Efficacy, Safety, and Pharmacokinetics of Etrasimod in Pediatric Participants with Moderately to Severely Active Ulcerative Colitis: A Phase 2 Study

The primary objective is to evaluate the efficacy of etrasimod on achieving clinical remission in pediatric participants aged 2 to less than 12 years with moderately to severely active ulcerative colitis after 52 weeks of treatment. 5 The secondary objectives include:

• Assessment of efficacy regarding endoscopic improvement, symptomatic remission, corticosteroid-free remission, and clinical response through week 52.
• Evaluation of safety and tolerability up to week 52 and long-term extension.
• Analysis of pharmacokinetics in the pediatric population.
• Assessment of the taste acceptability and palatability of tablets and granules.

The study involves a total of 10 participants diagnosed with ulcerative colitis. The study population consists of pediatric patients, specifically those aged between 2 years and less than 12 years. Eligible individuals must have moderately to severely active disease, characterized by a Mayo endoscopic score between 5 and 9, including an endoscopic subscore of at least 2 and a rectal bleeding subscore of at least 1. Participants must have a diagnosis confirmed through histology and endoscopy extending proximal to the rectum for at least 4 weeks prior to screening. Inclusion requires a documented inadequate response, loss of response, or intolerance to at least one conventional therapy or biologic or Janus kinase inhibitor.

This Phase 2, open-label, single-arm study is designed to evaluate the efficacy, pharmacokinetics, and safety of etrasimod in pediatric participants aged 2 to less than 12 years with moderately to severely active ulcerative colitis. The research methodology focuses on assessing clinical remission based on the modified Mayo score after 52 weeks of treatment. The study sequence begins with a screening period to confirm diagnosis through histological and endoscopic evaluation. Following baseline, participants receive the investigational product, which is administered in tablet or granule forms. Clinical assessments and monitoring of adverse events occur throughout the treatment period, including evaluations at Week 12 and the end-of-study visit at Week 52. Secondary endpoints include endoscopic improvement, corticosteroid-free remission, and the Pediatric Ulcerative Colitis Activity Index. The expected duration of participant involvement is 52 weeks.

The experimental treatment consists of etrasimod arginine administered as Etrasimod Arginine Blue. This substance is provided in tablet form and is administered via the oral route at a dosage of 2 mg.

The study also involves PF-07915503, which contains the active substance etrasimod arginine. This product is administered as granules through an oral route.

The primary efficacy endpoint is clinical remission based on the modified Mayo score (MMS) at Week 52. Secondary efficacy assessments include clinical remission via MMS at Week 12. Additional secondary endpoints derived from MMS components are evaluated individually at Week 12 and Week 52, comprising clinical response, endoscopic improvement, and corticosteroid-free remission.

Symptomatic remission is monitored at all time points up to Week 52. The Pediatric Ulcerative Colitis Activity Index (PUCAI) is utilized to assess PUCAI clinical remission and PUCAI clinical response. Evaluation of the investigational product includes a taste acceptability/palatability questionnaire regarding etrasimod tablets and granules.