A Study to Learn How the Study Medicine Called Etrasimod is Taken up Into Blood and Breastmilk of Healthy Breastfeeding Women

This study aims to figure out how much etrasimod, a medication, ends up in breast milk after taking it for several days. To do this, the researchers will work with at least 8 healthy women who are breastfeeding. These women will take a 2 mg dose of etrasimod every day for 7 days while staying at the testing site. During the study, they won't be allowed to breastfeed their babies to keep the babies safe. Instead, they need to have another plan for feeding their babies during this time. The study will look at how the medication is absorbed and how it moves through the body, checking things like the highest level in the blood and how long it takes to reach that level. The researchers will also see how much of the drug is in the breast milk compared to the blood and whether it's safe for the women to take. After the last dose, the women will stay at the site for at least another 24 hours before going home, and follow-up safety calls will be made about 14 and 28 to 35 days later. The whole process from start to finish will take about 10 weeks