This is a Phase 2/3 study that comprises 5 substudies designed to evaluate the efficacy, safety, and tolerability of oral etrasimod as therapy in adult participants with moderately to severely active Crohn's disease (CD) who are refractory or intolerant to at least 1 of the current therapies for CD (ie, corticosteroids, immunosuppressants, or biologics). The overall duration of this study is up to 282 weeks, inclusive of the Screening Period, Treatment Period of up to 274 weeks (Induction, Extension or Maintenance, and Long-term Extension Periods), and the 4-Week Follow-Up Period for safety assessment.



Eligible Ages
Between 18 Years and 80 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Men or women 18 to 80 years of age, - Ability to provide written informed consent or assent and to be compliant with the schedule of protocol assessments - Diagnosed with Crohn's disease (CD) ≥ 3 months - Have moderately to severely active CD at Screening - Demonstrated inadequate response (ie, primary non-response), loss of response to, or intolerance to ≥ 1 of the following therapies for the treatment of CD: 1. Oral corticosteroids (eg, prednisone or its equivalent, budesonide) 2. Immunosuppressants (eg, azathioprine [AZA], 6 mercaptopurine [6-MP], or methotrexate [MTX]) 3. Tumor necrosis factor alpha (TNFα) antagonists (eg, infliximab, adalimumab, certolizumab pegol, or biosimilars) 4. Integrin receptor antagonist (eg, vedolizumab) 5. Interleukin -12/-23 antagonist (eg, ustekinumab) - Females of childbearing potential must be nonpregnant - Females of childbearing potential and males must use contraception

Exclusion Criteria

  • History of inadequate response (ie, primary non-response) to agents from ≥ 2 classes of biologics marketed for the treatment of CD (ie, TNFα antagonists, interleukin 12/ 23 antagonist, and integrin receptor antagonist). - Have ulcerative colitis, indeterminate colitis, microscopic colitis, ischemic colitis, radiation colitis, diverticular disease associated colitis, toxic megacolon, or active infectious colitis or test positive for Clostridioides difficile toxin at Screening. - Have functional or post-operative short-bowel syndrome or any associated complications that may require surgery or interfere with efficacy assessments - Had surgical treatment for intra abdominal abscesses ≤ 8 weeks prior to randomization or surgical treatment for perianal abscesses ≤ 4 weeks prior to randomization. - Had intestinal resection ≤ 24 weeks prior to randomization or other intra abdominal surgeries ≤ 12 weeks prior to randomization. - Have an ileostomy or a colostomy. Inclusion Criteria for Substudy 3: - Participants who entered the Extended Induction Period of Substudy 1 and Substudy 2 must have completed the Extended Induction -Week 6 Visit Inclusion Criteria for Substudy 4: - Participant must have completed the Week 52 Visit of Substudy 3 or the Week 66 Visit of Substudy A

Study Design

Phase 3
Study Type
Intervention Model
Parallel Assignment
Primary Purpose
Double (Participant, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Etrasimod Dose A
  • Drug: Etrasimod
    Dose A taken by mouth, once daily.
    Other names:
    • APD334
Etrasimod Dose B
  • Drug: Etrasimod
    Dose B taken by mouth, once daily.
    Other names:
    • APD334
Placebo Comparator
  • Drug: Placebo
    Etrasimod matching placebo tablet taken by mouth, once daily.

Recruiting Locations

Memorial Hermann Hospital- TMC Investigational Drugs Services Pharmacy (Drug Storage)
Houston, Texas 77030

Memorial Hermann Hospital (Endoscopy)
Houston, Texas 77030

Memorial Hermann Hospital (PFT)
Houston, Texas 77030

Memorial Hermann Hospital
Houston, Texas 77030

The University of Texas Health Science Center at Houston
Houston, Texas 77030

UT Health East Texas Physicians (pulmonary functions only)
Tyler, Texas 75701

More Details


Study Contact

Pfizer CT.gov Call Center

Detailed Description

This study includes 5 substudies: Substudy A - Phase 2: A Phase 2, randomized, double-blind, substudy to assess the safety, tolerability, and efficacy of oral etrasimod therapy in participants with moderate to severe CD that supports the selection of an induction and maintenance dose(s) for Phase 3. Substudy 1 - Phase 2: A Phase 2b randomized, double-blind, placebo-controlled, dose-ranging induction substudy to evaluate etrasimod as induction therapy and select an induction and maintenance dose(s) for continued evaluation in Phase 3. Substudy 2 - Induction: A Phase 3 randomized, double-blind, placebo-controlled substudy to evaluate etrasimod as induction therapy. Substudy 3 - Maintenance: A Phase 3 randomized, double-blind, placebo-controlled substudy to evaluate etrasimod as maintenance therapy. Participants from Substudy 1 and Substudy 2 will be enrolled in Substudy 3. Substudy 4 - Long-Term Extension: A long-term extension substudy for participants who complete at least 52 weeks of treatment. Participants from Substudy 3 and Substudy A are planned to be enrolled in Substudy 4.


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.