to experimental treatments that may offer hope where conventional options have been limited, while contributing valuable data to advance understanding and treatment of male fertility challenges.
