Disparities in Emergency Contraceptive Metabolism Dictate Efficacy

Oregon Health & Science University (OHSU)

Status and phase: Enrolling; Phase 4

Conditions: Contraceptive Usage

Treatments: Drug: Ulipristal acetate

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05674513

1R01HD105866-01A1 (U.S. NIH Grant/Contract)

OHSU IRB 24952

Details and patient eligibility

About

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.

Full 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.

Enrollment: 140 estimated patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: 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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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140 participants in 2 patient groups

Active CYP3A5 Allele

Active Comparator group

Description:

Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals with active CYP3A5 alleles

Treatment:

Drug: Ulipristal acetate

Inactive CYP3A5 Allele

Active Comparator group

Description:

Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals without active CYP3A5 alleles

Treatment:

Drug: Ulipristal acetate