Crohn DiseaseNCT07364734
Epidemiological Characteristics and Efficacy Evaluation of Difficult-To-Treat Crohn's Disease
An observational study of Crohn Disease, run by Xiang Gao at 1 site in China.
Trial summary
Difficult to treat Crohn's disease (DTT-CD) was defined by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) in 2023, which refers to CD patients with poor response to drug treatment and poor prognosis. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Crohn Disease
- How many people
- 1,400 participants
- Where
- 1 siteChina
- Study dates
- 1 Nov 2025to 30 Nov 2027
- How long will I take part?
- 1 Year
- Phase
- Observational
- 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 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with Crohn's disease who visited tertiary hospitals, including those newly diagnosed and those previously diagnosed.
Who may be able to join
- The diagnosis of Crohn's disease was confirmed;
- Patients aged 18-65;
- Informed consent was obtained voluntarily.
Who cannot join
- The diagnosis of CD was unclear;
- The clinical baseline data were missing seriously;
- Patients currently enrolled in clinical trials or receiving experimental drugs;
- Other contraindications to biologics or small molecule drugs (including active infection, pregnancy, etc.);
- Patients with short bowel syndrome;
- Patients with a small bowel or colostomy.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Sixth Affiliated Hospital, Sun Yat-sen University
Guangzhou, Guangdong, 510655
Xiang Gao, +86-020-38663423, gxiang@mail.sysu.edu.cn
About this study
Official title: Epidemiological Characteristics and Efficacy Evaluation of Refractory Crohn's Disease: a Multicenter, Prospective and Observational Cohort Study
Difficult to treat Crohn's disease (DTT-CD) was defined by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) in 2023, which refers to CD patients with poor response to drug treatment and poor prognosis. Foreign epidemiological studies have shown that DTT-CD accounts for 24.8% of all CD patients, and most of them are patients with advanced treatment failure according to more than two different mechanisms. Our previous retrospective data suggested that compared with foreign DTT-CD patients, there was no significant difference in the proportion of patients with advanced treatment failure due to more than two different mechanisms, but the proportion of patients with recurrence after two intestinal resection and complex anal fistula was increased. Therefore, this project aims to determine the current prevalence and epidemiological status of DTT-CD in China; To clarify the difference in efficacy and prognosis between DTT-CD patients and non DTT-CD patients using advanced treatment (including biological agents and small molecule drugs); Objective to evaluate the incidence and risk factors of non DTT-CD patients progressing to DTT-CD within 1 year. To further verify whether the domestic DTT-CD population is significantly different from the foreign population, and provide theoretical support for the selection of subsequent treatment options.
- Conditions
- Crohn Disease
- Keywords
- Difficult-To-Treat Crohn's Disease, Epidemiological Characteristics, Efficacy Evaluation
- Medical subject headings
- Crohn Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Total study population | The total study population included all CD patients who visited the Sixth Affiliated Hospital of Sun Yat sen University during the specified time period (November 2025 to January 2026), including newly diagnosed and previously diagnosed patients |
What is being measured
The primary outcome is the main question the study is designed to answer.
steroid-free remission
Compare the steroid-free clinical remission rates of patients with DTT-CD and non DTT-CD during the induction and maintenance periods in the patients using biologics or small molecule drugs. "Steroid-free" refers to patients who do not receive concomitant steroid medication.
Measured: From the beginning of enrollment to 1 year
Secondary outcomes (7)
Epidemiological status of Difficult-To-Treat Crohn's Disease
Calculate the proportion of DTT-CD patients in the total population
Measured: From the beginning of enrollment to three months later
Clinical reponse rate
Compare the clinical response rates of patients with DTT-CD and non DTT-CD during the induction and maintenance periods in the patients using biologics or small molecule drugs.
Measured: From the begining of enrollment to 1 year.
Clinical remission rate
Compare the clinical remission rates of patients with DTT-CD and non DTT-CD during the induction and maintenance periods in the patients using biologics or small molecule drugs.
Measured: From the begining of enrollment to 1 year
Endoscopic outcome
Compare the endoscopic outcomes of patients with DTT-CD and non DTT-CD during the induction and maintenance periods, including the endoscopic response rate, the endoscopic remission rate, and the mucusal healing rate in the patients using biologics or small molecule drugs.
Measured: From the begining of enrollment to 1 year
Ultrasound outcome
Compare the ultrasound outcomes of patients with DTT-CD and non DTT-CD during the induction and maintenance periods in the patients using biologics or small molecule drugs, including the transmural response rate and the transmural remission rate.
Measured: From the begining of enrollment to 1 year
Postoperative recurrence rate
Compare the postoperative recurrence rates of DTT-CD and non DTT-CD: postoperative recurrence is defined as the recurrence of clinical symptoms, or endoscopic mucosal ulcers, or imaging evidence of intestinal inflammation, etc.
Measured: From the begining of enrollment to 1 year
Safety differences
Compare the safety differences between DTT-CD and non-DTT-CD after one year of biologic therapy.
Measured: From the begining of enrollment to 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2026
- Study start1 Nov 2025
- Primary completion1 Nov 2027 (estimated)
- Study completion30 Nov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Crohn DiseaseStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 1,400 participants (estimated)
- Target duration
- 1 Year
Sponsor and investigators
- Lead sponsor
- Xiang Gao
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Xiang Gao, Sixth Affiliated Hospital, Sun Yat-sen University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07364734
- Sponsor's protocol ID
- 2025-ZSLYEC-556
- Status last verified
- Jan 2026
- First submitted
- 16 Jan 2026
- Last updated
- 23 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Epidemiological Characteristics and Efficacy Evaluation of Refractory Crohn's Disease: a Multicenter, Prospective and Observational Cohort Study
- ClinicalTrials.gov ID
- NCT07364734
- Acronym / sponsor ID
- 2025-ZSLYEC-556
- Conditions
- Crohn Disease
- Keywords
- Difficult-To-Treat Crohn's Disease, Epidemiological Characteristics, Efficacy Evaluation
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 1,400 participants (estimated)
- Lead sponsor
- Xiang GaoUniversity, hospital or other
- Study start
- 1 Nov 2025 (actual)
- Primary completion
- 1 Nov 2027 (estimated)
- Study completion
- 30 Nov 2027 (estimated)
- First posted
- 23 Jan 2026 (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.
Difficult to treat Crohn's disease (DTT-CD) was defined by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) in 2023, which refers to CD patients with poor response to drug treatment and poor prognosis. Foreign epidemiological studies have shown that DTT-CD accounts for 24.8% of all CD patients, and most of them are patients with advanced treatment failure according to more than two different mechanisms. Our previous retrospective data suggested that compared with foreign DTT-CD patients, there was no significant difference in the proportion of patients with advanced treatment failure due to more than two different mechanisms, but the proportion of patients with recurrence after two intestinal resection and complex anal fistula was increased. Therefore, this project aims to determine the current prevalence and epidemiological status of DTT-CD in China; To clarify the difference in efficacy and prognosis between DTT-CD patients and non DTT-CD patients using advanced treatment (including biological agents and small molecule drugs); Objective to evaluate the incidence and risk factors of non DTT-CD patients progressing to DTT-CD within 1 year. To further verify whether the domestic DTT-CD population is significantly different from the foreign population, and provide theoretical support for the selection of subsequent treatment options.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Year
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Total study population | – | –The total study population included all CD patients who visited the Sixth Affiliated Hospital of Sun Yat sen University during the specified time period (November 2025 to January 2026), including newly diagnosed and previously diagnosed patients |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with Crohn's disease who visited tertiary hospitals, including those newly diagnosed and those previously diagnosed.
Key inclusion criteria (3 listed)
- The diagnosis of Crohn's disease was confirmed;
- Patients aged 18-65;
- Informed consent was obtained voluntarily.
Key exclusion criteria (6 listed)
- The diagnosis of CD was unclear;
- The clinical baseline data were missing seriously;
- Patients currently enrolled in clinical trials or receiving experimental drugs;
- Other contraindications to biologics or small molecule drugs (including active infection, pregnancy, etc.);
- Patients with short bowel syndrome;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
steroid-free remission
Time frame: From the beginning of enrollment to 1 year
Compare the steroid-free clinical remission rates of patients with DTT-CD and non DTT-CD during the induction and maintenance periods in the patients using biologics or small molecule drugs. "Steroid-free" refers to patients who do not receive concomitant steroid medication.
7 secondary outcomes
Epidemiological status of Difficult-To-Treat Crohn's Disease
Time frame: From the beginning of enrollment to three months later
Clinical reponse rate
Time frame: From the begining of enrollment to 1 year.
Clinical remission rate
Time frame: From the begining of enrollment to 1 year
Endoscopic outcome
Time frame: From the begining of enrollment to 1 year
Ultrasound outcome
Time frame: From the begining of enrollment to 1 year
Postoperative recurrence rate
Time frame: From the begining of enrollment to 1 year
Safety differences
Time frame: From the begining of enrollment to 1 year
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 23 Jan 2026.
- Individual participant dataSharing planned: Undecided
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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?
An observational study of Crohn Disease, run by Xiang Gao at 1 site in China.
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 3 inclusion and 6 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 23 Jan 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 China. 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.
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 Xiang Gao (+86-020-38663423, gxiang@mail.sysu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
steroid-free remission (time frame: From the beginning of enrollment to 1 year). 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 23 Jan 2026.