PKB171 Against Placebo in Couples With Mild Male Factor Infertility
A Multicenter, Randomized, Double-blind, Placebo-controlled Trial to Assess the Efficacy and Safety of a Post-coital Intravaginal Gel of PKB171 in Couples With Mild Male Factor Infertility.
2 other identifiers
interventional
732
1 country
12
Brief Summary
The test medication Gel PKB171 is a vaginal gel that has not yet been licensed by the regulatory authorities. However, the active substance pentoxifylline has been available as tablets for decades and is used to increase peripheral blood flow in patients with circulation problems. Additionally, pentoxifylline is used to treat sperm samples in artificial insemination and test tube fertilisation to increase the mobility of sperm. A phase I clinical trial, 30 women were treated with Gel PKB171 for up to three times. Gel PKB171 was generally well tolerated and the most common side effects were local reactions like vaginal discharge and itching. A phase II clinical trial, investigate the efficacy and safety of two concentrations of PKB171 versus placebo in couples with asthenozoospermia who wish to conceive. A total of 72 couples were planned to be included in the study. Finally, 28 couples were enrolled, and 11 couples were randomised. Within this trial, two concentrations of pentoxifylline gel were compared (5 mL of gel PKB171 containing 150 mg (3%) of pentoxifiylline, and 5 mL of gel PKB171 containing and 200 mg (4%) of pentoxifylline. Both doses were tolerated well and revealed no safety concerns as assessed by AEs, local Gel PKB171 tolerability, laboratory parameters, vital signs, gynaecologic and physical examination, or transvaginal ultrasound findings. This study was prematurely discontinued due to low numbers of eligible subjects and high recruitment failure rates, despite several protocol amendments. PKB171 gel was well tolerated and revealed no safety concerns as assessed by AEDTs, local IMP tolerability, analytical parameters, vital signs, physical and gynecological examination, or transvaginal ultrasound findings. The aim of this clinical trial is to assess the safety and efficacy of the gel PKB171 compared to a placebo gel in couples with mild male factor infertility, unable to conceive in the last 6 and 24 months. Additionally, the safety and local tolerability of Gel PKB171 will be further investigated.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_2
Started Oct 2025
12 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
October 28, 2025
CompletedFirst Submitted
Initial submission to the registry
February 25, 2026
CompletedFirst Posted
Study publicly available on registry
June 25, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
October 28, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 28, 2027
June 25, 2026
June 1, 2026
2 years
February 25, 2026
June 22, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
To assess the efficacy up to three treaament cycles with Gel PKB171 compared with placebo in couples with mild male factor fertility
Heartbeat by the 6th-8th weeks of gestation by ecography
6-8 weeks
Secondary Outcomes (6)
To assess the efficacy of PKB171 gel compared to placebo on biochemical pregnancy rate
6-8 months
To assess the efficacy of PKB171 gel compared to placebo on ongoing pregnancy rate
12 months
To assess the efficacy of PKB171 gel compared to placebo on live birth rate.
9 months
To assess the pregnancy loss rate after PKB171 gel treatment compared to placebo on-viable intrauterine pregnancy up to 20 weeks
9 months
To compare the obstetrics characteristics of pregnancies achieved after PKB171 gel compared to placebo,
10 months
- +1 more secondary outcomes
Study Arms (2)
Gel PKB171 200 mg (equivalent to 4% pentoxiphylline)
EXPERIMENTALIntravaginal application of Gel PKB171 4% with a single-use applicator (syringe). The content fo the applicator (5g) was inserted will be inserted as deep as possible into the vagina, and the female will be rested for at least 45 minutes in bed
Gel PKB171 placebo
PLACEBO COMPARATORIntravaginal application of Gel PKB171 4% with a single-use applicator (syringe). The content fo the applicator (5g) was inserted will be inserted as deep as possible into the vagina, and the female will be rested for at least 45 minutes in bed
Interventions
Intravaginal application of gel PKB171 with a single-use applicator (syringe)
Intravaginal application of gel PKB171 with a single-use applicator (syringe)
Eligibility Criteria
You may qualify if:
- Written informed consent form signed before any study test or procedure.
- Unable to conceive for more than 6 months and less than 24 months, despite regular and adequate unprotected sexual intercourse.
- Willing and able to comply with the protocol.
- Female subjects with the following criteria:
- Age ≥ 18 and ≤ 38 years.
- Regular spontaneous menstrual cycles with a 25- to 35-day length (intercycle variation less than 5 days) within the last six cycles before the first visit.
- Normal uterine cavity shown on transvaginal sonography.
- Normal ovarian reserve, demonstrated by AMH ≥ 1 ng/ml at day 2-5 of the cycle.
- Antral follicle count (sum of both ovaries) ≥ 6
- Male subjects with the following criteria:
- Age ≥ 18 and ≤ 50 years.
- Spermiogram with semen volume ≥ 1mL, concentration \> 11 M/mL, \< 42% total mobility and normal forms ≥ 2%
You may not qualify if:
- Subjects eligible for this study, both women and men, must not meet any of the following criteria:
- Body mass Index (BMI) \< 18 and ≥ 32 kg/m².
- Any sexual intercourse with another partner (other than corresponding trial subject) within 12 weeks entry in the study and during it.
- Active hepatitis B, C, HIV, genital herpes, Chlamydia, Gonorrhea or Syphilis infection.
- History of malignant disease (cancer). Previous or planned chemotherapy or radiotherapy.
- History of cerebral or retinal hemorrhage, acute myocardial infarction.
- In females: Prohibited concomitant intravaginal products or procedures.
- Hypersensitivity or intolerance to pentoxifylline, xanthine derivatives or any of the excipients of the IMP.
- Employees of the investigator or trial center, with direct involvement in the proposed trial or other studies under the direction of that investigator or trial center, as well as family members of the employees or the principal investigator.
- People committed to an institution by virtue of an order issued either by the judicial or other authorities.
- Reasonable expectation that the subject will not be able to satisfactorily complete the study:
- History of current psychiatric illness that would interfere with the subject's ability to comply with protocol requirements or give informed consent.
- History of alcohol or drug abuse that would interfere with the subject's ability to comply with protocol requirements.
- Receipt of any investigational drug within three months of screening visit.
- Previous enrolment in this trial.
- +25 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (12)
Clinica Universidad de Navarra
Pamplona, Navarre, 31008, Spain
Hospital del Mar
Barcelona, 08003, Spain
Clinica Fertty
Barcelona, 08010, Spain
Clinica Sagrada Familia
Barcelona, 08022, Spain
Assir Dreta-Cap Pare Claret
Barcelona, 08037, Spain
Assir Dreta-Cap Roger de Flor
Barcelona, 08037, Spain
Hospital de la Santa Creu i Sant Pau
Barcelona, 08041, Spain
HM Gabinete Médico Velázquez
Madrid, 28001, Spain
Hospital Universitario San Rafael
Madrid, 28016, Spain
Clinica Universidad de Navarra
Madrid, 28027, Spain
Hospital Universitario L Paz
Madrid, 28046, Spain
Hospital Universitario Nuestra Señora de Valme
Seville, 41014, Spain
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- STUDY CHAIR
Cristina Trilla Solà, MD, PhD
Coordinator Investigator
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
February 25, 2026
First Posted
June 25, 2026
Study Start
October 28, 2025
Primary Completion (Estimated)
October 28, 2027
Study Completion (Estimated)
October 28, 2027
Last Updated
June 25, 2026
Record last verified: 2026-06
Data Sharing
- IPD Sharing
- Will not share