The purpose of this study is to evaluate the effect of steady-state carbamazepine (CBZ; a strong pregnane X receptor [PXR] agonist) on the pharmacokinetics (PK) of ponesimod following a gradual up-titration regimen in healthy adult participants.

Inclusion Criteria:

• Body mass index between (BMI) 18-30 kilograms per meter square (kg/m^2)
• Willing and able to adhere to the prohibitions and restrictions.
• Female participants with negative pregnancy test.
• Women of childbearing potential (WOCBP) must use 2 methods of contraception.
• Healthy on the basis of physical examination (including neurological examination and skin examination), Columbia suicide severity rating scale questionnaire (C-SSRS) questionnaire, ophthalmological examination, medical history, vital signs, and 12-lead electrocardiogram (ECG).
• Positive varicella zoster virus (VZV).

Exclusion Criteria:

• History of or current clinically significant medical illness including (but not limited to) cardiac arrhythmias or other cardiac disease, hematologic disease, coagulation disorders (including any abnormal bleeding or blood dyscrasias), lipid abnormalities, significant pulmonary disease, including bronchospastic respiratory disease, diabetes mellitus, hepatic or renal insufficiency (creatinine clearance below 60 milliliter per minute [mL/min]), thyroid disease, neurologic or psychiatric disease, confirmed or suspected macular edema, infection, or any other illness that the investigator considers should exclude the participant or that could interfere with the interpretation of the study results.
• Contraindications to the use of Carbamazepine (CBZ) as per local prescribing information
• Any immunosuppressive treatment within 6 weeks before first study drug administration.
• Lymphopenia (less than 1,000 cells per microliter).
• Received an investigational drug or used an invasive investigational medical device within 30 days before the first study drug intake or received a biological product within 3 months or 5 half-lives (whichever is longer) before the first study drug intake, or is currently enrolled in an investigational study.
• Lack of good/reasonable venous access.
• Any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (example, compromise the well-being) or that could prevent, limit, or confound the protocol-specified assessments.

The data sharing policy of the Janssen Pharmaceutical Companies of Johnson & Johnson is available at www.janssen.com/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu