Efficacy and Safety Study of ABX464 as Maintenance Therapy in Patients With Moderate to Severe Ulcerative Colitis

A Phase 2b, Open-label, Efficacy and Safety Study of ABX464 as Maintenance Therapy in Patients With Moderate to Severe Ulcerative Colitis

A phase 2b study to evaluate the long-term efficacy and safety study of ABX464 50mg as maintenance therapy in patients with moderate to severe Ulcerative Colitis.

Study Overview

• Status: Completed
• Conditions: Ulcerative Colitis
• Intervention / Treatment: Drug: ABX464

Detailed Description

This study is an open-label study aiming at evaluating the long-term safety and the efficacy profile of ABX464 given once a day (o.d) at 50 mg in subjects who have been previously enrolled in the ABX464-103 clinical study (induction study) and who are willing to continue their treatment. All subjects will receive ABX464 given at 50mg o.d regardless of their previous treatment and dose received in the ABX464-103 study (i.e. ABX464 100mg, ABX464 50mg, ABX464 25mg or Placebo). The enrolment in this follow-up study will be based on the willingness of the subject to carry on his/her participation. Subjects will be treated with ABX464 for an overall period of 48 weeks. Subjects will be followed up on a monthly basis.

• Study Type: Interventional
• Enrollment (Actual): 217
• Phase: Phase 2

Contacts and Locations

Study Locations

• Austria
  • Innsbruck, Austria
    • Medizinische Universitat Innsbruck
  • Klagenfurt, Austria
    • Klinikum Klagenfurt am Worthersee
  • Linz, Austria
    • Ordensklinikum Linz GmbH - Barmherzige Schwestern
  • Vienna, Austria
    • AKH - Medizinische Universitat Wien
• Belarus
  • Homyel, Belarus
    • Gomel Regional Clinical Hospital
  • Minsk, Belarus
    • Minsk city diagnostic center
  • Minsk, Belarus
    • Regional Clinical Hospital
  • Vitebsk, Belarus
    • Vitebsk Regional Clinical Hospital
  • Vitebsk, Belarus
    • Vitebsk regoinal clinical specialized center
• Belgium
  • Bruges, Belgium
    • AZ Sint-Lucas
  • Brussels, Belgium
    • C. H. U. St-Pierre
  • Leuven, Belgium, 3000
    • University Hospitals Leuven - campus Gasthuisberg
• Canada
  • Brandon, Canada
    • Brandon Medical Arts Clinic
  • Edmonton, Canada
    • South Edmonton Gastroenterology
  • London, Canada
    • LHSC - Victoria Hospital
  • Ottawa, Canada
    • The Ottawa Hospital - General Campus
  • Toronto, Canada
    • Mount Sinai Hospital
• Czechia
  • Brno, Czechia
    • Fakultni nemocnice u sv. Anny v Brne
  • Hradec Králové, Czechia
    • Hepato-Gastroenterologie HK s.r.o.
  • Olomouc, Czechia
    • MUDr. Gregar s.r.o.
  • Ostrava-Kunčice, Czechia
    • Fakultni Nemocnice Ostrava
  • Prague, Czechia
    • Nemocnice Na Bulovce
  • Prague, Czechia
    • Thomayerova nemocnice
  • Slaný, Czechia
    • Nemocnice Slany
• France
  • Amiens, France
    • CHU Amiens - Hopital Sud
  • Besançon, France
    • CHU Besancon - Hôpital Jean Minjoz
  • Clermont-Ferrand, France
    • CHU Clermont Ferrand - Hôpital d'Estaing
  • Clichy, France
    • Hopital Beaujon
  • Grenoble, France
    • CHU de Grenoble - Hôpital Nord
  • La Roche-sur-Yon, France
    • Centre Hospitalier Departemental Les Oudairies
  • Lille, France
    • CHU Lille - Hôpital Claude Huriez
  • Marseille, France
    • Hopital Nord - CHU Marseille
  • Montpellier, France
    • Hopital Saint Eloi
  • Nantes, France
    • CHU Nantes - Hotel Dieu
  • Nice, France
    • CHU Nice - Hopital de l'Archet 2
  • Reims, France
    • CHU Reims - Hôpital Robert Debré
  • Rennes, France
    • CHU Rennes - Hôpital Pontchaillou
  • Rouen, France
    • CHU de Rouen - Hôpital Charles Nicolle
  • Saint-Etienne, France
    • CHU Saint Etienne - Hopital Nord
  • Strasbourg, France
    • CHU Strasbourg - Hôpital Hautepierre
  • Toulouse, France
    • Hopital Rangueil
  • Vandœuvre-lès-Nancy, France
    • Hôpital de Brabois Adultes
• Germany
  • Berlin, Germany
    • Charite Universitaetsmedizin Berlin - Campus Benjamin Franklin
  • Düsseldorf, Germany
    • Florence-Nightingale-Krankenhaus-Diakonie Kaiserswerth
  • Frankfurt, Germany
    • Klinikum Der Johann Wolfgang Goethe-Universitaet
  • Halle, Germany
    • Studiengesellschaft BSF Unternehmergesellschaft haftungsbeschraenkt
  • Halle, Germany
    • Universitaetsklinikum Halle (Saale)
  • Hanover, Germany
    • Medizinische Hochschule Hannover
  • Neuss, Germany
    • Johanna-Etienne-Krankenhaus
  • Nordhausen, Germany
    • Tumorzentrum Nordthueringen MVZ GmbH
  • Riesa, Germany
    • Dr. Tasso Bieler
  • Ulm, Germany
    • Universitaetsklinikum Ulm
• Hungary
  • Balatonfüred, Hungary
    • DRC Gyogyszervizsgalo Kozpont Kft.
  • Budapest, Hungary
    • Semmelweis Egyetem
  • Budapest, Hungary
    • Obudai Egeszsegugyi Centrum Kft.
  • Budapest, Hungary
    • Pannónia Magánorvosi Centrum
  • Debrecen, Hungary
    • Debreceni Egyetem
  • Debrecen, Hungary
    • Vasutegeszsegugyi Kft. - Debreceni Egeszsegugyi Kozpont
  • Győr, Hungary
    • Petz Aladar Megyei Oktato Korhaz
• Italy
  • Bologna, Italy
    • Azienda Ospedaliera Universitaria Policlinico Sant'Orsola Malpighi
  • Brescia, Italy
    • Fondazione Poliambulanza Istituto Ospedaliero
  • Catanzaro, Italy
    • Azienda Ospedaliero Universitaria Mater Domini
  • Milan, Italy
    • I.R.C.C.S Policlinico San Donato
  • Negrar, Italy
    • Ospedale Sacro Cuore Don Calabria
  • Padova, Italy
    • Azienda Ospedaliera di Padova
  • Palermo, Italy
    • Azienda Ospedaliero Universitaria Policlinico Paolo Giaccone
  • Pisa, Italy
    • Azienda Ospedaliero Universitaria Pisana (Presidio di Cisanello)
  • Roma, Italy
    • Fondazione Policlinico Universitario Agostino Gemelli IRCCS
  • Rozzano, Italy
    • Istituto Clinico Humanitas
• Poland
  • Bydgoszcz, Poland
    • Szpital Uniwersytecki nr 2 im.dr J. Biziela
  • Gdansk, Poland
    • Uniwersyteckie Centrum Kliniczne
  • Krakow, Poland
    • Centrum Medyczne Plejady
  • Lodz, Poland
    • SANTA FAMILIA Centrum Badan, Profilaktyki i Leczenia
  • Lublin, Poland
    • Wojskowy Szpital Kliniczny w Lublinie
  • Piotrkow Trybunalski, Poland
    • Trialmed CRS
  • Poznan, Poland
    • Centrum Medyczne Grunwald
  • Puławy, Poland
    • KO-MED Centra Kliniczne Pulawy
  • Rzeszów, Poland
    • Gabinet Lekarski Bartosz Korczowski
  • Warsaw, Poland
    • Centrum Zdrowia MDM
  • Warsaw, Poland
    • NZOZ Vivamed
  • Wierzchosławice, Poland
    • Centrum Zdrowia Tuchow Sp. z o.o.
  • Wroclaw, Poland
    • LexMedica
  • Wroclaw, Poland
    • Centrum Medyczne Oporow
  • Wroclaw, Poland
    • Centrum Badan Klinicznych Piotr Napora Lekarze Spolka Partnerska
• Serbia
  • Belgrade, Serbia
    • Clinical Center " Dr Dragisa Misovic Dedinje"
  • Belgrade, Serbia
    • Clinical Center Bezanijska kosa
  • Užice, Serbia
    • General Hospital Uzice
• Slovakia
  • Bardejov, Slovakia
    • Alian s.r.o.
  • Nové Zámky, Slovakia
    • Gastromedic, s.r.o.
  • Prešov, Slovakia
    • Gastro I, s.r.o.
  • Vranov nad Topľou, Slovakia
    • Endomed, s.r.o.
  • Šahy, Slovakia
    • Accout Center s.r.o.
• Slovenia
  • Celje, Slovenia
    • General Hospital Celje
  • Maribor, Slovenia
    • University Medical Centre Maribor
  • Murska Sobota, Slovenia
    • General Hospital Murska Sobota
• Spain
  • Barcelona, Spain
    • Centro Médico Teknon
  • Córdoba, Spain
    • Hospital Universitario Reina Sofia
  • Las Palmas de Gran Canaria, Spain
    • Hospital Universitario de Gran Canaria Dr. Negrin
  • Málaga, Spain
    • Hospital Quironsalud Malaga
• Ukraine
  • Cherkasy, Ukraine
    • CNE Cherkasy Regional Hospital of Cherkasy Regional Council
  • Dnipro, Ukraine
    • I.I.Mechnykov Dnipropetrovsk Regional Clinical Hospital
  • Ivano-Frankivsk, Ukraine
    • Central City Clinical Hospital Dept of Theraphy No. 2 SHEI Ivano-Frankivsk NMU
  • Kharkiv, Ukraine
    • CHI Kharkiv City Clinical Hospital #13
  • Kharkiv, Ukraine
    • CNE Prof. O.O. Shalimov Kharkiv City Clinical Hospital #2 of KCC
  • Kharkiv, Ukraine
    • Communal Non-commercial Enterprise of Kharkiv Regional Council Regional Clinical Hospital
  • Kherson, Ukraine
    • CI Kherson CCH
  • Khmelnytskyi, Ukraine
    • Khmelnytska Regional Hospital
  • Kyiv, Ukraine
    • Communal Institution of Kyiv Regional Council Kyiv Regional Clinical Hospital
  • Lviv, Ukraine
    • Lviv Regional Clinical Hospital D.Halytskyi Lviv NMU
  • Ternopil, Ukraine
    • Ternopil University Hospital
  • Uzhhorod, Ukraine
    • A. Novak Transcarpathian Regional Clinical Hospital
  • Vinnytsia, Ukraine
    • CCH #1 Vinnytsia M.I. Pyrogov NMU Ch of Propaedeutics of IM
  • Vinnytsia, Ukraine
    • M.I. Pyrogov VRCH Dept of Gastroenterology M.I. Pyrogov VNMU
  • Vinnytsia, Ukraine
    • MCIC MC LLC Health Clinic
  • Zaporizhzhia, Ukraine
    • CI City Clinical Hospital #6 Dept of Gastroenterology
  • Zaporizhzhia, Ukraine
    • CNCE "City Hospital 9" Zaporizhzhia CC
• United Kingdom
  • Bury, United Kingdom
    • Fairfield General Hospital
  • London, United Kingdom
    • Guy's Hospital
  • London, United Kingdom
    • University College London Hospitals
  • Nottingham, United Kingdom
    • Nottingham University Hospitals Queen's Medical Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 71 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients must have completed the 16-week induction treatment period (ABX464-103);
• Patients are able and willing to comply with study visits and procedures as per protocol;
• Patients should understand, sign and date the written voluntary informed consent form prior to any protocol-specific procedures are performed;
• Patients should be affiliated to a social security regimen (for French sites only);
• Females and males receiving the study treatment (potentially in combination with immunosuppressant) and their partners must agree to use a highly effective contraceptive method during the study and for 6 months (180 days) after end of study or early termination. Contraception should be in place at least 2 weeks prior to screening. Women must be surgically sterile (bilateral oophorectomy, bilateral salpingectomy, or hysterectomy) or in the postmenopausal state (no menses for 12 months without an alternative medical cause) or if of childbearing potential must use a highly effective contraceptive method. Women of childbearing potential (WOCBP) will enter the study after confirmed menstrual period and a negative pregnancy test. Highly effective methods of contraception include true abstinence, intrauterine device (IUD) or hormonal contraception aiming at inhibition of ovulation, intrauterine hormone releasing system, bilateral tubal ligation, vasectomized partner. True abstinence is defined when this is in line with the preferred and usual lifestyle of the patient. In each case of delayed menstrual period (over one month between menstruations) confirmation of absence of pregnancy is required. This recommendation also applies to WOCBP with infrequent or irregular menstrual cycle. Female and male patients must not be planning pregnancy during the trial and for 6 months post completion of their participation in the trial. In addition, male patients should use condom during the trial and for 6 months (180 days) post completion of their participation in the study. Male patients must not donate sperm as long as contraception is required.

Criteria that should be met by patients at week 48 to be eligible for 48 additional weeks of study treatment.

• Patients should be in clinical response. Clinical response is defined as: a reduction in Modified Mayo Score ≥ 2 points and ≥ 30 % from baseline (induction) with an accompanying decrease in rectal bleeding sub-score ≥ 1 point or absolute rectal bleeding sub-score ≤ 1 point.
• Patients able and willing to continue the study treatment and who are compliant with study visits and procedures and who signed the update of the written voluntary informed consent.

Exclusion Criteria:

• Patients who had major protocol deviation(s) in the induction study;
• Patients who permanently discontinued study the treatment in induction study (ABX464-103) because of an adverse event (AE) regardless of relatedness to investigational product;
• Patients who have developed any major illness/condition or evidence of an unstable clinical condition (except UC) that, in the investigator's judgment, will substantially increase the risk to the participant if he or she participates in the study;
• Patients with any other severe acute or chronic medical or psychiatric condition or laboratory or electrocardiogram (ECG) abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the patient inappropriate for entry into this study;
• Patients who are participating or plan to participate in other investigational studies (other than induction study) during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ABX464 50mg; All subjects will receive ABX464 administered at 50 mg o.d for an overall period of 96 weeks.	Drug: ABX464; ABX464 All subjects will receive ABX464 administered at 50 mg o.d for an overall period of 96 weeks.; Other Names: Obefazimod

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Patients With Clinical Remission at Week 48 Compared to Baseline of Induction Study (ABX464-103)	Clinical remission (based on the Mayo scoring system) is defined as: a rectal bleeding sub-score = 0, and an endoscopy sub-score ≤1 (excluding friability), and at least 1-point decrease in stool frequency sub-score from baseline to achieve a stool frequency sub-score ≤1	week 48

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Patients With Clinical Response at Weeks 48 and 96 Compared to Baseline of Induction Study	Proportion of patients with clinical response at week 48 Clinical response is defined as: a reduction in Mayo Score ≥ 3 points and ≥ 30 % from baseline with an accompanying decrease in rectal bleeding sub-score ≥ 1 point or absolute rectal bleeding sub-score ≤ 1 point.	Weeks 48 and 96
Endoscopic Improvement at Weeks 48 and 96	Proportion of patients with endoscopic improvement at week 48 among all patients. Proportion of patients with endoscopic improvement at week 96 among all patients. Endoscopic improvement is defined as a Mayo endoscopic sub score of ≤1 (excluding friability).	week 48 and week 96
Endoscopic Remission at Weeks 48 and 96	Proportion of patients with endoscopic remission at week 48 among all patients. Proportion of patients with endoscopic remission at week 96 among all patients. Endoscopic remission is defined as a Mayo endoscopic sub score of 0.	week 48 and week 96
miRNA-124 Expression	Change relative to baseline in miRNA-124 expression in rectal/sigmoidal biopsies at week 48 and in total blood at week 24 and week 48.	baseline, week 24 and week 48
Incidence and Description of Adverse Events	Number and rate of all adverse events, causally-related adverse events, all serious adverse events and causally-related serious adverse events classified by severity. Incidence of treatment-emergent serious adverse events, hospitalizations, total inpatient days. Incidence of adverse events leading to investigational product discontinuation. Number of clinically significant laboratory abnormalities.	From baseline to week 96
Sustained Endoscopic Changes at Week 48 and Week 96	Proportion of patients with sustained endoscopic changes at week 48 and 96. Sustained endoscopic changes is defined as the number of patients with endoscopic changes at week 48 among patients who had endoscopic changes during the Induction study (at week 8 or week 16 of study ABX464-103).	weeks 48 and 96
Change in Modified Mayo Score and in Partial Modified Mayo Score	Change in Modified Mayo Score (MMS) at weeks 48 and 96 and in partial Modified Mayo Score (pMMS) MMS is a composite score of UC disease activity calculated as the sum of the following 3 subscores: Stool frequency, scored from 0 (normal number of stools) to 3 (5 or more stools more than normal).; Rectal bleeding, scored from 0 (no blood seen) to 3 (blood alone passed).; Endoscopic evaluation, scored from 0 (normal or inactive disease) to 3 (severe disease, spontaneous bleeding, ulceration). The overall MMS ranges from 0 to 9 where higher scores represent more severe disease. pMMS is a composite score of UC disease activity calculed as the sum of the following 2 subscores: Stool frequency, scored from 0 (normal number of stools) to 3 (5 or more stools more than normal).; Rectal bleeding, scored from 0 (no blood seen) to 3 (blood alone passed). The overall pMMS ranges from 0 to 6 where higher scores represent more severe disease.	From baseline to week 96
Stool Frequency Subscore	Participants recorded stool frequency using a paper subject diary on a daily basis. The stool frequency subscore ranges from 0 to 3 according to the following scale: Score 0: Normal number of stools Score 1: 1 to 2 stools per day more than normal Score 2: 3 to 4 stools per day more than normal Score 3: 5 or more stools per day more than normal	From baseline to week 96
Rectal Bleeding Score	Participants recorded rectal bleeding in a paper subject diary on a daily basis. Rectal bleeding score is taken as the worst subscore of the three most recent scores within 7 days prior to the visit. The rectal bleeding subscore ranges from 0 to 3 according to the following scale: Score 0: No blood seen Score 1: Streaks of blood with stool less than half the time Score 2: Obvious blood with stool most of the time Score 3: Blood alone passed A lower score represents an improvement in rectal bleeding.	From baseline to week 96
C-Reactive Protein	Change to baseline in C-Reactive Protein levels	baseline, week 24, week 48

Collaborators and Investigators

• Sponsor: Abivax S.A.
• Investigators: Principal Investigator: Severine VERMEIRE, MD, Universitaire Ziekenhuizen KU Leuven

Publications and helpful links

General Publications

• Vermeire S, Sands BE, Tilg H, Tulassay Z, Kempinski R, Danese S, Bunganic I, Nitcheu J, Santo J, Scherrer D, Biguenet S, Ehrlich HJ, Steens JM, Gineste P, Sandborn WJ. ABX464 (obefazimod) for moderate-to-severe, active ulcerative colitis: a phase 2b, double-blind, randomised, placebo-controlled induction trial and 48 week, open-label extension. Lancet Gastroenterol Hepatol. 2022 Nov;7(11):1024-1035. doi: 10.1016/S2468-1253(22)00233-3. Epub 2022 Sep 6.
• Vermeire S, Nitcheu J, Gineste P, Flatres A, Santo J, Scherrer D, Peyrin-Biroulet L, Dulai PS, Danese S, Dubinsky M, Tilg H, Siegmund B, Hisamatsu T, Shan K, Rabbat CJ, Sands BE. Obefazimod in patients with moderate-to-severely active ulcerative colitis: efficacy and safety analysis from the 96-week open-label maintenance phase 2b study. J Crohns Colitis. 2025 May 8;19(5):jjaf074. doi: 10.1093/ecco-jcc/jjaf074.

Study record dates

Study Major Dates

• Study Start (Actual): January 13, 2020
• Primary Completion (Actual): February 23, 2023
• Study Completion (Actual): February 23, 2023

Study Registration Dates

• First Submitted: July 5, 2019
• First Submitted That Met QC Criteria: July 16, 2019
• First Posted (Actual): July 17, 2019

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 22, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: moderate to severe ulcerative colitis
• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Colitis; Colitis, Ulcerative; ABX464
• Other Study ID Numbers: ABX464-104

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No