[4] The most common side effects include upper respiratory tract infection, hepatic transaminase elevation, and hypertension.

[4][5] Common adverse effects in studies were temporary bradycardia (slow heartbeat), usually at the beginning of the treatment, dyspnoea (breathing difficulties), and increased liver enzymes (without symptoms).

[13] In a 2009–2011 Phase II clinical trial including 464 multiple sclerosis patients, ponesimod treatment resulted in fewer new active brain lesions than placebo, measured during the course of 24 weeks.

[17] In October 2020, Janseen-Cilag International NV submitted an application for the modification of agreed pediatric investigation plan (PIP) to European Medicines Agency (including deferral and waiver criteria).

To evaluate pharmacodynamics and pharmacokinetics efficacy of ponesimod in pediatric patients with relapsing-remitting multiple sclerosis (RRMS); a multicenter, randomized, double blind clinical study of duration of 108 weeks treatment for age group 10 to less than 18 years, is in progress.