Actively Recruiting
A Phase 1 Multiple-Dose, Open-Label Pharmacokinetic Study of Etrasimod in Healthy Lactating Women
Led by Pfizer · Updated on 2026-04-07
8
Participants Needed
1
Research Sites
4 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying how much etrasimod, a medication, is present in the breast milk of healthy breastfeeding women after taking the drug daily for several days. This phase 1, open-label study involves healthy lactating women aged 18 to 55 who are at least 12 weeks postpartum and not currently pregnant. The purpose is to understand how the drug is absorbed, how it moves through the body, and its levels in breast milk compared to blood, while also monitoring safety. Participants will take a 2 mg oral tablet of etrasimod once daily for 7 days while staying at the testing site. They will temporarily stop breastfeeding their babies for about 21 days, from the evening before the first dose until 14 days after the last dose. During this time, participants must use an alternative feeding plan and regularly pump and express breast milk according to a schedule to maintain lactation until breast milk collection ends. After the last dose, participants will remain at the site for at least 24 hours before going home. Throughout the study, researchers will collect blood and breast milk samples at specific times to measure drug concentration and how it changes over time. Safety will be monitored with physical exams, vital signs, ECGs, and laboratory tests. Follow-up safety calls will occur around 14 days and between 28 to 35 days after the last dose. The entire study process is expected to last about 10 weeks for each participant.
CONDITIONS
Brief Title
A Study to Learn How the Study Medicine Called Etrasimod is Taken up Into Blood and Breastmilk of Healthy Breastfeeding Women
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Healthy lactating women actively breastfeeding or expressing breast milk
- At least 12 weeks postpartum and not currently pregnant (negative pregnancy test required)
- Age between 18 and 55 years old
- Body mass index (BMI) of 16-35 kg/m2 and body weight over 45 kg (99 lb)
- Willingness to temporarily stop breastfeeding for about 21 days during the study
- Willing to regularly pump and express breast milk according to study schedule
You will not qualify if you...
- History or evidence of significant blood, kidney, endocrine, lung, digestive, heart, liver, neurological, psychiatric, eye, or allergic diseases (excluding untreated, asymptomatic seasonal allergies)
- History or presence of certain heart conduction problems such as second- or third-degree AV block, sick sinus syndrome, or sinoatrial block
- Resting heart rate below 50 beats per minute at screening or Day 1
- Recurrent symptomatic slow heart rate or fainting due to heart issues
- Conditions affecting drug absorption, like gastrectomy or cholecystectomy
- Known immune deficiency disorders including HIV positive status or organ transplant history (except corneal transplant)
- History or evidence of hepatitis B or C viruses
- Any current or past acute or chronic infections or infection history
AI-Screening
AI-Powered Screening
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Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 7 days
Participants take the study medicine called Etrasimod orally once a day for 7 days.
Visits for sample collection on Day -1, Day 1, Day 7, and Day 8
Duration - Up to 27 days after treatment
Participants are monitored for safety and study outcomes after treatment ends.
Visits through Day 35 for safety assessments
Trial Site Locations
Total: 1 location
1
Pfizer Clinical Research Unit - Brussels
Brussels, Bruxelles-capitale, Région de, Belgium, B-1070
Actively Recruiting
Research Team
P
Pfizer CT.gov Call Center
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
SINGLE_GROUP
Primary Purpose
BASIC_SCIENCE
Number of Arms
1
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