What this study is
The goal of this clinical trial is to evaluate FB301 during a mock frozen embryo transfer (FET) cycle in pre-menopausal women aged 18 to 45 years with a prior failed FET and a defined vaginal bacterial imbalance (dysbiosis).
The main question it aims to answer is:
- Does treatment with FB301 during a mock FET cycle change the proportion of participants who meet the predefined vaginal bacterial threshold compared with placebo?
Researchers will compare:
- FB301 given after an initial vaginal cleansing with chlorhexidine (an antiseptic solution),
- FB301 given after an initial vaginal cleansing with saline (saltwater), and
- A placebo capsule given after an initial vaginal cleansing with saline to determine whether these approaches affect vaginal bacterial composition and pregnancy outcomes.
Participants will take study treatment for 15 days during a "mock" FET cycle. In a mock cycle, participants receive the hormones needed to prepare the uterus for embryo transfer, but no embryo is transferred. After completing the mock cycle, participants may proceed with their planned frozen embryo transfer and will be followed during pregnancy until birth.
Participants will:
- Undergo a vaginal cleansing before receiving the first dose of FB301 or placebo
- Provide vaginal swab samples at up to 5 study visits
- Attend the study centre for up to 8 visits and participate in up to 4 follow-up phone calls
- Subsequently complete a mock FET cycle before proceeding with their planned frozen embryo transfer cycle
Participants who become pregnant will be followed-up until birth.
What's being tested
- FB-301
Intervention · DRUG
FB301 capsule
- Placebo
Intervention · DRUG
FB301 Placebo capsule
- Chlorhexidine (0.5%) Vaginal Cleanse
Intervention · OTHER
Vaginal cleanse with 0.5% Chlorhexidine solution prior to first IP administration
- Sham vaginal cleanse (saline)
Intervention · OTHER
Vaginal cleanse with saline solution prior to first IP administration.
Study details
- Official title
- A Randomized, Double-blind, Three Arm, Multi-center Phase 2 Study to Investigate the Molecular Efficacy and Safety of FB301/Chlorhexidine Compared With FB301/Sham and Placebo/Sham in a Mock FET Cycle in Female Participants 18-45 Years of Age With Asymptomatic Vaginal Molecular Dysbiosis Planning to Undergo a Frozen Embryo Transfer (FET) Cycle
- Sponsor
- Freya Biosciences ApS
- Conditions
- Vaginal Dysbiosis
- Enrolling
- 30 people
- Starts
- 2026-07-22
- Est. completion
- 2027-09-30
- Design
- Triple-blind, randomized, parallel groups, Phase 2
- Record
- View on ClinicalTrials.gov ↗
Who can join
Age 18 Years – 45 YearsSex FEMALEHealthy volunteers Not acceptedYou may qualify if
- Able to understand the study and sign a consent form.
- Is a woman aged 18 to 45 years.
- Still has regular menstrual periods (pre-menopausal).
- Has had at least one previous frozen embryo transfer (FET) that did not result in pregnancy within the past 3 years, and this was not due to either male infertility or blocked /damaged fallopian tubes.
- Willing to take part in mock frozen embryo transfer (FET) cycle and is considered medically suitable to subsequently have a frozen embryo transfer (FET) using one good-quality embryo (grade 3BB or higher).
- Willing to have only one embryo transferred during the study cycle.
- A vaginal swab taken at the first study visit shows a specific vaginal microbiome imbalance required for this study (vaginal molecular dysbiosis).
- An ultrasound scan shows no problems with uterus or pelvis that would prevent pregnancy or greatly reduce the chance of pregnancy.
- Recent fertility blood tests show FSH less than 12 IU/L (within the last 6 months)
- Recent fertility blood tests show AMH greater than 1 ng/mL (at the time of oocyte retrieval).
- Body mass index (BMI) is between 18 and 42 kg/m².
- From the first study treatment until the mock FET cycle, agrees to:; Avoid vaginal intercourse or use condoms (without spermicide or lubricant),; Avoid swimming or hot tubs,; Avoid using tampons, menstrual cups, sex toys, vaginal cleansers, lubricants, or other vaginal products unless approved by the study team.
- Willing to answer questions about sexual and reproductive activity during the study.
- Willing to provide vaginal swab samples at the clinic.
- Willing to receive the first study treatment in the clinic and use the study treatment at home as instructed.
- Screening blood tests are negative for hepatitis B, hepatitis C, HIV, and syphilis.
- Willing to attend all study visits and follow-up assessments and provide information about pregnancy and newborn health outcomes.
You can't join if
- History of five or more failed frozen embryo transfers (FET) in the past 5 years.
- Have a condition that weakens the immune system (such as uncontrolled diabetes, active cancer, or an organ transplant).
- Currently taking medications that suppress the immune system (such as systemic steroids, biologics, chemotherapy, or transplant medications).
- Is already pregnant before completing the mock FET cycle.
- Test positive for a sexually transmitted infection (such as chlamydia, gonorrhea, Mycoplasma genitalium, or Trichomonas vaginalis).
- Current vaginal yeast infection that requires treatment.
- Cannot safely take the hormone medications required for a frozen embryo transfer (such as estradiol or progesterone).
- Use of intravaginal progesterone gels or solutions.
- Needs regular antibiotics or are likely to require antibiotics during the study.
- Has taken oral, injectable, or vaginal antibiotics within 30 days before screening.
- History of gynecological cancer or other significant gynecological condition that would make participation unsafe.
- Has a medical condition that would make participation unsafe or difficult.
- Has an unstable medical or psychiatric condition that could make it difficult to follow study requirements.
- Has any other condition that could interfere with participation.
Sign in and we'll check these against your records.Full criteria on ClinicalTrials.gov ↗
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Study locations (4)
4 openCypress Medical Research Centre
Wichita, Kansas, United States
- Bryan S Baker, RN, MSM, CCRC · Contact312 214 3690bryan@cypressmrc.com
RecruitingBoston IVF
Waltham, Massachusetts, United States
- Kristin Rooney · Contact781-434-6470krooney@bostonivf.com
- Nina Resetkova, MD, MBA · Principal investigator
Not yet recruitingREACH Fertility
Charlotte, North Carolina, United States
- Patrick McPhillips · Contact704-343-4440Patrick.McPhillips@NorthCarolinaFertility.com
RecruitingDelta Hy Research LLC / Advanced Fertility Texas
Houston, Texas, United States
- David Leiman, MD, MBA · Contact713-894-4840dleiman@dhclinical.com
- Harold Minkowitz, MD · Contact713 480 3028hminkowitz@dhclinical.com
Recruiting
Study team
Sponsor
Freya Biosciences ApS
Study ID FRB-005
Frequently asked questions
The sponsor hasn't published answers to common questions for this trial.