Introduction

Fistulizing perianal Crohn’s disease (CD) remains a significant therapeutic challenge, with limited randomized controlled trials to date, restricted so far to infliximab and, more recently, filgotinib. The USTAP (NCT04496063) trial aimed to evaluate the efficacy and safety of UST in patients with actively draining perianal fistulas through a multicenter randomized controlled design.

Aims & Methods

This double-blind, placebo-controlled, multicenter trial enrolled adult patients with active draining fistulizing perianal CD. Between April 2020 and June 2024, eligible patients with persistent fistula drainage were randomized 1:1, after seton placement when necessary, to receive either UST (6 mg/kg IV at baseline followed by 90 mg SC at week 8, then every 8 weeks) or placebo. Steroids were allowed at baseline with a standardized steroid taper. Seton removal was planned at week 6. The primary endpoint was combined clinical remission (absence of drainage from all external fistula openings) and radiological remission (defined as the absence of abscesses >2 cm confirmed by blinded central pelvic MRI) at week 12. Secondary endpoints included clinical remission, radiological remission, changes in disease activity (CDAI, PDAI), IBD-DI, and safety. Endpoints were independently reviewed by a blinded adjudication committee. Randomization was stratified by prior anti-TNF exposure and study center. The intended sample size was 73 patients per group to detect a 20% difference in remission rates (power 80%, alpha 5%). Due to slow recruitment, the study was discontinued in June 2024 after randomizing 32 patients, without unblinding the study data. Patients were subsequently followed until week 48.

Results

Thirty-three patients consented to participate with 32 patients (women: 41%; median age: 42) ultimately randomized (UST: 16; placebo: 16) across 10 French centers. Seventy percent had prior anti-TNF exposure (50% in UST arm, 50% in placebo arm), and 23% had previously failed two or more anti-TNF therapies. At baseline, 84% had one draining fistula, 16% had two, and 25% had associated abscesses. At week 12, combined remission was achieved in 62% in the UST group versus 25% in the placebo group (Table). Clinical remission was observed in 69% in the UST group vs. 31% in the placebo group, while radiological remission rates were 87.5% in the UST group and 75% in the placebo group. In the UST arm, mean change in CDAI, PDAI and IBD-DI from baseline to week 12 was -56.3, -2.2 and -4.9, (vs. -9.8, -1.6 and +4.9, in the placebo arm, respectively). Adverse events (AE) and serious adverse events (SAE) were similar in both treatment groups: 23 AE (62%) occurred in the placebo group, and 14 AE (38%) in the UST group. Six SAEs were reported overall, including two gastrointestinal events, one renal disorder, and one anal abscess. Two patients in the placebo group discontinued study by week 6 due to SAEs (an anal abscess and a peri-ileal abscess).

Conclusion

In this trial, where the majority of patients had prior anti-TNF exposure, the observed short-term clinical benefit of UST supports its use in fistulizing perianal CD.

Disclosure

This work was supported by a grant from Johnson & Johnson
Pauline Wils : Johnson & johnson, Takeda, Amgen, Abbvie, Celltrion, Ferring
S Nancey: Abbvie, Johnson and Johnson, Fresenius Kabi, Biogen, Takeda, Medac, Celltrion, MSD, Pfizer, Sandoz, Lilly,Ferring, Amgen
E. Messmer: No conflict of interest for this study
A Bourreille: Johnson and Johnson
A Buisson: Consulting fees from: Abbvie, Amgen, Arena, Biocon, Biogen, Celltrion Healthcare, CTMA, Ferring, Galapagos/AlfaSigma, GutyCare/Resilience Janssen, Lilly, MSD, Nexbiome, Pileje, Pfizer, Roche, Sandoz, Takeda et Tillotts. Lecture fees from: Abbvie, Amgen, Biogen, Celltrion Healthcare Galapagos/AlfaSigma, Ferring, Janssen, Lilly, Mayoli-Spindler, MSD, Nordic Pharma, Norgine, Pfizer, Roche, Takeda, Tillotts and Vifor Pharma. Research grants/fundings from: Abbvie, Celltrion Healthcare, Janssen, Lessaffre, Lilly, Pfizer, Sandoz and Takeda
L Caillo: No conflict of interest for this study
L Vuitton: abbvie amgen J&J Pfizer Takeda Lilly MSD Mayoli Ferring Dr Falk Alpha Sigma
R Altwegg: Abbvie, Johnson ans Johnson, Takeda, Pfizer, Lilly, Alphasigma, Celltrion, Amgen, Biogen, Sandoz, Ferring
X Hébuterne reports clinical research funding from Abbvie, Abivax, Amgen, Celltrion, Lilly, Fresenius-Kabi, J&J, InDex Pharmaceuticals, Pfizer, Prometheus, MSD, Roche, Takeda, serving on advisory boards for Abbvie, Biogen, Celltrion, Lilly, J&J, and participating in lectures and educational activities for Abbvie, Amgen, Celltrion, Lilly, Fresenius-Kabi, Galapagos, J&J, MSD, Nestlé Health Sciences, Nutricia, Pfizer, Tillots, Takeda.
O Ernst: No conflict of interest for this study
P Meunier: No conflict of interest for this study
V Laurent: No conflict of interest for this study
D Laharie: received board and lecture fees from: Abbvie, Alfasigma, Amgen, Biogen, Celltrion, Ferring, Fresenius-Kabi, Janssen, Lilly, MSD, Pfizer, Roche, Sandoz, Takeda
E Vicaut: No conflict of interest for this study
L Peyrin-Biroulet: Consulting : Abbvie, Abivax, Adacyte, Alimentiv, Amgen, Applied Molecular Transport, Arena, Banook, Biogen, BMS, Celltrion, Connect Biopharm, Cytoki Pharma, Enthera, Ferring, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GSK, IAC Image Analysis, Index Pharmaceuticals, Inotrem, Janssen, Lilly, Medac, Mopac, Morphic, MSD, Nordic Pharma, Novartis, Oncodesign Precision Medicine, ONO Pharma, OSE Immunotherapeuthics, Pandion Therapeuthics, Par' Immune, Pfizer, Prometheus, Protagonist, Roche, Samsung, Sandoz, Sanofi, Satisfay, Takeda, Telavant, Theravance, Thermo Fischer, Tigenix, Tillots, Viatris, Vectivbio, Ventyx, Ysopia ; lecture : Abbvie, Amgen, Arena, Biogen, Celltrion, Ferring, Galapagos, Genentech, Gilead, Janssen, Lilly, Medac, MSD, Nordic Pharma, Pfizer, Sandoz, Takeda, Tillots, Viatris

Introduction

The phase 2b GALAXI 1 and phase 3 GALAXI 2&3 studies evaluated guselkumab (GUS), a dual-acting IL-23p19 subunit inhibitor, in participants (pts) with moderately to severely active CD.¹ Pts treated with ustekinumab (UST) who met inadequate response criteria during the long-term extension (LTE) could cross over to GUS 200 mg SC q4w. Here, we present efficacy and safety results in pts who received GUS after experiencing an inadequate response to UST in the pooled GALAXI LTE.

Aims & Methods

Individuals with prior inadequate response or intolerance to UST were excluded from GALAXI; however, during the LTE, pts treated with UST 90 mg SC q8w who met inadequate treatment response criteria (not in clinical response [≥100-point reduction in CDAI score from baseline or CDAI<150] and CDAI ≥220) between Wks 52-80 of LTE were eligible for a treatment switch to GUS 200 mg SC q4w, without IV induction. Clinical response and clinical remission (CDAI<150) were both assessed 16 weeks after treatment switch. Endoscopic response (≥50% improvement from baseline SES-CD or SES-CD≤2) and endoscopic remission (SES-CD≤4 and ≥2-point reduction from baseline and no subscore >1 in any individual component) were assessed at Wk 96. Safety was assessed through Wk 96.

Results

In total, 80 pts treated with UST underwent treatment switch to GUS 200 mg SC q4w maintenance therapy due to meeting inadequate treatment response criteria between Wks 52-80 of the LTE. Of these 80 pts, 75 were included in the efficacy analyses (baseline mean age, 35.2yrs; male, 64.0%; mean CD disease duration, 8.21yrs; mean CDAI, 291.5; mean SES-CD, 12.8; history of inadequate response/intolerance to biologics [BIO-IR], 60.0%).
The proportions of pts achieving clinical response and clinical remission 16 weeks after treatment switch from UST to GUS 200 mg SC q4w were 61.3% and 52.0%, respectively. These results were comparable to the proportions of pts treated with GUS 200 mg IV q4w induction in the BIO-IR subgroup of the total LTE population who achieved clinical response and clinical remission at Wk 12 (61.7% and 46.7%, respectively).
The proportions of pts achieving endoscopic response and endoscopic remission at Wk 96 (ie, ~1 year after treatment switch from UST to GUS 200 mg SC q4w) were 49.3% and 30.7%, respectively. These results were similar to the proportions of pts in the BIO-IR subgroup receiving GUS 200 mg SC q4w maintenance who achieved endoscopic response and endoscopic remission at Wk 48 (57.2% and 35.5%, respectively).
Safety results are summarized in the Table.

Table. Safety Summary From Treatment Switch Through Week 96

Conclusion

Among pts who experienced inadequate response to UST in the LTE, more than half achieved clinical remission 16 weeks after treatment switch to GUS 200 mg SC q4w, and approximately 50% were in endoscopic response ~1 year after treatment switch. These data suggest pts with an inadequate treatment response to UST may benefit from GUS treatment. Results should be interpreted considering that pts received GUS SC maintenance therapy directly without IV induction. Key safety event rates were consistent with the known safety profile of GUS in approved indications.

References

1) Sachen K, Hammaker D, Sarabia I, et al. Frontiers in Immunology. 2025; doi:10.3389/fimmu.2025.1532852.

Disclosure

AA reports potential conflicts of interest with AbbVie, Bristol Myers Squibb/Celgene, DiaSorin, Eli Lilly, Gilead, IBD Horizons, Janssen, Pfizer, Takeda, and TLL Pharmaceuticals
DW reports consulting fees from AbbVie, Bristol Myers Squibb, Janssen, Lilly, Pfizer, Takeda
RL reports having received advisory board fees from AbbVie, Aspen, BMS, Celgene, Celltrion, Chiesi, Ferring, Glutagen, Hospira, Janssen, Lilly, MSD, Novartis, Pfizer, Prometheus Biosciences, and Takeda; received research grants from Celltrion, Shire, Janssen, Takeda, Joanna Tiddy grant from University of Sydney, McCusker Charitable Trust, Gastroenterological Society of Australia, NHMRC, Gutsy Group, and Pfizer
RVR, WvD, and CB are employees of Johnson & Johnson and own company stock/stock options.
TH received grant support from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, JIMRO Co. Ltd., Zeria Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Nippon Kayaku Co. Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc., Mochida Pharmaceutical Co. Ltd., Boston Scientific Corporation, Kissei Pharmaceutical Co. Ltd., consulting fees from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, Janssen Pharmaceutical K.K., Pfizer Inc., Nichi-Iko Pharmaceutical Co. Ltd., Eli Lilly, Gilead Sciences, Bristol Myers Squibb, and lecture fee from Mitsubishi Tanabe Pharma Corporation, AbbVie GK, EA pharma Co. Ltd., Kyorin Pharmaceutical Co. Ltd., JIMRO Co., Janssen Pharmaceutical K.K., Mochida Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc. Kissei Pharmaceutical Co. Ltd.
JP reports consultancy fees/honorarium from AbbVie, Alimentiv, Athos, Atomwise, Boehringer Ingelheim, Celsius, Ferring, Galapagos, Genentech/Roche, GlaxoSmithKline, Janssen, Mirum, Nimbus, Pfizer, Progenity, Prometheus, Protagonist, Revolo, Sanofi, Sorriso, Surrozen, Takeda, and Wasserman, and has served on a data safety monitoring board for Alimentiv, Mirum, Sorriso, Sanofi, and Surrozen.

Introduction

Microplastic particles (MPs), defined as plastic fragments smaller than 5 mm, are pervasive pollutants that accumulate in ecosystems and the human food chain (1). Literature points at various health risks, including the induction of carcinogenesis (2). Emerging evidence from animal models (3) suggests that MPs may influence the gut microbiome, but the impact on the human gut microbiome remains poorly understood.

Aims & Methods

This study aimed to evaluate how various MP types influence gut microbial composition and metabolism using an ex vivo bioreactor model, with a focus on exploring potential carcinogenic effects arising from MP–microbiome interactions.
Stool samples from healthy donors were used to inoculate bioreactor cultures, which were maintained under anaerobic conditions for five days with daily nutrient feeding. These cultures were exposed to five common MP types—polystyrene (PS), polypropylene (PP), low-density polyethylene (LDPE), poly(methyl methacrylate) (PMMA), and polyethylene terephthalate (PET)—at concentrations mimicking both estimated human exposure (4) and higher doses to assess dose-dependence. Cell viability and total bacterial counts, as well as culture pH, were measured throughout the experiment. To further explore potential microbiome and metabolic alterations, 16S rRNA gene sequencing and targeted metabolomics were performed.

Results

MP exposure did not lead to significant changes in total or viable bacterial cell counts. However, MP-treated cultures exhibited a consistent and significant decrease in pH compared to controls, suggesting changes in microbial metabolic activity. Microbiome sequencing revealed plastic-type-dependent alterations in microbial composition, with certain bacterial taxa increasing or decreasing in abundance depending on the MP type. These shifts occurred across multiple genera within diverse families, including Lachnospiraceae, Oscillospiraceae, Enterobacteriaceae, and Ruminococcaceae, with the majority of changes occurring withing the phylum Bacillota. These compositional changes were accompanied by shifts in the metabolomic profiles, some of which correlated with the observed pH changes. Several plastic types induced changes in valeric acid levels, while individual MP types were associated with alterations in distinct metabolites such as uracil, lactic acid, and acetic acid.

Conclusion

This study demonstrates that MPs can affect gut microbial activity and metabolism without significantly altering overall bacterial abundance in the short term. The variation in microbiome response across plastic types highlights the complexity of MP-microbiome interactions. Changes in faecal pH are known to be associated with various gastrointestinal diseases (5). Interestingly, some of the MP-induced changes in microbial composition resembled patterns linked to diseases such as depression and colorectal cancer. In contrast, other changes showed patterns that differed from those typically associated with conditions like Parkinson’s disease and irritable bowel syndrome, highlighting the complexity of these associations and the dependency on the context. The bioreactor model provided a controlled environment for identifying direct MP-microbiome interactions; however, in humans, additional factors like diet, immune response, and individual microbiome variations play a role in determining long-term effects. Exposure duration may also play a critical role in shaping the extent and nature of microbiome alterations (6), underscoring the need for further research into the effects of chronic MP exposure and associated health risks.

References

(1) Mamun, A. A., Prasetya, T. A. E., Dewi, I. R., & Ahmad, M. (2023). Microplastics in human food chains: Food becoming a threat to health safety. The Science of the total environment, 858(Pt 1), 159834. https://doi.org/10.1016/j.scitotenv.2022.159834
(2) Kumar, R., Manna, C., Padha, S., Verma, A., Sharma, P., Dhar, A., Ghosh, A., & Bhattacharya, P. (2022). Micro(nano)plastics pollution and human health: How plastics can induce carcinogenesis to humans?. Chemosphere, 298, 134267. https://doi.org/10.1016/j.chemosphere.2022.134267
(3) Hirt, N., & Body-Malapel, M. (2020). Immunotoxicity and intestinal effects of nano- and microplastics: a review of the literature. Particle and fibre toxicology, 17(1), 57. https://doi.org/10.1186/s12989-020-00387-7
(4) Senathirajah, K., Attwood, S., Bhagwat, G., Carbery, M., Wilson, S., & Palanisami, T. (2021). Estimation of the mass of microplastics ingested - A pivotal first step towards human health risk assessment. Journal of hazardous materials, 404(Pt B), 124004. https://doi.org/10.1016/j.jhazmat.2020.124004
(5) Yamamura, R., Inoue, K. Y., Nishino, K., & Yamasaki, S. (2023). Intestinal and fecal pH in human health. Frontiers in Microbiomes, 2, 1192316.
(6) Yin, L., Yang, M., Teng, A., Ni, C., Wang, P., & Tang, S. (2025). Unraveling Microplastic Effects on Gut Microbiota across Various Animals Using Machine Learning. ACS nano, 19(1), 369–380. https://doi.org/10.1021/acsnano.4c07885

Introduction

Duvakitug, a human IgG1 monoclonal antibody, inhibits TL1A binding to death receptor 3 (DR3), which drives inflammation in Crohn’s disease (CD). The RELIEVE-UCCD trial (NCT05499130), a 14-week induction study, evaluated duvakitug in ulcerative colitis and CD. This was the first placebo-controlled study of an anti-TL1A in moderately to severely active CD. This subgroup analysis was performed to understand the impact of duvakitug in patients with moderate and severe endoscopic inflammation by assessing Week 14 outcomes in subgroups based on endoscopic disease severity at baseline.

Aims & Methods

Patients with CD (N=138) were randomized (1:1:1) to receive a subcutaneous (SC) loading dose (LD) of duvakitug 2250 mg followed by SC duvakitug 900 mg or duvakitug 450 mg every 2 weeks (q2w), or matching placebo LD followed by placebo q2w. Patients were required to have a simple endoscopic score for Crohn’s disease (SES-CD) ≥6 (≥4 for isolated ileal disease) for study eligibility. In this analysis, endoscopic and patient-reported clinical outcomes were assessed by baseline SES-CD scores of ≤15 (moderate) and >15 (severe).¹ Endpoints included response and remission based on endoscopic assessment (SES-CD) and clinical assessment [2-item Patient Reported Outcome assessment tool (PRO2)] at Week 14. Outcomes were analyzed using descriptive summary statistics.

Results

Among patients with severe endoscopic activity (SES-CD >15) at baseline, endoscopic response was achieved by 36% in the duvakitug 900 mg arm, and 18% in the duvakitug 450 mg arm compared to 8% in the placebo arm. In patients with moderate endoscopic activity (SES-CD ≤15) at baseline, endoscopic response was achieved by 51% in the duvakitug 900 mg arm, and 29% in the duvakitug 450 mg arm compared to 15% in the placebo arm (Table). Greater proportion of patients achieved endoscopic remission, clinical response and remission with both doses of duvakitug compared to placebo in the moderate and severe endoscopic subgroups (Table). The overall adverse event profile was similar across treatment arms by disease severity subgroups.

Table: Week 14 endoscopic and clinical response and remission in CD patients with moderate and severe endoscopic activity at baseline

Conclusion

In CD patients, duvakitug demonstrated efficacy in endoscopic and patient-reported clinical outcomes in both moderate and severe endoscopic activity subgroups in this Phase 2b study. Duvakitug was well tolerated across both subgroups. These findings support further development of duvakitug as a potential treatment option for moderately to severely active CD.

References

1. Moskovitz DN, Daperno M, Van Assche G. Defining and validating cut-offs for the Simple Endoscopic Score for Crohn's Disease. Gastroenterology 2007; 132:S1097.

Disclosure

W.R. has served as a speaker for AbbVie, Celltrion, Ferring, Janssen, Galapagos, Merck Sharp & Dohme, Roche, Pfizer, Sobi and Takeda; as a consultant for AbbVie, Amgen, AOP Orphan, Boehringer Ingelheim, Bristol Myers Squibb, Calyx, Celltrion, Eli Lilly, Galapagos, Gilead,
Index Pharma, Janssen, Medahead, Microbiotica, Pfizer, Teva and Takeda; as an advisory board member for AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celltrion, Galapagos, Janssen, Pfizer and Teva; and have received research funding from AbbVie, Janssen, Sandoz, Sanofi and Takeda.
V.J. has received consulting/advisory board fees from AbbVie, Alimentiv, AnaptyisBio, Arena Pharmaceuticals, Asahi Kasei Pharma, Asieris, Astra Zeneca, Bristol Myers Squibb, Celltrion, Eli Lilly, Endpoint Health, Enthera, Ensho, Ferring, Flagship Pioneering, Fresenius Kabi, Galapagos, GlaxoSmithKline, Genentech, Gilead, Innomar, JAMP, Janssen, Merck, Metacrine, Mylan, MRM Health, Pandion, Pendopharm, Pfizer, Protagonist, Prometheus Biosciences, Reistone Biopharma, Roche, Roivant, Sandoz, Second Genome, Sorriso, Spyre, Synedgen, Takeda, Teva, Ventyx and Vividion; and speaker’s fees from, Abbvie, Ferring, Bristol Myers Squibb, Eli Lilly, Fresenius Kabi, Janssen, Pfizer, Shire, Takeda and Tillotts.
B.S. has served as a consultant or received speaker’s fees from AbbVie, Abivax, Adiso Therapeutics, Alimentiv, Amgen, Arena Pharmaceuticals, Artizan Biosciences, Artugen Therapeutics, AstraZeneca, Bacainn Therapeutics, Biora Therapeutics, Boehringer Ingelheim, Boston Pharmaceuticals, Bristol Myers Squibb, Calibr, Celltrion Healthcare, ClostraBio, Connect Biopharm, Cytoki Pharma, Eli Lilly and Company, Entera, Evommune, Ferring, Fresenius Kabi, Galapagos, Gilead, Genentech, Glaxo SmithKline, Gossamer Bio, HMP Acquisition, Imhotex, Immunic, InDex Pharmaceuticals, Innovation Pharmaceuticals, Inotrem, Ironwood Pharmaceuticals, Janssen, Johnson & Johnson, Kaleido, Kalyope, Merck, MiroBio, Morphic Therapeutic, MRM Health, OSE Immunotherapeutics, Pfizer, Progenity, Prometheus Biosciences, Prometheus Laboratories, Protagonist Therapeutics, Q32 Bio, RedHill Biopharma, Sun Pharma Global, Surrozen, Synlogic Operating Company, Takeda, Target RWE, Theravance Biopharma R&D, TLL Pharmaceutical, USWM Enterprises, Ventyx Biosciences, Viela Bio, and has stock options from Ventyx Biosciences.
S.D. reports consultancy fees from AbbVie, Alimentiv, Allergan, Amgen, AstraZeneca, Athos Therapeutics, Biogen, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Enthera, Ferring Pharmaceuticals, Gilead, Hospira, Inotrem, Janssen, Johnson & Johnson, MSD, Mundipharma, Mylan, Pfizer, Roche, Sandoz, Sublimity Therapeutics, Takeda, TiGenix, UCB, and Vifor; and reports lecture fees from Abbvie, Amgen, Dr Falk Pharma, Ferring Pharmaceuticals, Gilead, Janssen, Mylan, Pfizer, and Takeda.
K.A., N.G., B.R-D. are employees of Teva Pharmaceutical Industries Ltd.
P.L. is an employee of Sanofi.
Duvakitug is being developed in partnership by Teva and Sanofi.

Introduction

Complex perianal fistulas represent one of the most challenging manifestations of Crohn’s disease. Combined surgical and medical therapy with biologic drugs represents today the first-line treatment option, but its efficacy does not exceed 60% in terms of healing. Recently, new therapeutic approaches, such as autologous microfragmented adipose tissue (M-Fat) injection, have shown promising results. Indeed, a recent non-profit prospective pilot study on 15 patients has demonstrated that the local injection of M-Fat is a safe and promising “rescue therapy” for patients with multiresistant complex fistulizing Crohn’s disease (PCD), with a 66.7% rate of combined remission in such difficult patients. It has to be highlighted that the M-Fat injection is minimally invasive, with less risk of sphincteric damage and can be carried out in day-surgery setting.

Aims & Methods

The primary aim of this multicentre double-blind randomized controlled trial (ATTIC) is to evaluate the efficacy of the infiltration of M-Fat in the healing of perianal complex fistulas not-responding to treatment with biologics. Consecutive patients referring to the 6 investigation Centers for surgical treatment of persistent complex fistulizing PCD refractory to biosurgical approach were assessed for eligibility. After baseline pelvic magnetic resonance imaging, those included were submitted to surgical drainage with “cone-like” fistulectomy, and then randomized to receive a 15 to 20 cc local injection, at the internal orifice level and along fistula tracts, of M-Fat obtained by a lipoaspiration and processed with an enzyme-free technology (treatment group), or a suture placement and injection of 15 cc of saline solution at the internal orifice (control group). Clinical follow-up were conducted at 2, 4, 8, 12, and 24 weeks; at 24 weeks after surgery, pelvic magnetic resonance was obtained. Success was defined as “combined remission”, combination of clinical (absence of drainage upon gentle finger compression) and radiological healing (absence of residual collections > 3 mm). Clinical remission was defined as clinical healing of all external openings not confirmed at radiological assessment.

Results

An overall 92 patients were screened, and 66 (33 per group) completed the 24-week follow-up. A statistically significant difference in favour of the treatment group in terms of combined remission emerged at the primary endpoint at 24-week follow-up (control group, 18.18%; treatment group: 57.58%; p = 0.0020). No significant differences in clinical outcome measures were encountered at any of the other follow-up points. No significant differences emerged between the groups in terms of recurrence rate, complication rate, and number of adverse events. Clinical remission was 63.64% in the treatment group compared to 51.52% in the control group with no statistically significant difference (p > 0.05).

Conclusion

This multicentre double-blind randomized controlled trial demonstrates that the intraoperative injection of M-Fat, associated with surgical complete drainage of perianal sepsis, is safe, effective, and reproducible in healing complex multirefractory perianal Crohn's disease, while improving the quality of life and significantly reducing the risk of definitive oostomy.