Predictive Efficacy of Fecal Calprotectin Assay by Magnetic Particle Chemiluminescence for Mucosal Healing in Moderate-to-Severe Ulcerative Colitis Patients Undergoing Initial Biologic Therapy（PRECAL） (PRECAL)

Predictive Efficacy of Fecal Calprotectin Assay by Magnetic Particle Chemiluminescence for Mucosal Healing in Moderate-to-Severe Ulcerative Colitis Patients Undergoing Initial Biologic Therapy: A Prospective, Multicenter, Observational Clinical Study

This is a national prospective, multicenter, observational study. A total of 200 eligible patients will be enrolled from 10 hospitals across the country. Inclusion criteria are as follows: aged ≥ 18 years; diagnosed with moderate-to-severe active ulcerative colitis (UC); disease extent classified as E2 or E3; receiving biologic therapy for the first time; and having a confirmed UC diagnosis for more than 3 months. The follow-up period lasts 30-32 weeks. Six scheduled follow-up visits will be conducted at baseline, weeks 2-4, 6-8, 14-16, 22-24, and 30-32 after enrollment. The study endpoints are defined as: endoscopic mucosal healing (Mayo endoscopic score = 0 for UC), clinical judgment of inadequate response to current biologic therapy (i.e., continued treatment is unlikely to achieve mucosal healing and thus treatment switching or combined medication is required), or completion of the 30-32-week follow-up. The primary objective is to determine the cutoff value and predictive efficacy of the early (Weeks 2-4) reduction in fecal calprotectin (FC) measured by magnetic particle chemiluminescence assay for predicting mucosal healing in moderate-to-severe UC patients initiating biologic therapy.

Study Overview

• Status: Enrolling by invitation
• Conditions: Ulcerative Colitis (UC)
• Intervention / Treatment: Diagnostic test: fecal calprotectin test

Detailed Description

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease that mainly affects the rectum and colon. It is characterized by frequent relapse and protracted course. Its incidence has been rising rapidly, imposing a substantial economic burden on both patients and society. Biologic agents serve as key therapeutic options for UC and are widely used in the management of patients with moderate-to-severe disease. Mucosal healing (MH) is a core therapeutic goal for UC. Endoscopy is the primary modality to assess endoscopic MH, yet it is an invasive examination.

Fecal calprotectin (FC) is a specific biomarker for intestinal inflammation, which can accurately reflect the inflammatory status of the gut and acts as an ideal non-invasive biomarker for patients with UC. A large number of existing studies have demonstrated that FC is strongly correlated with clinical disease activity, endoscopic findings and histological parameters, highlighting its great value in disease assessment.

Magnetic particle chemiluminescence assay features high sensitivity, rapid detection, wide linear range, excellent precision and accuracy, as well as high degree of automation. It enables full-course monitoring of FC levels across mild, moderate and severe inflammatory stages as well as disease remission, providing evidence for evaluating therapeutic efficacy and optimizing treatment regimens. Hence, it is an optimal method for detecting FC concentrations.

This is a national prospective, multicenter, observational study. Eligible participants are patients aged 18 years or older with moderate-to-severe active UC, disease extent classified as Montreal E2 or E3, newly initiated biologic therapy, and a confirmed UC diagnosis of more than 3 months. The total follow-up duration is 30 to 32 weeks. During follow-up, stool samples are collected for FC measurement, along with clinical data and endoscopic results of the enrolled patients.

The study endpoints are defined as endoscopic mucosal healing, clinically confirmed inadequate response to the current biologic therapy (where continued treatment is unlikely to achieve mucosal healing, necessitating treatment switching or combined medication), or completion of the 30-32-week follow-up.

The primary objective is to determine the cutoff value and predictive performance of the early (Weeks 2-4) reduction in FC measured by magnetic particle chemiluminescence assay for predicting mucosal healing in moderate-to-severe UC patients receiving initial biologic therapy.

The secondary objectives are as follows:

1. To identify the cutoff value and predictive performance of the early (Weeks 2-4) FC reduction detected via magnetic particle chemiluminescence assay for predicting sustained clinical response in moderate-to-severe UC patients on initial biologic therapy;
2. To explore the cutoff value and predictive performance of the early (Weeks 2-4) FC reduction for predicting sustained endoscopic remission in the above patient population;
3. To analyze the dynamic correlation between FC levels measured by magnetic particle chemiluminescence assay and clinical disease activity;
4. To assess the correlation between FC levels and endoscopic disease activity;
5. To establish a predictive model for mucosal healing at Weeks 30-32 in UC patients by combining symptom scores, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), FC levels and their reduction ranges.

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

Study Locations

• China
  • Dalian, China, 116023
    • The Second Hospital of Dalian Medical University
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100044
      • Peking University People's Hospital
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 401121
      • Chongqing General Hospital
  • Guangdong
    • Shenzhen, Guangdong, China, 518101
      • Shenzhen Hospital, Southern Medical University
  • Hubei
    • Wuhan, Hubei, China, 430022
      • Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
  • Jiangsu
    • Nanjing, Jiangsu, China, 210009
      • Zhongda Hospital, Southeast University
  • Liaoning
    • Shengyang, Liaoning, China, 110004
      • Shengjing Hospital of China Medical University,
  • Shandong
    • Qingdao, Shandong, China, 266035
      • Qilu Hospital (Qingdao), Shandong University
  • Shanxi
    • Xi’an, Shanxi, China, 710038
      • Tangdu Hospital, Air Force Medical University
    • Xi’an, Shanxi, China, 710077
      • The First Affiliated Hospital of Xi'an Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with ulcerative colitis who are aged ≥ 18 years, have moderate-to-severe disease activity, present with disease extent E2 or E3, receive biologic therapy for the first time, and have a confirmed diagnosis of ulcerative colitis for more than 3 months

Description

Inclusion Criteria

• Aged ≥ 18 years;
• Patients with ulcerative colitis receiving initial biologic therapy;
• Confirmed diagnosis of ulcerative colitis for more than 3 months;
• Moderate-to-severe disease activity;
• Disease extent classified as E2 or E3;
• Voluntarily signed the informed consent form and agreed to participate in this study.

Exclusion Criteria

• Aged under 18 years;
• Patients who have previously received biologic therapy;
• Patients with ulcerative colitis of disease extent E1;
• Pregnant or lactating women;
• Patients with contraindications to biologic agents;
• Patients deemed unsuitable for this clinical study by clinical judgment.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
moderate-to-severe UC patients; Patients with ulcerative colitis who are aged ≥ 18 years, have moderate-to-severe disease activity, present with disease extent E2 or E3, receive biologic therapy for the first time, and have a confirmed diagnosis of ulcerative colitis for more than 3 months	Diagnostic test: fecal calprotectin test; Fecal calprotectin detection by magnetic particle chemiluminescence assay

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cut-off value and predictive efficacy of the early decline in fecal calprotectin for mucosal healing	Mucosal healing was defined as an endoscopic subscore of 0 according to the modified Mayo score system for assessing ulcerative colitis disease activity	From enrollment to at the end of 30-32 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cutoff value and predictive performance of fecal calprotectin reduction for predicting sustained clinical response	clinical symptom remission is defined as a score of 0 for both Stool Frequency (SF) and Rectal Bleeding(RB) in the Mayo score; or a score of 0 for RB, plus an SF score of ≤1 with a reduction of at least 1 point from baseline	From enrollment to at the end of 30-32 weeks follow-up
Cutoff value and predictive performance of fecal calprotectin reduction for predicting sustained endoscopic remission	Endoscopic remission is defined as an endoscopic subscore of 0 or 1 in the Mayo score (excluding the finding of mucosal friability)	From enrollment to at the end of 30-32 weeks follow-up
Dynamic correlation between fecal calprotectin levels and clinical disease activity	Fecal calprotectin and Mayo score data will be collected at each follow-up time point to analyze their dynamic correlation	From enrollment to at the end of 30-32 weeks follow-up
Correlation between fecal calprotectin levels and endoscopic disease activity.	Fecal calprotectin and Mayo endoscopic subscore data will be collected at each follow-up time point to assess their correlation.	From enrollment to at the end of 30-32 weeks follow-up

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Predictive model for mucosal healing at Weeks 30-32 in UC patients by combining symptom scores, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), fecal calprotectin levels and their decreasing ranges	Multivariate regression analysis will be performed using patients' demographic data, disease characteristics, medication information, Mayo scores, ESR, CRP and fecal calprotectin levels, so as to develop a predictive model for mucosal healing at Weeks 30-32 among moderate-to-severe ulcerative colitis patients treated with biologic agents.	From enrollment to at the end of 30-32 weeks follow-up

Collaborators and Investigators

• Sponsor: Tang-Du Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 18, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): October 30, 2027

Study Registration Dates

• First Submitted: June 28, 2026
• First Submitted That Met QC Criteria: July 20, 2026
• First Posted (Actual): July 23, 2026

Study Record Updates

• Last Update Posted (Actual): July 23, 2026
• Last Update Submitted That Met QC Criteria: July 20, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: ulcerative colitis; mucosal healing; Fecal calprotectin; Biological agent
• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Colitis; Colitis, Ulcerative
• Other Study ID Numbers: FCTSTUDY001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No