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Study of vaginal pentoxifylline gel PKB171 compared to placebo in couples with mild male infertility due to low sperm count or poor sperm movement

Fast replyInvestigationalNo placebo
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What is this trial about?

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

This clinical trial studies the effectiveness of a vaginal gel called PKB171 containing pentoxifylline for couples dealing with mild male factor infertility. Male factor infertility occurs when there are issues with sperm quality, specifically conditions known as oligospermia (low sperm count) and asthenozoospermia (poor sperm movement). The purpose is to determine if using this gel after intercourse can help achieve pregnancy in couples who have been unable to conceive.

The study compares two treatments: the PKB171 gel and a placebo gel. Neither the couples nor their doctors will know which gel is being used. The gel is applied vaginally after sexual intercourse, and couples can participate in the treatment for up to three months. During this time, doctors will monitor whether pregnancy occurs and check for any side effects from using the gel.

The main goal is to see if the gel helps achieve clinical pregnancy, which means a pregnancy where the baby's heartbeat can be detected by ultrasound examination between 6 to 8 weeks of pregnancy. The study will also look at other important factors such as the overall pregnancy rate, pregnancy complications, and the safety of using the gel.

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

    Initial treatment cycle begins

    You will receive either PKB171 gel or placebo gel for vaginal use. The assignment is random and neither you nor the doctor will know which gel you receive.

    The gel should be used after sexual intercourse during your fertile days.

    Each treatment cycle corresponds to your menstrual cycle (25-35 days).

  2. Step 2

    Pregnancy monitoring

    A pregnancy test will be performed to check for a biochemical pregnancy (blood test for pregnancy hormone).

    If the test is positive, an ultrasound will be performed between weeks 6-8 to confirm clinical pregnancy (presence of fetal heartbeat).

  3. Step 3

    Treatment continuation

    If pregnancy is not achieved, you may continue for up to three treatment cycles total.

    Each new cycle follows the same procedure as the first cycle.

  4. Step 4

    Pregnancy follow-up

    If pregnancy occurs, monitoring continues through week 20 to confirm ongoing pregnancy.

    Regular check-ups will monitor your health and the baby's development.

    The follow-up continues until delivery to record pregnancy outcomes.

  5. Step 5

    Safety monitoring

    Throughout the study, you will have regular check-ups to monitor your health.

    Laboratory tests and vital signs will be checked periodically.

    Any side effects or unusual symptoms should be reported during visits.

Who can join the trial?

13 criteria

  • Must sign a written informed consent form before any study procedures begin
  • Couples must have been trying to conceive for more than 6 months but less than 24 months, with regular unprotected sexual intercourse
  • Must be willing and able to follow all study requirements
  • For female participants:
    • Age between 18 and 38 years
    • Regular menstrual cycles lasting 25-35 days (with less than 5 days variation) in the past six months
    • Normal uterine cavity confirmed by transvaginal ultrasound
    • Normal ovarian reserve shown by AMH (Anti-Müllerian Hormone) level of 1 ng/ml or higher
    • Total number of antral follicles (small ovarian follicles) in both ovaries must be 6 or more
    • For male participants:
      • Age between 18 and 50 years
      • Semen analysis showing:
        • Volume: 1 milliliter or more
        • Sperm concentration: more than 11 million per milliliter
        • Less than 42% total sperm movement
        • At least 2% normal sperm forms

Who cannot join the trial?

15 criteria

  • Female partner age over 40 years old
  • Known tubal factor infertility (blocked or damaged fallopian tubes)
  • Previous failed IVF treatments (In Vitro Fertilization - a process where an egg is fertilized outside the body)
  • Current use of hormonal medications that could affect fertility
  • Azoospermia (complete absence of sperm in semen) in male partner
  • Known genetic disorders affecting fertility in either partner
  • Active genital infections in either partner
  • Severe endometriosis (a condition where tissue similar to the uterus lining grows outside the uterus)
  • History of recurrent pregnancy loss (3 or more miscarriages)
  • Presence of uterine fibroids that could affect pregnancy
  • Current smoking habit in either partner
  • Uncontrolled chronic medical conditions (such as diabetes or thyroid disorders)
  • Use of medications known to affect sperm quality
  • Body Mass Index (BMI) above 35 in female partner
  • Known allergies to any components of the study medication
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Investigated drugs

PKB171 is an intravaginal gel designed to be used after sexual intercourse (post-coital). This medication is being studied as a potential treatment for couples experiencing mild male factor infertility. The gel is applied vaginally and aims to improve the chances of achieving pregnancy in cases where male fertility parameters are mildly impaired.

What is already known about the treatment

PKB171 – A novel investigational intravaginal gel medication being studied for couples experiencing mild male factor infertility, specifically in cases of oligospermia (low sperm count) and/or asthenozoospermia (poor sperm motility). The medication is administered post-coitally as a vaginal gel, representing a non-invasive treatment approach in reproductive medicine. While its exact molecular mechanism of action is still under clinical investigation, PKB171 is being evaluated in multicenter, randomized, double-blind trials to assess its potential effectiveness in improving clinical pregnancy rates in couples affected by male fertility issues. The primary outcome measure focuses on achieving clinical pregnancy, defined as intrauterine pregnancy with confirmed heartbeat by 6-8 weeks of gestation.

Investigated diseases

Oligospermia - A condition where a man produces an abnormally low concentration of sperm in his semen. This condition is characterized by having fewer than 15 million sperm per milliliter of semen. It is one of the common causes of male fertility problems. Asthenozoospermia - A condition characterized by reduced sperm movement or motility. In this condition, less than 40% of sperm cells show normal movement patterns. The sperm cells exist in normal numbers but have difficulty swimming efficiently enough to reach and fertilize an egg. Note: These conditions often occur together and are common causes of mild male factor infertility. They represent different aspects of sperm quality that can affect natural conception.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2023-503850-11-00Protocol codePRO001Estimated enrolment732 patientsSponsorProkrea Bcn S.L.

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