PouchitisPhase 4GUARDIANNCT06916390
GUselkumAb inteRvention and DIet evaluAtioN for Pouchitis
A Phase 4 study testing Guselkumab and Diet in people with Pouchitis, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pouchitis
- What is being tested?
- Guselkumab and Diet
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteBelgium
- Study dates
- 23 Apr 2026to 30 May 2029
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
- At least 18 years of age at the time of signing the Informed Consent Form (ICF)
- Use of highly effective methods of birth control; defined as those that, alone or in combination, result in low failure rate (i.e., less than 1% per year) when used consistently and correctly; such as implants, injectables, combined oral contraceptives, some IUDs, true sexual abstinence (i.e. refraining from heterosexual intercourse during the entire period of risk associated with the Trial treatment(s)) or commitment to a vasectomised partner.
- 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:
- ≥2 recurrent episodes within 1 year prior to the screening visit, each treated with ≥2 weeks of antibiotic or other prescription therapy, or
- patients treated with maintenance antibiotic therapy taken continuously for four consecutive weeks before the screening visit and who are refractory to this antibiotic therapy, or
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- previously failure of another biologic therapy to treat chronic pouchitis.
- The subject agrees to take ciprofloxacin (500 mg twice daily) on Day 1 and through Week 4, regardless of the previous treatment and to stop any previous antibiotic therapy on Day 1 of the study. For patients who did previously not tolerate quinolone therapy, an alternative antibiotic therapy between Day 1 and Week 4 with metronidazole (500 mg three times a day) will be allowed. (Additional courses of antibiotics will be allowed, as needed, for flares after Week 16.)
- 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).
Who cannot join
- Crohn's disease (CD), CD-related complications of the pouch (pouch fistula, pouch strictures, ulcerations in the pre-pouch ileum without pouchitis), irritable pouch syndrome (IPS), isolated or predominant cuffitis, infectious pouchitis, diverting ostomy or mechanical complications of the pouch
- Previous treatment with an anti-IL12/23 or an anti-IL23 antibody
- Any investigational or approved biologic agent within 30 days of screening
- Nonbiologic investigational therapy or JAK inhibitors within 30 days prior to screening
- Active or untreated latent tuberculosis (TB). In case of a newly identified positive diagnostic TB test result (defined as a positive tuberculin skin test) , active TB has to be ruled out and appropriate treatment for latent TB has to be initiated for a minimum of 4 weeks prior to the first administration of study medication.
- Chronic hepatitis B virus (HBV)* infection, chronic hepatitis C virus (HCV) infection, a known history of human immunodeficiency virus (HIV) infection (or is found to be seropositive at screening) or subject is immunodeficient (e.g., due to organtransplantation, history of common variable immunodeficiency, etc). * Subjects who are positive for hepatitis B virus surface antigen (HBsAg) will be excluded. For subjects who are negative for HBsAg but are positive for either surface antibodiesand/or core antibodies, HBV DNA polymerase chain reaction will be performed and if anytest result meets or exceeds detection sensitivity, the subject will be excluded. If subject is HCV antibody positive, then a viral load test will be performed. If the viralload test is positive then the subject will be excluded.
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- Active severe infection (eg sepsis, cytomegalovirus, listeriosis or C. difficile)
- The subject has allergies to and/or contraindications for ciprofloxacin and metronidazole
- Participant has a history of malignancy or current malignancy, except for the following: adequately treated non-metastatic basal cell skin cancer, squamous cell skin cancer and cervical carcinoma in situ. Subjects with a remote history of malignancy (e.g., >10 years since completion of curative therapy without recurrence) will be considered based on the nature of the malignancy and the therapy.
- Any disorder or laboratory abnormalities which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol.
- Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial (see list in 5.3).
- Female who is pregnant, breast-feeding or intends to become pregnant before, during, or within 15 weeks after the last dose of study drug; or intending to donate ova during such time period or is of child-bearing potential and not using an adequate, highly effective contraceptive or males who want to make their partner pregnant or intends to donate sperm during the course of this study or for 18 weeks after the last dose of study drug
- Participation in another interventional Trial with an investigational medicinal product (IMP) or device.
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
university hospitals Leuven
Leuven, Vlaams-Brabant, 3000
Joao Sabino, Prof Dr, 016341770 ext. +32, joao.sabino@uzleuven.be
About this study
Official title: Guselkumab Intervention and Diet Evaluation for Pouchitis
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.
Read more
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.
Read the detailed description
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.
- Conditions
- Pouchitis
- Being tested
- Guselkumab, Diet
- Keywords
- pouchitis, guselkumab, high fruit diet, low intake of NOVA 4 food products
- Medical subject headings
- Pouchitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GuselkumabDrug
Also called Tremfya
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.
DietOther
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.
| Study group | Role | What they receive |
|---|---|---|
| intervention with guselkumab | Active comparator | 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. Receives: Drug: Guselkumab |
| intervention with guselkumab and diet | Active comparator | 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. Receives: Drug: Guselkumab; Other: Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 16 weeks
Secondary outcomes (14)
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
Measured: 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
Measured: 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
Measured: week 16 and week 48
Time to clinically relevant remission
Time to clinically relevant remission in both groups
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 48 weeks
Food record and food frequency questionnaire
Food record and food frequency questionnaire in the group with the dietary intervention
Measured: 48 weeks
adverse event assessment of interventions
adverse event assessment of the interventions
Measured: 48 weeks
questionnaire about diet tolerability
questionnaire about tolerability of the prescribed diet in the group with the dietary intervention
Measured: 48 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Apr 2025
- Study start23 Apr 2026
- Primary completion30 May 2028 (estimated)
- Study completion30 May 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PouchitisStudies of the same condition, open and under way.
- More trials run by Universitaire Ziekenhuizen KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- This will be a prospective, open label, parallel group, single center, randomized, (1:1) exploratory, efficacy trial at UZ Leuven.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitaire Ziekenhuizen KU Leuven
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06916390
- Sponsor's protocol ID
- GUARDIAN
- Acronym
- GUARDIAN
- Status last verified
- Apr 2026
- First submitted
- 21 Mar 2025
- Last updated
- 5 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Guselkumab Intervention and Diet Evaluation for Pouchitis
- ClinicalTrials.gov ID
- NCT06916390
- Acronym / sponsor ID
- GUARDIAN / GUARDIAN
- Conditions
- Pouchitis
- Keywords
- pouchitis, guselkumab, high fruit diet, low intake of NOVA 4 food products
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Universitaire Ziekenhuizen KU LeuvenUniversity, hospital or other
- Study start
- 23 Apr 2026 (actual)
- Primary completion
- 30 May 2028 (estimated)
- Study completion
- 30 May 2029 (estimated)
- First posted
- 8 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This will be a prospective, open label, parallel group, single center, randomized, (1:1) exploratory, efficacy trial at UZ Leuven.
| Arm | Type | Receives |
|---|---|---|
| intervention with guselkumab | Active comparator | Drug: GuselkumabAll 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. |
| intervention with guselkumab and diet | Active comparator | Drug: Guselkumab, Other: DietAll 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
- At least 18 years of age at the time of signing the Informed Consent Form (ICF)
- Use of highly effective methods of birth control; defined as those that, alone or in combination, result in low failure rate (i.e., less than 1% per year) when used consistently and correctly; such as implants, injectables, combined oral contraceptives, some IUDs, true sexual abstinence (i.e. refraining from heterosexual intercourse during the entire period of risk associated with the Trial treatment(s)) or commitment to a vasectomised partner.
- 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:
- The subject agrees to take ciprofloxacin (500 mg twice daily) on Day 1 and through Week 4, regardless of the previous treatment and to stop any previous antibiotic therapy on Day 1 of the study. For patients who did previously not tolerate quinolone therapy, an alternative antibiotic therapy between Day 1 and Week 4 with metronidazole (500 mg three times a day) will be allowed. (Additional courses of antibiotics will be allowed, as needed, for flares after Week 16.)
Key exclusion criteria (14 listed)
- Crohn's disease (CD), CD-related complications of the pouch (pouch fistula, pouch strictures, ulcerations in the pre-pouch ileum without pouchitis), irritable pouch syndrome (IPS), isolated or predominant cuffitis, infectious pouchitis, diverting ostomy or mechanical complications of the pouch
- Previous treatment with an anti-IL12/23 or an anti-IL23 antibody
- Any investigational or approved biologic agent within 30 days of screening
- Nonbiologic investigational therapy or JAK inhibitors within 30 days prior to screening
- Active or untreated latent tuberculosis (TB). In case of a newly identified positive diagnostic TB test result (defined as a positive tuberculin skin test) , active TB has to be ruled out and appropriate treatment for latent TB has to be initiated for a minimum of 4 weeks prior to the first administration of study medication.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GuselkumabAlso: TremfyaAll 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 | intervention with guselkumab, intervention with guselkumab and diet |
| DietSubjects 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. | Other | intervention with guselkumab and diet |
Primary outcome
percentage of subjects achieving clinical remission after 16 weeks of treatment with guselkumab with/without diet
Time frame: 16 weeks
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.
14 secondary outcomes
percentage of subjects achieving clinical remission after 48 weeks
Time frame: 48 weeks
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
Time frame: week 16 and week 48
Time to clinically relevant remission
Time frame: 48 weeks
Change in mPDAI endoscopic subscore at Week 16 and 48
Time frame: baseline, week 16 and week 48
Change in mPDAI histologic subscore at Week 16 and 48
Time frame: baseline, week 16 and week 48
Change in total mPDAI score at Week 16 and 48
Time frame: baseline, week 16 and week 48
percentage of subjects achieving a flare after initial response
Time frame: 48 weeks
Microbiota Metagenomic profiling at Week 8, 16, 24, 32, 40 and 48
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
Time frame: baseline, week 16 and week 48
Statistical association between IL-23p19 expression and response to therapy
Time frame: 48 weeks
Food record and food frequency questionnaire
Time frame: 48 weeks
adverse event assessment of interventions
Time frame: 48 weeks
questionnaire about diet tolerability
Time frame: 48 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 May 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Guselkumab and Diet in people with Pouchitis, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Joao Sabino, Prof Dr (+32 ext. 016341770, joao.sabino@uzleuven.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
percentage of subjects achieving clinical remission after 16 weeks of treatment with guselkumab with/without diet (time frame: 16 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 May 2026.