A Study to Evaluate the Efficacy, Safety, Tolerability and Pharmacokinetics of PTT-621 in Patients With Moderately to Severely Active Ulcerative Colitis

NCT07747155 | Not Yet Recruiting Phase 2

• 1 other identifier: PTT-621-201
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This Phase IIa, multicenter, single-arm trial evaluates the efficacy, safety, tolerability, and pharmacokinetics of PTT-621 tablets in adults (18-70 years) with moderate-to-severe active ulcerative colitis (UC) who have inadequate response/intolerance to standard therapies. Participants receive PTT-621 for 12 weeks. The primary endpoint is the proportion of participants achieving endoscopic improvement at Week 12. Secondary endpoints include safety, clinical remission, clinical response, symptom response, pharmacokinetics, and inflammatory biomarkers. The study is sponsored by Pyrotech Therapeutics, with ethical approval from Renji Hospital's IRB.

Conditions

Ulcerative Colitis (UC)

Keywords

Ulcerative Colitis; IBD

Outcome Measures

Primary Outcomes (1)

• Percentage of participants achieving endoscopic improvement at Week 12

  Week 12

Secondary Outcomes (6)

• Percentage of participants with adverse events (AEs)

  Baseline, Week 2, 4, 8, 12

• Percentage of participants achieving clinical remission、clinical response

  Week 12

• Percentage of participants achieving symptom remission, symptom response

  Weeks 2, 4, 8, 12

• Pharmacokinetic (PK) characteristics: Plasma concentrations of PTT-621

  Baseline, Weeks 2, 4, 8, 12

• Changes in fecal calprotectin from baseline

  Weeks 2, 4, 8, 12

Study Arms (1)

Participants receiving PTT-621 Dose A

EXPERIMENTAL

Drug: PTT-621 Tablets

Interventions

PTT-621 Tablets DRUG

PTT-621 will be administered orally

Participants receiving PTT-621 Dose A

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \. Male or female participants aged 18-70 years inclusive at screening. 2. Diagnosed with ulcerative colitis (UC) at least 60 days prior to the first dose of IP.
• \. Participants have active UC at screening, defined as a modified Mayo score of 5-9.
• \. Endoscopic evidence of UC extending ≥15 cm from the anal verge during the screening period.
• \. Participants have had inadequate/loss of response or intolerance to at least one of the following: 5-aminosalicylic acid, glucocorticoids, immunosuppressants, biologics, and/or small-molecule targeted therapies.
• \. Participants currently receiving the following UC therapies are eligible if they meet stability requirements: Oral glucocorticoids: with stable dosing for ≥2 weeks prior to screening endoscopy；Oral 5-ASA: Stable dose for at least 2 weeks prior to the endoscopic assessment during the screening period.
• \. Female participants of childbearing potential must have a negative serum/urine pregnancy test at screening.
• \. Willing to use at least one highly effective contraceptive method during sexual intercourse throughout the study and until 1 month after the last dose of IP.
• \. Willing to refrain from sperm/ova donation throughout the study and until 1 month after the last dose of IP.
• \. Able and willing to provide written informed consent and comply with all protocol-specified procedures and visit schedules.

You may not qualify if:

• \. A current diagnosis of Crohn's disease (CD), indeterminate colitis, infectious colitis, or any other colitis/enteritis that could interfere with efficacy evaluation； 2. Has UC complications (e.g., fulminant colitis, toxic megacolon, prior total or partial colectomy, or other conditions requiring surgery)； 3. Prior or current gastrointestinal dysplasia； 4. History of gastrointestinal malignancy, or any current evidence of gastrointestinal cancer.

Sponsors & Collaborators

• Pyrotech Therapeutics, Inc.: lead

Study Sites (1)

Renji Hospital-Shanghai Jiao Tong University School of Medicine

Shanghai, Shanghai Municipality, 200127, China

Location

MeSH Terms

Conditions

Colitis, Ulcerative

Condition Hierarchy (Ancestors)

Colitis; Gastroenteritis; Gastrointestinal Diseases; Digestive System Diseases; Inflammatory Bowel Diseases; Colonic Diseases; Intestinal Diseases

Central Study Contacts

Ran Wei

CONTACT

+86 10 81938094; ran.wei@pyrotech.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 27, 2026
• First Posted: August 5, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): June 1, 2028
• Last Updated: August 7, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)