Pre Term BirthPhase 1NCT06668896
Comparing the Pharmacokinetics of a Progesterone Ring Versus a Progesterone Vaginal Insert
A Phase 1 study testing Progesterone in people with Pre Term Birth, run by Daré Bioscience, Inc..
Trial summary
This study is looking for healthy female adults to use an vaginal ring with differing amounts of the hormone progesterone and go through a series of blood draws to measure how much progesterone is in the body following the use of these vaginal rings over an extended period of time. Read more about this study
- Who is it for?
- Ages 40 to 65 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Pre Term Birth
- What is being tested?
- Progesterone
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Apr 2028
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 65 years
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Individuals assigned female at birth who are post-menopausal, women 40 to 65 years of age, inclusive. Postmenopausal is defined as 6-months of spontaneous amenorrhea with serum FSH levels > 40 mIU/mL (if not taking systemic hormone therapy) or 6 weeks postsurgical bilateral oophorectomy with or without hysterectomy.
- Able and willing to correctly and independently complete all study procedures.
- Able to read, understand, and provide written informed consent after the nature of the study has been fully explained and must be willing to comply with all study requirements and procedures.
- VA vaginal pH of ≤ 5.0. Women with vaginal atrophy may rescreen at least 6 weeks after starting either systemic or topical estradiol therapy.
- Women who are taking systemic (e.g. oral, injectable, transdermal) progesterone (P4) therapy must have at least 2 weeks of wash out from the last dose prior to visit 2.
Who cannot join
- Subjects with clinically significant chronic kidney disease defined as Glomerular Filtration Rate of <60 mL/min/1.73m2
- Subjects with uninvestigated hematuria
- Subjects with known nephrolithiasis, known polycystic kidney disease (PKD), or other known renal genetic disorders
- Subjects with prior pelvic malignancies requiring radiation therapy, or whose surgery for such has led to complications such as fistulas, etc.
- Subjects with a history of any severe acute or chronic medical or psychiatric condition or laboratory abnormality that could increase the risk associated with trial participation or study treatment administration or could interfere with the interpretation of trial results and, in the judgment of the investigator, would make the patient inappropriate for entry into the trial. This includes but is not limited to the following:
- Active chronic hepatitis B or hepatitis C infection including hepatitis B surface antigen and hepatitis C antigen positive patients with or without abnormal liver enzymes
Show all 11Show fewer
- Concurrent neurodegenerative disease
- Cardiovascular: uncontrolled hypertension, unstable angina, myocardial infarction or symptomatic congestive heart failure within the past 6 months or serious uncontrolled cardiac arrhythmia or use of Class 1 antiarrhythmic
- Dementia or significantly altered mental status that would prohibit the understanding or rendering of informed consent and compliance with the requirements of the protocol
- Subjects with hypersensitivity toward any ingredients in the study treatments.
- Participation in any other investigational drug or device trial in which administration of an investigational study drug/device occurred within 30 days or placement of a non-drug eluting medical device within 15 days prior to the Screening Visit (Visit 1). This does not include re-enrollments into this study, who require at least 14 days of washout prior to re-enrollment.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: An Open-Label, Four-Treatment, Parallel Study of the Comparative Pharmacokinetics of a Progesterone Intravaginal Ring (IVR) 8 mg and 12 mg/Day Versus Progesterone Vaginal Insert 100mg
This study is looking for healthy female adults to use an vaginal ring with differing amounts of the hormone progesterone and go through a series of blood draws to measure how much progesterone is in the body following the use of these vaginal rings over an extended period of time.
- Conditions
- Pre Term Birth
- Being tested
- Progesterone
- Keywords
- normal healthy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ProgesteroneDrug
Each arm will administer different amounts of progesterone vaginally (8mg to 100mg) over a 14-15 day time period.
| Study group | Role | What they receive |
|---|---|---|
| DARE-PTB1 8mg IVR | Experimental | Intravaginal ring containing 8mg progesterone administered once for 14 days. Receives: Drug: Progesterone |
| DARE-PTB1 12mg IVR | Experimental | Intravaginal ring containing 12mg progesterone administered once for 14 days. Receives: Drug: Progesterone |
| DARE-PTB1 12mg IVR every 3 days | Experimental | Intravaginal ring containing 12mg progesterone administered every 3 days for 15 days. Receives: Drug: Progesterone |
| Endometrin 100mg | Active comparator | 100mg progesterone vaginal insert, three times daily for 14 days. Receives: Drug: Progesterone |
What is being measured
The primary outcome is the main question the study is designed to answer.
Systemic pharmacokinetics of progesterone, Concentration over 24 hours
Describe the concentration of progesterone (P4) in blood prior to, during and after 24 hours of DARE-PTB1 IVR (8mg and 12mg) over 14 days of use.
Measured: 14 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Nov 2024
- Study startSep 2026 (estimated)
- Primary completionNov 2027 (estimated)
- Study completionApr 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pre Term BirthStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Daré Bioscience, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06668896
- Sponsor's protocol ID
- DARE-PTB1-001
- Other IDs
- 1R44HD101169-01A1
- Status last verified
- May 2026
- First submitted
- 29 Oct 2024
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label, Four-Treatment, Parallel Study of the Comparative Pharmacokinetics of a Progesterone Intravaginal Ring (IVR) 8 mg and 12 mg/Day Versus Progesterone Vaginal Insert 100mg
- ClinicalTrials.gov ID
- NCT06668896
- Acronym / sponsor ID
- DARE-PTB1-001
- Conditions
- Pre Term Birth
- Keywords
- normal healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Daré Bioscience, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Study start
- Sep 2026 (estimated)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Apr 2028 (estimated)
- First posted
- 1 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is looking for healthy female adults to use an vaginal ring with differing amounts of the hormone progesterone and go through a series of blood draws to measure how much progesterone is in the body following the use of these vaginal rings over an extended period of time.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| DARE-PTB1 8mg IVR | Experimental | Drug: ProgesteroneIntravaginal ring containing 8mg progesterone administered once for 14 days. |
| DARE-PTB1 12mg IVR | Experimental | Drug: ProgesteroneIntravaginal ring containing 12mg progesterone administered once for 14 days. |
| DARE-PTB1 12mg IVR every 3 days | Experimental | Drug: ProgesteroneIntravaginal ring containing 12mg progesterone administered every 3 days for 15 days. |
| Endometrin 100mg | Active comparator | Drug: Progesterone100mg progesterone vaginal insert, three times daily for 14 days. |
Who may qualify
- Ages
- 40 to 65 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Individuals assigned female at birth who are post-menopausal, women 40 to 65 years of age, inclusive. Postmenopausal is defined as 6-months of spontaneous amenorrhea with serum FSH levels > 40 mIU/mL (if not taking systemic hormone therapy) or 6 weeks postsurgical bilateral oophorectomy with or without hysterectomy.
- Able and willing to correctly and independently complete all study procedures.
- Able to read, understand, and provide written informed consent after the nature of the study has been fully explained and must be willing to comply with all study requirements and procedures.
- VA vaginal pH of ≤ 5.0. Women with vaginal atrophy may rescreen at least 6 weeks after starting either systemic or topical estradiol therapy.
- Women who are taking systemic (e.g. oral, injectable, transdermal) progesterone (P4) therapy must have at least 2 weeks of wash out from the last dose prior to visit 2.
Key exclusion criteria (11 listed)
- Subjects with clinically significant chronic kidney disease defined as Glomerular Filtration Rate of <60 mL/min/1.73m2
- Subjects with uninvestigated hematuria
- Subjects with known nephrolithiasis, known polycystic kidney disease (PKD), or other known renal genetic disorders
- Subjects with prior pelvic malignancies requiring radiation therapy, or whose surgery for such has led to complications such as fistulas, etc.
- Subjects with a history of any severe acute or chronic medical or psychiatric condition or laboratory abnormality that could increase the risk associated with trial participation or study treatment administration or could interfere with the interpretation of trial results and, in the judgment of the investigator, would make the patient inappropriate for entry into the trial. This includes but is not limited to the following:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ProgesteroneEach arm will administer different amounts of progesterone vaginally (8mg to 100mg) over a 14-15 day time period. | Drug | DARE-PTB1 12mg IVR, DARE-PTB1 12mg IVR every 3 days, DARE-PTB1 8mg IVR, Endometrin 100mg |
Primary outcome
Systemic pharmacokinetics of progesterone, Concentration over 24 hours
Time frame: 14 days
Describe the concentration of progesterone (P4) in blood prior to, during and after 24 hours of DARE-PTB1 IVR (8mg and 12mg) over 14 days of use.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2026.
Related trials for Pre Term Birth
Not yet recruiting
nCPAP-NAVA-Backup Versus Standard nCPAP for Severe Apnea in Preterm Infants ≤28 Weeks
Apnea of Prematurity
Recruiting
Study of the Influence of Intraperitoneal Insufflation of CO2 by Laparoscopy on the Short-term Evolution of Premature Infants With Ulcerative Necrotizing Enterocolitis
Preterm Birth, Enterocolitis, Necrotizing
RecruitingObservational study
Multidimensional Dynamic Early Warning System for Neonatal Necrotizing Enterocolitis: A Multicenter Clinical Study
NEC - Necrotizing Enterocolitis
Recruiting
Optimization of Saturation Targets And Resuscitation Trial (OptiSTART)
Premature Infants, Bronchopulmonary Dysplasia
RecruitingObservational study
Growing Little PEAPODS Study
Premature Birth, Premature Infant
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Progesterone in people with Pre Term Birth, run by Daré Bioscience, Inc..
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Andrea Thurman, MD (210-380-5241, athurman@darebioscience.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Systemic pharmacokinetics of progesterone, Concentration over 24 hours (time frame: 14 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.