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    • General Information >>
    • Eligibility >>
    • Study Details >>
    • Contact Information >>

    A phase 2b, multicenter, double-blind, placebo-controlled study to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of obefazimod in subjects with moderately to severely active Crohn’s disease.

    Published: 04/13/2026

    General Information:

    Click Here to Learn More »
    Study Objective

    The main purpose of this study is to see if the study drug is safe and effective in treating your CD, and whether it is safe when given for an extended period of time.

    This is a Phase 2 study. This means that the study drug has already been tested in small numbers of healthy volunteers. In addition, the study drug has been tested in patients with other medical conditions, including ulcerative colitis (another inflammatory bowel disease). This study is now testing the study drug in a group of patients with CD.

    Phase of study
    Phase 2
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    Eligibility:

    Age
    Adult (18+)
    Gender
    Female
    Male
    Disease Type
    Crohn's Disease
    Severity
    Moderate
    Severe
    Eligibility Criteria

    Inclusion Criteria: 

    • Patients at least 18 to 75 years old
    • Patients diagnosed with moderately to severely active CD
    • Patients who did not respond to currently available treatments (CD therapies), responded to CD therapy at first but are no longer responding, or could not tolerate at least one of the following treatments: corticosteroids (CS), immunosuppressants (IS), biologic or biosimilar therapies, or Janus kinase (JAK)
    • Male and female of childbearing potential as well as their partners must use an effective method of contraception during the study and for at least 21 days after the last study drug intake.
    • Investigators will review the full medical history of their patients to check for potential contra-indication for the use of obefazimod and ensure their patients eligibility.

    Main exclusion criteria:

    • Women of childbearing potential (WOCBP) who is pregnant or breast-feeding at screening, or intends to become pregnant during the study; or male subject with WOCBP partner who intends to be pregnant during the study.
    • Patients must not have CD without ileal and/or colonic involvement.
    • Patients who have failed on 5-ASA therapy only are not eligible.
    • Patients must not have untreated active external or perianal fistula or abscess, symptomatic bowel stricture and/or stenosis not passable in endoscopy.
    • Patients must not have a history of colon cancer, past or current evidence of low grade or high-grade colonic dysplasia and/or adenomatous polyps that have not been completely removed.
    • Patients must not have a recent or planned bowel surgery or more than 2 missing complete segments or current stoma or ileoanal pouch.
    • Patients with inadequate hematological and biochemical laboratory parameters obtained during the screening period are not eligible.
    • Patients with active infection or chronic or recurrent infection (grade 3 or 4) or reactivation (herpes zoster) within the last 2 months prior to screening or a history of opportunistic infection while not on immunosuppressive therapy are not eligible.
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    Study Details:

    Study description/explanation of participation:

    The ENHANCE-CD program (156 weeks including a 12-week Induction period and a 40-week Maintenance period, and a 104-week Extension period) is conducted in patients with moderately to severely active CD who have inadequate response, no response, a loss of response, or an intolerance to either conventional therapies and/or advanced therapies.

    Eligible patients will be randomly allocated into one of four treatment groups (placebo, obefazimod 12,5 mg, obefazimod 25 mg, obefazimod 50 mg) and will take one capsule orally once a day. All participants who have completed the maintenance period will receive open label obefazimod 50 mg once per day until the end of Extension period.

    Description of treatment or intervention (mechanism of action):

    Obefazimod (ABX464) has the ability to selectively upregulate a single microRNA, called miR-124, which downregulates pro-inflammatory cytokines and chemokines, thereby “putting a brake” on inflammation. Obefazimod modulates the endogenous immune system to dampen the inflammation and control the symptoms.

    Patient Participation Requirements:

    Eligible patients need to go through the following examinations during the course of the study:

    • Physical examinations will be done at each visit, and vital signs will be measured.
    • Endoscopies with biopsies will be performed before receiving the study medication, at the end of the induction period, and at the end of the maintenance period.
    • Blood samples will be collected to check patient eligibility during the screening period, and from day 1 onwards to check their safety and perform exploratory assessments.
    • Collection of stools will be done at screening to check patient eligibility and during the course of the study to assess the evolution of a marker of CD activity (fecal calprotectin).
    • An electrocardiogram will be done at screening, and during the course of the study to check the rhythm and activity of their heart.
    • An eye examination (Visual acuity and Slit Lamp) will be done at screening and on weeks 12, 28, 52,108 and 156 visits (or End of Treatment visit for subjects early discontinuing the study).
    • An electronic device (e-Diary) will be used to collect abdominal pain, number of liquid or soft stools, overall well-being as well as the number of capsules taken and the intake time.
    • Questionnaires will be completed at the study center on an electronic device on weeks 1, 12, 16, 36, 52, 108 and 156. These are to record: overall quality of life, bowel movements, abdominal symptoms, physical function, level of pain, how CD affects physical ability, emotional impact, general and mental health, impairments in both paid work and unpaid work, impact on social functioning, energy levels (vitality).
    • Pregnancy tests for people who can become pregnant, including a blood pregnancy test at each visit and a urine pregnancy test to be done monthly at home.

    Possible risks and side effects:

    As of 30 November 2024, 1300 subjects have received obefazimod, according to various administration schedules, including 97 subjects for 6 months to 1 year and 241 subjects for more than one year.

    Most frequently reported adverse events were headaches, which occurred early (first 10 days of treatment) and were transient (few days), mild or moderate (grade 1 or 2) and manageable with or without over-the-counter medications.

    Other adverse events (≥ 5% - related and non-related) were gastrointestinal disorders (nausea, vomiting, diarrhea and upper abdominal pain) and musculoskeletal (back pain). Cases of temporary increase in the blood levels of an enzyme called “lipase” have been observed in obefazimod clinical studies in patients receiving either placebo or the study drug obefazimod. 

    Progress to date (previous phase successes, links to abstracts, etc.):

    In the results currently available of the Phase 2a and Phase 2b induction and maintenance trials, obefazimod has demonstrated a rapid onset of action and maintained efficacy in moderate-to-severe UC patients. The safety database of over 1,000 patients treated to date with obefazimod indicates a favorable safety and tolerability profile.

    Publication highlighting the results of obefazimod (ABX464) in the Phase 2a and Phase 2b trials:

    ABX464 (obefazimod) for moderate-to-severe, active ulcerative colitis: a phase 2b, double-blind, randomized, placebo-controlled induction trial and 48 week, open-label extension, Severine Vermeire et al., Lancet Gastroenterol Hepatol, Volume 7, Issue 11, Sept. 2022, P. 1024-1035

    Induction and long-term follow-up with ABX464 for moderate-to-severe ulcerative colitis: Results of phase 2a trial, Severine Vermeire et al., Gastroenterology, Volume 160, Issue 7, June 2021, P. 2595-2598.E3

    Publications on the mechanism of action of obefazimod (ABX464):

    ABX464 (obefazimod) up-regulates miR-124 to reduce pro-inflammatory markers in inflammatory bowel diseases, Cécile Apolit et al., Clinical and Translational Gastroenterology, published online Jan. 2023

    Specific and selective induction of miR-124 in immune cells by the quinoline ABX464: a transformative therapy for inflammatory diseases, Cécile Apolit et al., Clinical and Translational Gastroenterology, published online Jan. 2023

    Both anti-inflammatory and antiviral properties of novel drug candidate ABX464 are mediated by modulation of RNA splicing, Audrey Vautrin et al., Nature Scientific Reports, Volume 9, Article number: 792, January 2019

    Press releases issued on clinical trial results with obefazimod (ABX464) in ulcerative colitis an on publications on its mechanism of action:

    Abivax Announces Positive Phase 3 Results from Both ABTECT 8-Week Induction Trials Investigating Obefazimod, its First-in-Class Oral miR-124 Enhancer, in Moderate to Severely Active Ulcerative Colitis | Abivax, (July 2025)

    Abivax reports excellent one-year efficacy and safety data of obefazimod (ABX464) phase 2b maintenance trial in ulcerative colitis, (April 2022)

    Obefazimod (ABX464) shows excellent long-term efficacy data in Abivax’s phase 2b maintenance trial in ulcerative colitis, (Oct. 2021)

    Abivax reports excellent efficacy and safety of obefazimod (ABX464) in phase 2b clinical trial in ulcerative colitis and plans to proceed to phase 3, (May 2021)

    Press releases issued on publications on the mechanism of action of obefazimod (ABX464):

    Abivax publishes novel data with respect to obefazimod’s (ABX464) anti-inflammatory mechanism of action, (Jan. 2023)

    Abivax phase 2b study results of obefazimod (ABX464) in ulcerative colitis published in the Lancet Gastroenterology & Hepatology, (Sept. 2022)

    Abivax publishes review in Drug Discovery Today on mechanism of action and transformative potential of obefazimod (ABX464) as therapy for inflammatory diseases, (Jan. 2021)

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    Contact Information:

    Site Locations

    Susquehanna Research Group LLC 4387 Sturbridge Drive Harrisburg, Pennsylvania 17110
    Heather Mckay
    (717) 238-3111
    [email protected]
    Henry Ford Columbus Center Henry Ford Hospital Suite 2c Novi, Michigan 48377
    Cecilia Werner
    (248) 344-2364
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    Clinical Research Brandon LLC 604 Medical Care Brandon, Florida 33511
    Jaydeline Preito
    (813) 448-2081
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    Auzmer Research 609 MidFlorida Dr Ste 3 Lakeland, Florida 33813
    Paulina Henao
    (863) 450-2580
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    Central Texas Clinical Research 900 East 30th Street Suite 302 Austin, Texas 78705
    Alissa Powell
    (512) 480-9660
    [email protected]
    Southern Star Research Institute LLC 2833 Babcock Rd Suite 206 San Antonio, Texas 78229
    Erika Cantu
    (210) 590-7891
    [email protected]
    OSU Inflammatory Bowel Disease Center 460 West 10th Ave Room C150N Columbus, Ohio 43210
    Jody Riley
    (614) 685-3750
    [email protected]
    Baylor University Medical Center 3500 Gaston Ave Hoblitzelle Basement H0015 Dallas, Texas 75246
    Amneet Hans
    (469) 800-7180
    [email protected]
    Tyler Research Institute 1720 S Beckham Ave Suite 101 Tyler, Texas 75701
    April Mahana
    (903) 630-6211
    [email protected]
    Wellness Clinical Research LLC 181 NW 154th St Suite 290 Miami Lakes, Florida 33016
    Rachelys Perez
    (786) 483-7856
    [email protected]
    Advanced Research Institute Inc 7114 Congress Street New Port Richey, Florida 34653
    Christina Tyson
    (727) 835-3261
    [email protected]
    University of Iowa Health Care 200 Hawkins Drive 01284 PFP Iowa City, Iowa 52242
    Ethan Hoover
    (319) 356-1616
    [email protected]
    Gastro Florida 3001 Executive DR STE 130 Clearwater, Florida 33762
    Natalie Molina
    (727) 476-5746 xEXT1039
    [email protected]
    Sarkis Clinical Trials 3301 SW 34th Circle Suite 301 Ocala, Florida 34474
    Merci Corcoran
    (352) 363-5395
    [email protected]
    Dartmouth Hitchcock Medical Center 1 Medical Center Drive Investigational Drug Service Lebanon, New Hampshire 03756
    Julie Fredriksen
    (603) 653-9877
    [email protected]
    United Medical Doctors 28078 Baxter Road Suite 530 Murrieta, California 92563
    Hector Flores
    (951) 566-5229
    [email protected]
    Rapid City Medical Center LLP 2820 Mt Rushmore Rd Rapid City, South Dakota 57701
    Liz Huag
    (605) 721-8181
    [email protected]
    University of Utah Hospitals and Clinics 1950 E Circle of Hope Dr Ste N2545, Utah 84112
    Julie Will
    (801) 587-9060
    [email protected]
    Orlando Health Digestive Health Institute 1400 S Orange Ave Orlando, Florida 32806
    Adriane Shepherd
    (321) 841-2285
    [email protected]
    Peak Gastroenterology Associates 2920 N Cascade Ave Colorado Springs, Colorado 80907
    Carlos Werner
    (719) 284-9744
    [email protected]
    Texas Digestive Specialists 512 Victoria Ln Ste 2 Harlinge, Texas 78550
    Diana Chantaca
    (956) 377-4371
    [email protected]
    Lucida Clinical Trials LLC 174 Union Street New Bedford, Massachusetts 02740
    George Silva
    (508) 720-2015
    [email protected]
    UMass Memorial Medical Center Research/ONC Pharmacy 55 Lake Avenue North Room HA 201 Worcester, Massachusetts 01655
    Peter Choi
    (774) 441-7648
    [email protected]
    Frontier Clinical Research LLC 300 Spring Creek Lane Uniontown, Pennsylvania 15401
    Heather Nativio
    (724) 550-4099
    [email protected]
    Novel Research LLC 6300 West Loop South Suite 510 Bellaire, Texas 77401
    Hassan Kahn
    (832) 770-1951
    [email protected]
    UPMC Presbyterian Hospital 3459 Fifth Avenue E626 Pittsburgh, Pennsylvania 15213
    Lori Snyder
    (412) 551-0426
    [email protected]
    Gastroenterology Consultants of SW Virginia 202 Duke of Gloucester St Roanoke, Virginia 24014
    Rebecca Butterworth
    (540) 510-3330
    [email protected]
    Research Associates of South Florida LLC 5101 SW 8th Street Suite 200 Miami, Florida 33134
    Sara Schiffer
    (786) 476-8790
    [email protected]
    GCP Clinical Research LLC 110 S Mac Dill Avenue Suite 300 Tampa, Florida 33609
    Gunjan Mengle
    (813) 240-9734
    [email protected]
    IMC Gulf Coast Gastroenterology 188 Hospital Drive Suite 405 Fairhope, Alabama 36532
    Denise Watts
    (251) 990-0360
    [email protected]
    Theia Clinical Research Center 11700 N 58th St Suite C Temple Terrace, Florida 33617
    Brittney Crawford
    (813) 690-6144
    [email protected]
    Houston Methodist Hospital 6550 Fannin St SM 451 Houston, Texas 77030
    Bobby Nguyen
    (713) 441-3247
    [email protected]
    Inquest Clinical Research 1690 Baker Road Suite B Baytown, Texas 77521
    Naheed Mehkri
    (832) 606-2053
    [email protected]
    Northwestern Memorial Hospital 211 E Ontario St, floor 17th suite 1750 Chicago, Illinois 60611
    JoseJuan Vega
    (312) 926-6519
    [email protected]
    GI Alliance Arizona Digestive Health Sun City 13640 N 99th Ave Suite 600 Sun City, Arizona 85351
    Samuel Cordivin
    (623) 972-2116 xX1271
    [email protected]
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