Single Dose of Vyleesi in Lactating Female Subjects to Measure the Concentration of Bremelanotide in Breast Milk

A Phase 4, Open-Label Study of a Single Dose of Vyleesi® (Bremelanotide Injection) in Healthy, Premenopausal Lactating Female Subjects to Measure the Concentration of Bremelanotide in Breast Milk

The primary objectives of this clinical trial performed with Vyleesi (Bremelanotide Injection) are:

• to evaluate if Bremelanotide (BMT) is secreted in breast milk of lactating women treated with a single dose of BMT 1.75 mg SC.
• to measure the concentration and characterize the pharmacokinetics of BMT secreted in breast milk of lactating women treated with a single dose of BMT 1.75 mg SC.

This open-label, pharmacokinetic (PK) study will be performed in 10 healthy lactating female subjects between 10 days and 6 months post-partum (inclusive). The maximum duration of subject participation in the study will be approximately 29 days, consisting of 3-week Screening period, a 1 day treatment period, and up to a 7 day follow-up period.

Study Overview

• Status: Completed
• Conditions: Lactating Mother
• Intervention / Treatment: Drug: Vyleesi (Bremelanotide Injection)

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Florida
    • Doral, Florida, United States, 33178
      • First Excellence Research Group LLC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria (Main Criteria):

• Female subjects ≥18 to 55 years of age (inclusive) and premenopausal
• Lactating, between 10 days and 6 months postpartum (inclusive).
• Exclusively breastfeeds their infant prior to participation in the study
• Is willing to pump and store breastmilk for feeding her infant for a minimum of 48 hours in advance of study initiation and discontinue breastfeeding their infant for the duration of their study participation (beginning from time of dosing with BMT) and a minimum of 24 hours following the Safety Follow-Up visit (i.e., a minimum of 48 hours following dosing with BMT).
• Ensure at the time of screening that the breastfed infant can feed from a bottle during maternal participation in the study
• The subject is not pregnant, and does not intend to become pregnant before, during, or within 1 complete menstrual cycle or 2 months after administration of study drug
• Subjects of childbearing potential who are sexually active with a nonsterilized male partner must have stable, continuous use of an acceptable method of contraception throughout the duration of the study, and for at least 60 days after the dose of study drug

Exclusion Criteria (Main Criteria):

• Breastfeeding is not well established in the mother-infant pair (e.g., poor latching of the infant or low milk supply).
• Any condition that interferes with the successful collection of milk from one or both breasts including but not limited to lactation mastitis (typically presents as a tender, hot, swollen area of the breast that may or may not involve an infection), milk blister that may present as a blocked nipple pore, breast abscess, etc.
• Has used any investigational compound and/or an experimental medical device within 28 days before Screening.
• Has taken BMT within 24 hours of participation in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vyleesi; One dose of BMT 1.75 mg SC on Day 1	Drug: Vyleesi (Bremelanotide Injection); Single dose of BMT 1.75 mg SC on Day 1

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Levels of Bremelanotide (BMT) in Breast Milk Over 24h After Administration of Vyleesi	The levels/concentrations of bremelanotide (BMT) will be measured in breast milk samples collected at different timepoints up to 24h from lactating women who receive a single dose of Vyleesi (BMT 1.75 mg SC).	24 hours
Area under the curve from time 0 to end of dosing interval (AUCtau) for BMT in Breast Milk		24 hours
Maximum observed concentration (Cmax) of BMT in breast milk		24 hours
Time to reach Cmax of BMT in breast milk (Tmax)		24 hours
Terminal half-life of BMT in breast milk (t1/2)		24 hours

Secondary Outcome Measures

Outcome Measure	Time Frame
Levels of Bremelanotide (BMT) in Plasma Over 24h After Administration of Vyleesi	24 hours
Area under the curve from time 0 to end of dosing interval (AUCtau) for BMT in Plasma	24 hours
Maximum observed concentration (Cmax) of BMT in Plasma	24 hours
Time to reach Cmax of BMT in Plasma (Tmax)	24 hours
Milk:plasma ratio (M/P) of BMT Levels	24 hours

Collaborators and Investigators

• Sponsor: Cosette Pharmaceuticals, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): July 11, 2025
• Primary Completion (Actual): November 15, 2025
• Study Completion (Actual): November 15, 2025

Study Registration Dates

• First Submitted: February 19, 2025
• First Submitted That Met QC Criteria: March 5, 2025
• First Posted (Actual): March 10, 2025

Study Record Updates

• Last Update Posted (Actual): January 13, 2026
• Last Update Submitted That Met QC Criteria: January 12, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: bremelanotide
• Other Study ID Numbers: PMR 3635-3

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No