Disparities in Emergency Contraceptive Metabolism Dictate Efficacy

NCT05674513 — Phase 4, Recruiting, 140 participants, Oregon Health and Science University

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Registry	NCT05674513
Status	Recruiting
Phase	Phase 4
Study type	Interventional; non randomized, single group, masking: none, treatment
Enrollment	140 (Estimated)
Sponsor	Oregon Health and Science University (Other); collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Conditions	Contraceptive Usage
Interventions	Ulipristal acetate (Drug)
Dates	start 2023-01-09, primary completion 2026-12-31 (estimated), completion 2027-12-31 (estimated), first posted 2023-01-06, last updated 2026-07-09
Locations	1 site in United States

-Summary

The purpose of this study is to learn more about why some people are at greater risk for oral emergency contraceptive failure while others are not. The investigators want to learn if genetic differences impact the risk of emergency contraception failure.

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+Detailed description

Each of us can respond differently to a drug or medication based on our genetics. An emergency contraceptive, ulipristal acetate or UPA, normally works by stopping or delaying the ovary from releasing an egg (ovulation). Our bodies break down UPA in order to use it through a system call the cytochrome P450 pathway but this pathway can be faster or slower depending on our genetics. The investigators want to learn more about how our individual genetic differences in this pathway change how the ovary responds to UPA. The overall goal of this research is to improve the effectiveness of emergency contraception for all people.

+Arms and interventions

Arm	Type	Interventions	Description
Active CYP3A5 Allele	Active comparator	Drug: Ulipristal acetate	Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals with active CYP3A5 alleles
Inactive CYP3A5 Allele	Active comparator	Drug: Ulipristal acetate	Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals without active CYP3A5 alleles

Ulipristal acetate (Drug): Evaluating the pharmacodynamic and pharmacokinetic outcomes after 1 dose of Ulipristal acetate 30mg in individuals with and without active CYP3A5 alleles

+Outcome measures

Primary outcomes

Delay in follicular rupture [over 1 menstrual cycle (assessed up to approximately 30 days)]: Follicular rupture (yes/no) by ultrasound. Defined as the disappearance of or >50% reduction in size of the leading follicle
Concentration of UPA [5 days after taking study drug]: mean concentration maximum (Cmax) for UPA

+Eligibility

Sex: Female, ages: 18 Years to 40 Years, accepts healthy volunteers

Inclusion Criteria:

* Generally healthy women
* Aged 18-40
* regular menses (every 21-35 days) experiencing ovulatory cycles proven by a single progesterone level of 3 ng/mL or greater during the luteal phase of the screening cycle.

Exclusion Criteria:

* Pregnant, seeking pregnancy, or breastfeeding
* Known allergy to study medication
* Recent use of hormonal contraception
* Irregular periods (<21 days or >35 day cycles)
* Routine use of nonsteroidal anti-inflammatory drugs
* Metabolic disorders
* Smoking
* Any condition that would preclude the provision of informed consent
* Using drugs (within 2 weeks of study enrollment) known to interfere with the metabolism of UPA as well as drugs known to be CYP3A4 inducers, inhibitors, or CYP3A drug substrates

+Locations (1)

Facility	City	Country	Status
OHSU	Portland, Oregon	United States	Recruiting

+Investigators

ALISON EDELMAN, MD, Principal investigator, Oregon Health and Science University

+Funding

NIH grants: R01HD105866