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

Launched by MERCK SHARP & DOHME LLC · Jul 18, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how two medicines, doravirine and islatravir, behave in the bodies of healthy women who are breastfeeding. The researchers want to find out if these medicines pass into breast milk and how much is present over time. This information can help understand if these drugs are safe for breastfeeding mothers and their babies.

Women who might be eligible to join the study are those who are at least six weeks after giving birth to a healthy single baby and are currently breastfeeding. Participants should be able to use a breast pump to collect milk several times a day during the study. The study will not include women with certain health problems, such as serious illnesses affecting organs like the heart, liver, or brain, or those who have had a breast infection called mastitis recently. If you join, you can expect to express breast milk multiple times so researchers can test it after you take the study medicines. This study is currently not recruiting participants but aims to provide important information about these medicines in breastfeeding women.

Gender

FEMALE

Eligibility criteria

• 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