A Phase 4 interventional study of Guselkumab and Diet in Pouchitis, sponsored by Universitaire Ziekenhuizen KU Leuven. Recruiting at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-05.
Sponsored by Universitaire Ziekenhuizen KU Leuven · Phase 4, Interventional, and Treatment
Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis (IPAA) is considered the procedure of choice in patients with ulcerative colitis (UC) refractory to medical therapy or with neoplasia. The most common complication after IPAA is the development of pouchitis. Pouchitis is clinically characterized by variable symptoms including increased stool frequency, altered consistency, bloody stools, abdominal cramping, urgency, and incontinence. Symptomatic pouchitis longer than four weeks is considered chronic pouchitis.
The conventional treatment for acute and chronic pouchitis is antibiotics, such as metronidazole and ciprofloxacin. The disease course of antibiotic responsive pouchitis may evolve into antibiotic dependent (requiring antibiotic maintenance therapy) pouchitis and then antibiotic refractory (no response to antibiotic treatment) pouchitis. Although many patients respond to antibiotic therapy, there is also evidence that suggest that aberrant regulation of the mucosal immune system might play a part in the pathogenesis of pouchitis arising from an abnormal mucosal immune response to a dysbiosis of the pouch microbiota. If individuals fail to respond to antibiotics, anti-tumor necrosis factor (anti-TNF) agents and vedolizumab have been proposed for the treatment of chronic pouchitis.
Guselkumab, an interleukin-23 (IL-23) p19 subunit antagonist monoclonal antibody, is proven to be efficacious in patients with moderately-to-severely active UC. Efficacy of guselkumab in treating UC has been shown in multiple large clinical trials. However, patients with pouchitis were never the targeted population and were even often excluded from the trials.
Pouchitis becomes a chronic problem with a huge impact in the quality of life of these patients. The incidence of pouchitis has been rising in the last decades. This increase might be explained by a change in dietary habits of this population.
This open label single center trial at UZ Leuven aims to evaluate the efficacy and safety of guselkumab in the treatment of chronic antibiotic refractory pouchitis during a 48-week treatment period, with or without a dietary intervention. Twenty subjects with a proctocolectomy and IPAA for UC who have developed chronic or relapsing pouchitis will be enrolled.
Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis (IPAA) is considered the procedure of choice in patients with ulcerative colitis (UC) refractory to medical therapy or with neoplasia. The most common complication after IPAA is the development of pouchitis. Pouchitis is clinically characterized by variable symptoms including increased stool frequency, altered consistency, bloody stools, abdominal cramping, urgency, and incontinence. Between 50% and 80% of those with an IPAA will experience pouchitis symptoms at any given moment with 10% of patients developing a chronic antibiotic refractory pouchitis. Symptomatic pouchitis for less than four weeks is considered acute pouchitis, while symptomatic pouchitis longer than four weeks is considered chronic pouchitis. Additionally, relapsing pouchitis can also occur when there are three or more episodes per year.
The conventional treatment for acute and chronic pouchitis is antibiotics, such as metronidazole and ciprofloxacin. The clinical response of pouchitis to treatment with antibiotics such as metronidazole or ciprofloxacin, suggests that fecal stasis, Clostridium difficile infection, bacterial overgrowth or dysbiosis (qualitative or quantitative alterations in the bacterial communitiy) may be triggers. The disease course of antibiotic responsive pouchitis may evolve into antibiotic dependent (requiring antibiotic maintenance therapy) pouchitis and then antibiotic refractory (no response to antibiotic treatment) pouchitis. Although many patients respond to antibiotic therapy, there is also evidence that suggest that aberrant regulation of the mucosal immune system might play a part in the pathogenesis of pouchitis arising from an abnormal mucosal immune response to a dysbiosis of the pouch microbiota. If individuals fail to respond to antibiotics, anti-tumor necrosis factor (anti-TNF) agents and vedolizumab have been proposed for the treatment of chronic pouchitis. Recently, vedolizumab has been shown to be efficacious in treating chronic pouchitis with remission rates of 31% at week 14. Nevertheless, the treatment of chronic pouchitis remains an unmet need for patients with inflammatory bowel diseases (IBD).
Guselkumab, an interleukin-23 (IL-23) p19 subunit antagonist monoclonal antibody, is proven to be efficacious in patients with moderately-to-severely active UC. In the phase II GALAXI 1 trial (309 patients with UC, 2020), intravenous treatment with 200 mg, 600 mg or 1,200 mg guselkumab at weeks 0, 4 and 8 showed significantly greater reductions from baseline CDAI, outcomes of clinical response, clinical remission, Patient-Reported Outcome-2 (PRO-2) remission, clinical biomarker response and endoscopic response at week 12 compared with intravenous placebo. The QUASAR study (313 patients with UC, 2022), a Phase 2b/3 randomized, double-blind, placebo-controlled trial, demonstrated superiority of guselkumab to placebo for clinical response during induction at week 12 in patients with UC. Guselkumab also met key secondary endpoints of clinical remission, symptomatic remission, endoscopic improvement, and histo-endoscopic mucosal improvement. The efficacy and safety of guselkumab in patients with UC were further studied in the exploratory Phase 2a VEGA trial (214 patients with UC, 2023) evaluating combination treatment of guselkumab and golimumab during induction. Combination therapy was significantly more effective than either drug alone for clinical remission and endoscopic improvement. A meta-analysis (36 studies with 14270 patients with UC, 2024) comparing the relative efficacy of biologics and small molecules, proved Guselkumab to rank high in achieving clinical remission, endoscopic improvement and remission, and histological remission in patients with moderate to severe UC. Efficacy of guselkumab in treating UC has been shown in multiple large clinical trials. However, patients with pouchitis were never the targeted population and were even often excluded from the trials.
Pouchitis becomes a chronic problem with a huge impact in the quality of life of these patients. The incidence of pouchitis has been rising in the last decades. This increase might be explained by a change in dietary habits of this population. Interestingly, lower fruit consumption has been associated with higher risk of pouchitis. Moreover, food colorants have been associated with colitis in mice with higher IL-23 expression.
This open label single center trial at UZ Leuven aims to evaluate the efficacy and safety of guselkumab in the treatment of chronic antibiotic refractory pouchitis during a 48-week treatment period, with or without a dietary intervention. Twenty subjects with a proctocolectomy and IPAA for UC who have developed chronic or relapsing pouchitis will be enrolled.
50 studies on the registry are indexed under Pouchitis; 12 are open to participants now.
This study's planned enrollment of 20 is close to the median of 20 across 42 interventional studies indexed under Pouchitis.
Browse Pouchitis studies →Universitaire Ziekenhuizen KU Leuven is the lead sponsor of 963 studies on the registry; 267 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Participant with a proctocolectomy and IPAA for UC who heveloped chronic or relapsing pouchitis, defined as mPDAI score ≥5 and a minimum endoscopic subscore of 2 (outside the staple or suture line) with either:
All participants that are considered for Trial participation, per the above criteria will be documented via applicable log forms in Investigator Site File (including Screen Failures).
Exclusion Criteria:
Participants who meet one or more of the above exclusion criteria must not proceed to be enrolled/randomized in the Trial and will be identified via applicable log forms in Investigator Site File.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All patients will receive guselkumab 400 mg intravenous at week 0, week 4, and week 8, followed by subcutaneous guselkumab 200 mg at week 12, week 16, week 20, week 24, week 28, week 32, week 36, week 40, week 44, and week 48. All subjects will receive concomitant antibiotic treatment with ciprofloxacin 500mg twice daily from randomization through week 4.
Drug: Guselkumab
All patients will receive guselkumab 400 mg intravenous at week 0, week 4, and week 8, followed by subcutaneous guselkumab 200 mg at week 12, week 16, week 20, week 24, week 28, week 32, week 36, week 40, week 44, and week 48. All subjects will receive concomitant antibiotic treatment with ciprofloxacin 500mg twice daily from randomization through week 4. Subjects randomized to the group with the dietary intervention will be advised to follow a low-UPF, high-fruit diet. Patients will be instructed to restrict the intake of NOVA 4 food products during the first 16 weeks of the trial, and to increase the intake of fruits (minimum 3 servings per day) during the full trial. Dietary education will be provided by certified IBD dietitians, lists of products to avoid, and week menu's will also be provided to increase dietary adherence. Dietary information will be collected with food records and food frequency questionnaires.
Drug: Guselkumab · Other: Diet
All patients will receive guselkumab 400 mg intravenous at week 0, week 4, and week 8, followed by subcutaneous guselkumab 200 mg at week 12, week 16, week 20, week 24, week 28, week 32, week 36, week 40, week 44, and week 48. All subjects will receive concomitant antibiotic treatment with ciprofloxacin 500mg twice daily from randomization through week 4.
Also known as: Tremfya
Subjects randomized to the group with the dietary intervention will be advised to follow a low-UPF, high-fruit diet. Patients will be instructed to restrict the intake of NOVA 4 food products during the first 16 weeks of the trial, and to increase the intake of fruits (minimum 3 servings per day) during the full trial. Dietary education will be provided by certified IBD dietitians, lists of products to avoid, and week menu's will also be provided to increase dietary adherence. Dietary information will be collected with food records and food frequency questionnaires.
percentage of subjects achieving clinical remission after 16 weeks of treatment with guselkumab with/without diet
the percentage of subjects with chronic or recurrent pouchitis achieving clinical remission (mPDAI score \<5 and a reduction of overall score by ≥2 points from Baseline) after 16 weeks of treatment with guselkumab compared to 16 weeks of guselkumab and a dietary intervention.
Time frame: 16 weeks
percentage of subjects achieving clinical remission after 48 weeks
The percentage of subjects achieving clinical remission (mPDAI score \<5 and a reduction of overall score by ≥2 points from Baseline) after 48 weeks in both groups
Time frame: 48 weeks
percentage of subjects achieving antibiotic free clinical remission by week 16 and 48
The percentage of subjects achieving antibiotic free clinical remission by week 16 and 48
Time frame: week 16 and week 48
percentage of subjects achieving partial response after 16 and 48 weeks
The percentage of subjects achieving partial response (reduction of mPDAI score by ≥2 points from Baseline) after 16 and 48 weeks in both groups
Time frame: week 16 and week 48
Time to clinically relevant remission
Time to clinically relevant remission in both groups
Time frame: 48 weeks
Change in mPDAI endoscopic subscore at Week 16 and 48
Change in mPDAI endoscopic subscore at Week 16 and 48 compared to Baseline in both groups
Time frame: baseline, week 16 and week 48
Change in mPDAI histologic subscore at Week 16 and 48
Change in mPDAI histologic subscore at Week 16 and 48 compared to Baseline in both groups
Time frame: baseline, week 16 and week 48
Change in total mPDAI score at Week 16 and 48
Change in total mPDAI score at Week 16 and 48 compared to Baseline in both groups
Time frame: baseline, week 16 and week 48
percentage of subjects achieving a flare after initial response
The percentage of subjects achieving a (endoscopic proven) flare after initial response in both groups
Time frame: 48 weeks
Microbiota Metagenomic profiling at Week 8, 16, 24, 32, 40 and 48
Microbiota Metagenomic profiling (changes in intestinal microbiota) at Week 8, 16, 24, 32, 40 and 48 compared to Baseline in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Changes in IL-23p19 expression in the tissue at Week 16 and 48
Changes in IL-23p19 expression in the tissue at Week 16 and 48 compared to Baseline in both groups
Time frame: baseline, week 16 and week 48
Statistical association between IL-23p19 expression and response to therapy
Statistical association between IL-23p19 expression and response to therapy in both groups
Time frame: 48 weeks
Food record and food frequency questionnaire
Food record and food frequency questionnaire in the group with the dietary intervention
Time frame: 48 weeks
adverse event assessment of interventions
adverse event assessment of the interventions
Time frame: 48 weeks
questionnaire about diet tolerability
questionnaire about tolerability of the prescribed diet in the group with the dietary intervention
Time frame: 48 weeks
Time to relapse of pouchitis symptoms and number of relapses
Time to relapse of pouchitis symptoms and number of relapses in both groups
Time frame: 48 weeks
Change in CRP at Week 8, 16, 24, 32, 40 and 48
Change in CRP at Week 8, 16, 24, 32, 40 and 48 compared to Baseline in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Change in faecal calprotectin at Week 8, 16, 24, 32 and 48
Change in faecal calprotectin at Week 8, 16, 24, 32 and 48 compared to Baseline in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Evolution of guselkumab serum levels
Evolution of guselkumab serum levels between Baseline and Week 8, 16, 24, 32, 40 and 48 in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Evolution of anti-guselkumab antibodies
Evolution of anti-guselkumab antibodies between Baseline and Week 8, 16, 24, 32, 40 and 48 in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Statistical correlation of guselkumab serum levels and anti-guselkumab antibodies with clinical, endoscopic and histological outcomes
Statistical correlation of guselkumab serum levels and anti-guselkumab antibodies with clinical, endoscopic and histological outcomes between Baseline and Week 8, 16, 24, 32, 40 and 48 in both groups
Time frame: baseline, week 8, 16, 24, 32, 40 and week 48
Plan to share: No
No publications or documents are linked to this record.
Started Apr 2026 (actual). Primary completion is estimated for May 2028, 25 months after the start.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Universitaire Ziekenhuizen KU Leuven →