Introduction
Obefazimod (Obe) is an oral, once-daily (QD), small molecule which enhances expression of microRNA-124 and has been studied in two Phase 2 induction trials and subsequent open-label maintenance studies [1-3] in patients (pts) with moderately to severely active ulcerative colitis (UC). Here we report efficacy and safety of two Phase 3, 8-week, induction trials in adult pts with UC from ABTECT-1 [NCT05507203] and ABTECT-2 [NCT05507216].
Aims & Methods
The multicenter, randomized, double-blind, placebo-controlled ABTECT trials enrolled pts with moderate-to-severe UC (defined as modified Mayo score (MMS)≥ 5, with rectal bleeding sub-score (RBS) ≥ 1 and centrally read endoscopic score >2) who had inadequate response, loss of response, or intolerance to at least one prior therapy (with no upper limit), including corticosteroids, immunosuppressants, biologics, S1P receptor modulators and/or JAK inhibitors. Pts were randomized 2:1:1 to Obe 50 mg QD (Obe-50), Obe 25 mg QD (Obe-25) or placebo (PBO) for 8 weeks. The primary endpoint was clinical remission (per MMS) and secondary endpoints included clinical response, endoscopic improvement, symptomatic remission, and histo-endoscopic mucosal improvement (HEMI).
Results
1272 pts were randomized and treated in ABTECT-1 (636) and ABTECT-2 (636). In both trials, baseline demographics and disease characteristics were similar between groups; 45.3% and 49.3% of pts had inadequate response to 1 or more advanced therapies. A significantly higher proportion of pts receiving Obe-50 (ABTECT-1:21.7%, ABTECT-2: 19.8%) versus PBO (2.5% and 6.3%) achieved clinical remission (Obe-50-PBO difference: ABTECT-1: 19.3%, p<0.0001; ABTECT-2: 13.4%, p=0.0001) and met all key secondary endpoints in both trials. A significantly higher proportion of pts receiving Obe-25 versus PBO achieved clinical remission (Obe-25-PBO difference: 21.4%, p<0.0001) and met all key secondary endpoints in ABTECT-1. In a pooled analysis, both Obe-50 and Obe-25 met all primary and secondary endpoints with nominal significance (p<0.0001) (Table). The overall rate of serious adverse events and treatment emergent adverse events (TEAEs) leading to study drug discontinuation for pts treated with Obe were similar to PBO. Proportions of pts who reported at least one TEAE in ABTECT-1 were 59.4%, 46.9%, and 53.2% for Obe-50, Obe-25, and PBO, respectively. For ABTECT2, TEAEs occurred in 61.0%, 50.9%, and 48.4% for Obe-50, Obe-25, and PBO, respectively. The most frequent TEAE was headache (Obe-50: 20.8-25.8%; Obe-25: 14.5-15.6%; PBO: 5.7). The headaches were mild, transient, short in duration and not a barrier to treat as evidenced by a low discontinuation rate of 0-1.6%. No signal was observed for serious, severe, or opportunistic infections or malignancies.
Table: 8-week induction efficacy of obefazimod in ABTECT-1 and ABTECT-2 Phase 3 studies, and pooled ABTECT-1 and ABTECT-2‡
| ABTECT-1 | ABTECT-2
| Pooled ABTECT-1 and ABTECT-2
|
Efficacy Endpoints at week 8, % (n)
| PBO N= 158
| Obe-25 N= 160
| Obe-50 N= 318
| Between group diff. Obe-25 vs PBO
| Between group diff. Obe-50 vs PBO
| PBO N= 159
| Obe-25 N= 159
| Obe-50 N= 318
| Between group diff. Obe-25 vs PBO
| Between group diff. Obe-50 vs PBO
| PBO N= 317
| Obe-25 N= 319
| Obe-50 N= 636
| Between group diff. Obe-25 vs PBO
| Between group diff. Obe-50 vs PBO
|
Clinical remission
| 2.5 (4)
| 23.8 (38)
| 21.7 (69)
| 21.4 p<0.0001
| 19.3 p<0.0001
| 6.3 (10)
| 11.3 (18)
| 19.8 (63)
| 5.1 p=0.1034¥
| 13.4 p=0.0001
| 4.4 (14)
| 17.6 (56)
| 20.8 (132)
| 13.2a p<0.0001
| 16.4a p<0.0001
|
Clinical response
| 28.5 (45)
| 65.6 (105)
| 61.0 (194)
| 37.2 p<0.0001
| 32.6 p<0.0001
| 33.3 (53)
| 53.5 (85)
| 63.2 (201)
| 20.1 p=0.0002¥
| 29.6 p<0.0001
| 30.9 (98)
| 59.6 (190)
| 62.1 (395)
| 28.6a p<0.0001
| 31.2a p<0.0001
|
Endoscopic improvement†
| 5.7 (9)
| 37.5 (60)
| 33.3 (106)
| 32.0 p<0.0001
| 27.8 p<0.0001
| 10.1 (16)
| 22.0 (35)
| 35.5 (113)
| 12.0 p=0.0029¥
| 25.4 p<0.0001
| 7.9 (25)
| 29.8 (95)
| 34.4 (219)
| 21.9a p<0.0001
| 26.6a p<0.0001
|
HEMI
| 3.2 (5)
| 23.8 (38)
| 23.0 (73)
| 20.7 p<0.0001
| 20.0 p<0.0001
| 7.5 (12)
| 13.2 (21)
| 23.9 (76)
| 5.7 p=0.0932¥
| 16.4 p<0.0001
| 5.4 (17)
| 18.5 (59)
| 23.4 (149)
| 13.2a p<0.0001
| 18.2a p<0.0001
|
Symptomatic remission*†
| 17.7 (28)
| 42.5 (68)
| 41.2 (131)
| 24.9 p<0.0001
| 23.7 p<0.0001
| 22.0 (35)
| 33.3 (53)
| 40.3 (128)
| 11.4 p=0.0227
| 18.0 p<0.0001
| 19.9 (63)
| 37.9 (121)
| 40.7 (259)
| 18.1a p<0.0001
| 21.0a p<0.0001
|
NRI is used for subjects with missing outcome at Week 8 and subjects reporting any IE prior to Week 8 % Difference is for Obe minus placebo and is based on estimated common risk difference using the Mantel-Haenszel weights adjusting for the randomization stratification factors: inadequate response to advanced therapies (yes/no), baseline oral corticosteroids usage (yes/no), and region (Japan/rest of world) [ABTECT-2 only]. p-values are two sided. a: for pooled analysis, all p-values are nominal Clinical remission: stool frequency sub-score (SFS) ≤1, rectal bleeding sub-score (RBS) = 0 and endoscopic sub-score ≤1 Clinical response: decrease from baseline in the MMS ≥ 2 points and ≥30% from baseline, plus a decrease in RBS ≥ 1 or an absolute RBS ≤ 1 Endoscopic improvement: endoscopic sub-score ≤1 Symptomatic remission: RBS=0, SFS <1 HEMI: combination of histologic improvement (Geboes histologic score ≤3.1) and endoscopic improvement (endoscopy sub-score ≤1) * Symptomatic remission was an “other secondary” endpoint, not multiplicity controlled, for the FDA protocol † Endoscopic improvement/symptomatic remission were co-primary endpoints for the EMA protocol and were met by both doses in both trials ‡ Hierarchical testing strategy was used starting with 50mg for the primary endpoint followed by the key secondary endpoints; the 25mg was subsequently tested for the primary endpoint followed by the key secondary endpoints. ¥ 25mg did not meet the primary endpoint at week 8 in ABTECT-2 in the FDA testing protocol, therefore p-values for key secondary endpoints for the 25mg arm in ABTECT-2 are nominal
|
Conclusion
In both ABTECT induction trials, primary and secondary endpoints were met; obe treatment led to statistically significant improvements in clinical, endoscopic, symptomatic and combined endoscopic-histologic endpoints at week 8. Obe was well tolerated with no new safety signals identified.
References
- Vermeire S, et al. J Crohns Colitis. 2023; 17: 1689-1697
- Vermeire S, et al. The Lancet Gastroenterology & Hepatology. 2022; 7: 1024-1035.
- Vermeire S, et al. J Crohns Colitis. 2025 ; 19 : jjaf074
Disclosure
Authors reports following potential conflicts of interest:
BES: Abbvie, Abivax, Adiso Therapeutics, Agomab, Alimentiv, Amgen, AnaptysBio, Arena Pharmaceuticals, Artugen Therapeutics, Astra Zeneca, Biolojic Design, Biora Therapeutics, Boehringer Ingelheim, Bristol Myers Squibb, Celltrion, Equillium, Enthera, Enveda Biosciences, Evommune, Ferring, Fzata, Galapagos, Genentech (Roche), Gilead Sciences, GlaxoSmithKline, Gossamer Bio, Imhotex, Index Pharmaceuticals, Innovation Pharmaceuticals, Kaleido, Kallyope, Lilly, Merck & Co., Microba, Microbiotica, Mitsubishi Tanabe, Mobius Care, Morphic Therapeutics, MRM Health, Nexus Therapeutics, Nimbus Discovery, Odyssey Therapeutics, OSE Immunotherapeutics, Janssen, Palisade Bio, Pfizer, Protagonist Therapeutics, Q32 Bio, Rasayana Therapeutics, Recludix Therapeutics, Reistone Biopharma, Sanofi, Sorriso Therapeutics, Spyre Therapeutics, Takeda, Target RWE,Teva, TLL Pharmaceutical, Tr1X, Trex Bio, Union Therapeutics, Ventyx Biosciences.
SV: AbbVie, Abivax, AbolerIS Pharma, AgomAb, Alimentiv, Arena Pharmaceuticals, AstraZeneca, Avaxia, BMS, Boehringer Ingelheim, Celgene, CVasThera, Cytoki Pharma, Dr Falk Pharma, Ferring, Galapagos, Genentech-Roche, Gilead, GSK, Hospira, Imidomics, Janssen, J&J, Lilly, Materia Prima, MiroBio, Morphic, MrMHealth, Mundipharma, MSD, Pfizer, Prodigest, Progenity, Prometheus, Robarts Clinical Trials, Second Genome, Shire, Surrozen, Takeda, Theravance, Tillots Pharma AG, Zealand Pharma.
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PSD: Abbvie, Abivax, Adiso, Alimentiv, Bristol Meyer Squibb, Celltrion, Genentech, Geneoscopy, Janssen, Pfizer, Takeda.
MD: Abbvie, Abivax, Arena Pharmaceuticals, Astra Zeneca, Boehringer Ingelheim International GmbH, Bristol-Meyer Squibb, Eli Lilly and Company, F. Hoffmann-La Roche Ltd, Genentech Inc, Gilead, Janssen Pharmaceuticals, Merck, Pfizer Inc, Prometheus Biosciences, Takeda Pharmaceuticals.
HT: Abbvie, Abivax, Dr Falk Pharma, ferring, Galapagos, Microbiotica, MSD, Pfizer, Takeda.
BS: AbbVie, Abivax, Boehringer Ingelheim, Bristol Myers Squibb, Dr. Falk Pharma, Eli Lilly, Endpoint Health, Falk, Galapagos, Gilead, Janssen, Landos, Materia Prima, PredictImmune, Pfizer, and Takeda; AlfaSigma, CED Service GmbH, MSD, Ferring, Galapagos, Tr1x bio
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XT: Celltrion, AbbVie, Johnson & Johnson, Lilly, Takeda, Alpha Sigma, Dr. Falk, Abivax, Biogen, Fresenius Kabi, MSD, Pfizer, Tillotts, and Thabor Therapeutics.
RA: AbbVie, Abivax, AstraZeneca, Bristol-Myers Squibb, Celltrion Healthcare, Galapagos, Johnson&Johnson, Lilly, MSD, Pfizer, and Takeda Pharma
US: AbbVie, Abivax, Amgen, Galapagos, Janssen, Eli Lilly, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Gilead Sciences, Pfizer, Roche,Takeda Pharmaceuticals
AA: AbbVie, Abivax, AG Pharma, Alfa Sigma, Astra Zeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Enthera, Ferring, Galapagos, Gilead, Giuliani, Janssen, Lionhealth, MSD, Nestlé, Novartis, Pfizer, Protagonist Therapeutics, Roche, Samsung Bioepis, Sanofi, Sandoz, Takeda, Teva Pharmaceuticals, Tillots Pharma
FB: AbbVie, Amgen, Eurogenerics, J&J, Arena Pharmaceuticals, Celltrion, Ferring, Galapagos, Janssen, Merck Sharp & Dohme, Pfizer Inc, Takeda, Celgene, Fresenius Kabi, Sandoz
DTR: Abbvie, Abivax SA, Altrubio, Athos Therapeutics, Inc, Bristol-Myers Squibb, Celltrion, Connect BioPharma, Eli Lilly & Co., Genentech (Roche) Inc., Iterative Health, Janssen Pharmaceuticals, Johnson & Johnson, Merck & Co., Odyssey Therapeutics, Pfizer, Sanofi, Spyre, Takeda Pharmaceuticals, Vedanta Biosciences, and Ventyx.