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NCT Number: NCT06896305

Impact of Exclusion Diet in Addition to Anti-TNF Therapy in Crohn's Disease and Ulcerative Colitis: a Prospective, Randomized, Double-arm, Open-label Study

This clinical study protocol aims to prospectively compare the efficacy of standard therapy with anti-TNF agents combined with the Crohn's Disease Exclusion Diet (CDED) versus anti-TNF therapy alone in adult patients with active Crohn's disease or ulcerative colitis.

The study will involve patients starting therapy with anti-TNF agents due to active Crohn's disease or ulcerative colitis as per standard clinical practice and in accordance with European (ECCO) guidelines.

One group will receive standard medical therapy only, the other will additionally receive dietary advice on how to adhere on a specific exclusion diet, the CDED.

By prospectively evaluating the impact of this combined approach, the study seeks to provide evidence on whether CDED can improve response to treatment and therefore improve quality of life for patients with Crohn's disease and ulcerative colitis.

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Key information

Conditions

Ulcerative Colitis (UC) Colitis Colitis, Ulcerative Colonic Diseases Crohn Disease Crohn Disease (CD) Digestive System Diseases Gastroenteritis Gastrointestinal Diseases Inflammatory Bowel Diseases Intestinal Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

This is a prospective interventional, single-center, double-group, open-label study.

Primary objective is to compare the efficacy of CDED in addition to anti-TNF therapy in active CD and UC versus anti-TNF therapy alone.

Secondary objective are:

  • Endoscopic response
  • Endoscopic remission
  • Early and late efficacy and persistence of benefits
  • Biochemical response
  • Sonographic improvement
  • Tolerability and compliance to the Crohn's Disease ExclusionDiet (CDED)
  • Quality of life-Safety of the combination of biological therapy and CDED. The subjects considered are adult patients diagnosed with moderate-to-severe Crohn's disease or moderate-to-severe ulcerative colitis who are starting therapy with an approved anti-TNF agent (infliximab and adalimumab for both UC and CD, and golimumab only for UC).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participant is willing and able to give informed consent forparticipation in the study
  • Males or Females, Adults aged 18 years or older
  • Confirmed diagnosis of moderate-to-severe Crohn's disease orulcerative colitis
  • Patients who are planned to start anti-TNF therapy
  • Ability and willingness to comply with the Crohn's DiseaseExclusion Diet (CDED)

Exclusion criteria

  • Patients with undetermined inflammatory bowel disease
  • Patients with metabolic or gastrointestinal conditions that couldinterfere or are incompatible with the study intervention (e.i.celiac disease, diabetes etc)
  • Patients with a body-mass index lower than 17 or greater than30
  • Patients who previously underwent intestinal resectionirrespective of cause
  • Patients currently on exclusive enteral nutrition (EEN)
  • Patients who have previously used or are currently adhering toCDED
  • Pregnant or breastfeeding women
  • Patients with a history of severe allergic reactions orintolerance to any food recommended in CDED
  • Patients with significant comorbidities that may interfere withthe study or pose a risk to the participant
  • Inability or unwillingness to comply with study protocols orfollow-up schedules

Treatment and study plan

CDED (Crohn's Disease Exclusion Diet) in addition to anti-TNF therapy

Combination Product

Patients in the experimental group will receive professional dietary advice on how to adhere to CDED for 12 weeks, in addition to anti-TNF therapy while patients in the control group will receive only anti-TNF therapy for the entire duration of the study.

Diet adherence is completely voluntary and is not enforced in any way. CDED is divided into 3 phases, the first two, grouped as the induction phase, with 6 weeks of strict diet and 6 weeks to gradual food reintroduction, followed by 12 weeks of patients follow-up.

Five foods (chicken, eggs, potatoes, apple and bananas) are permitted at the start of the diet; the patient can then choose to consume a range of permitted foods at will, the variability of which increases after the first six weeks

anti-TNF therapy

Drug

The control group will receive only anti-TNF therapy as per standard of care. This therapy is recommended by guidelines and is the cornerstone of treatment of Crohn's disease and ulcerative colitis.

Primary outcomes

  1. Efficacy of CDED in addition to anti-TNF therapy in active CD and UC versus anti-TNF therapy

    Time frame: Week 14/16

    Rate of symptomatic remission (Harvey - Bradshaw Index <5 for CD or Partial Mayo Score <2) for UC

Secondary outcomes

  1. Endoscopic response and endoscopic remission

    Time frame: Week 24

    • Rate of endoscopic response for CD (SES-CD score reduction of 25% or more and of 50% or more from baseline) and for UC (endoscopic Mayo score reduction of at least 1 or more points)
    • Rate of endoscopic remission for CD (SES-CD score ≤3) and for UC (Mayo endoscopic score ≤1)

  2. Early and late efficacy and persistence of benefits

    Time frame: Week 6/ Week 24

    Rate of symptomatic remission (Harvey- Bradshaw Index < 5 and Partial Mayo Score <2) at week 6 and 24

  3. Biochemical response

    Time frame: Week 6, 14/16, 24

    • Change in C-reactive protein (CRP) levels from baseline
    • Change in fecal calprotectin levels from baseline

  4. Sonographic improvement

    Time frame: Week 6, 14/16, 24

    • Change in BUSS (for CD) or MUC (for UC) from baseline
    • Rate of patients in transmural response (bowel wall thickness ≤3mm and no increase in bowel wall flow)

  5. Tolerability and compliance to the Crohn's Disease Exclusion Diet (CDED)

    Time frame: Week 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

    Percentage of patients self-reporting adherence to CDED

  6. Quality of life assessed using the Short-IBD-Q questionnaire

    Time frame: Week 14/16, week 24

    Change in Short-IBDQ questionnare score. Quality of life will be assessed using the validated Italian translation of the Short-IBD-Q questionnaire

  7. Safety of the combination of biological therapy and CDED

    Time frame: From baseline until the end of the study

    Incidence and type of adverse events during the study period

Study contacts

Contact information is provided by the study sponsor or research team.

Annunziata Bruno, MS

CONTACT

[email protected]

+39 02 2643 2756

Tommaso Lorenzo Parigi, MD

CONTACT

[email protected]

+39 02 2643 2756

Sponsors and collaborators

Lead sponsor

IRCCS Ospedale San Raffaele

Other

Registry information

Official study title

Impact of Diet on the Effectiveness of Anti-TNF Therapy in Inflammatory Bowel Disease: a Prospective, Randomized, Double Arm, Open-label Study

Acronym: IDEA-TNF

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Mar 26, 2025
Registry last updated
Jan 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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