CompletedPhase 1

A Study of Doravirine/Islatravir in Healthy Lactating Females (MK-8591A-061)

United States12 participantsStarted 2025-09-26

Plain-language summary

The goal of this study is to learn what happens to doravirine (DOR) and islatravir (ISL) in a healthy lactating female's body over time. Researchers want to learn if DOR and ISL are in breast milk.

Who can participate

Age range

18 Years

Sex

FEMALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Is at least 6-weeks postpartum at the time of administration of study drug, following the delivery of a healthy singleton neonate * Is willing and able to express breast milk using an electric pump prior to study drug administration and is expected to be able to express at least 4 times over a 24-hour period after study drug administration Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Has a history of clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, psychiatric, or major neurological (including stroke and chronic seizures) abnormalities or diseases * Has had mastitis within 30 days prior to administration of study drug

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Cumulative Amount of DOR Excreted in Breast Milk From 0 to 24 Hours (Ae0-24hrs)

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Body Weight Normalized Infant Theoretical Dose of DOR

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Relative Infant Theoretical Dose of DOR

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Cumulative Amount of Total ISL Excreted in Breast Milk From 0 to 24 Hours (Ae0-24hrs)

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Body Weight Normalized Infant Theoretical Dose of ISL

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Relative Infant Theoretical Dose of ISL

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Trial details

NCT IDNCT07086079

SponsorMerck Sharp & Dohme LLC

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-12-08

View on ClinicalTrials.gov More Healthy trials

Who can participate

Age range

18 Years

Sex

FEMALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Cumulative Amount of DOR Excreted in Breast Milk From 0 to 24 Hours (Ae0-24hrs)

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Body Weight Normalized Infant Theoretical Dose of DOR

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Relative Infant Theoretical Dose of DOR

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Cumulative Amount of Total ISL Excreted in Breast Milk From 0 to 24 Hours (Ae0-24hrs)

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Body Weight Normalized Infant Theoretical Dose of ISL

Timeframe: Predose and at designated timepoints up to 24 hours postdose

Relative Infant Theoretical Dose of ISL

Timeframe: Predose and at designated timepoints up to 24 hours postdose