New study checks if etrasimod passes into breast milk
NCT ID NCT07153159
First seen Jun 26, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This study is testing how much of the drug etrasimod ends up in breast milk. Eight healthy breastfeeding women will take a 2 mg pill daily for a week while staying at a clinic. They will not breastfeed their babies during the study to keep them safe. Researchers will measure drug levels in blood and milk to understand how much passes through.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Etrasimod (oral tablet, 2 mg once daily for 7 days)
- What this could lead to
- If successful, this study will provide crucial data on how much etrasimod enters breast milk, helping doctors advise breastfeeding women about its safety.
- What could go wrong
- This is a very small, early-phase study in healthy women, not patients. It only measures drug levels, not health outcomes, so it cannot prove safety or effectiveness for any condition.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 1
The first testing in people. Mainly checks safety and dose, usually in a small group.
- Participants
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About 8 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Aug 2025
- Expected to finish
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Oct 2026
An estimate. End dates often move.
- Lead sponsor
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A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 to 55 years
- Sex
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Female participants only
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion 1. Healthy (as determined by medical evaluation including medical history, physical examination, laboratory tests, vital signs and 12-lead ECGs) lactating women who are actively breastfeeding or expressing breast milk, who are at least 12 weeks post partum and not currently pregnant (must have a negative pregnancy test), and must be 18 to 55 years of age, inclusive, at the time of signing the informed consent document (ICD). 2. Body mass index (BMI) of 16-35 kg/m2; and a total body weight \>45 kg (99 lb). 3. Participants must be willing to temporarily discontinue breastfeeding their infants for a total of 21 days, ie, from the evening of the day before Day 1 through to 14 days after the last dose (approximately 8 AM the morning of Day 21). Participants must be willing to regularly pump breasts throughout the study and express breast milk according to a schedule designed to maintain lactation until the completion of breast milk collection Exclusion 1. Evidence or history of clinically significant hematological, renal, endocrine, pulmonary (such as moderate or severe chronic pulmonary disorders like asthma or chronic obstructive pulmonary disease \[COPD\]), gastrointestinal, cardiovascular, hepatic, neurological/psychiatric, anaphylactic, ophthalmologic disorders (such as macular edema, uveitis, retinopathy), or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing). 2. Participants with history or presence of second-degree or third-degree atrioventricular (AV) block, sick sinus syndrome, or sinoatrial block. 3. Resting HR \<50 bpm at Screening or pre-randomization on Day 1. Measurement can be repeated up to 3 times to confirm the finding. Mean values will be used if repeated. 4. Recurrent symptomatic bradycardia or recurrent cardiogenic syncope 5. Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy). 6. Known immunodeficiency disorder, including positive serology for human immunodeficiency virus (HIV), or a first degree relative with a hereditary immunodeficiency, and history of organ transplant (except corneal transplant). 7. History or evidence of hepatitis B or hepatitis C viruses. Hepatitis B vaccination is allowed.89. 8. Participants with any of the acute or chronic infections or infection history
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As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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Pfizer Clinical Research Unit - Brussels
RECRUITINGBrussels, Bruxelles-capitale, Région de, B-1070, Belgium
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