Aminosalicylic Acid Withdrawal Study in Long Standing Inactive Ulcerative Colitis

Study Purpose

The purpose of this study is to determine whether aminosalicylic acid (ASA) can be safely withdrawn in patients with long-standing clinical inactive UC.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years and Over
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - have a confirmed diagnosis of UC according to established clinical, endoscopic and histologic criteria.
  • - in long-standing clinical remission.
  • - written informed consent.

Exclusion Criteria:

  • - allergic to mesalazine.
  • - prior bowel surgery except appendectomy.
  • - hepatic or renal dysfunction.
  • - malignant disease within 5 years.
  • - pregnancy or breast feeding or women of child-bearing age without regular use of contraception.
  • - on anti-tumor necrosis factor therapy.
- terminal illness

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Chinese University of Hong Kong
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Siew Ng, PhD
Principal Investigator Affiliation Chinese University of Hong Kong
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries Hong Kong

The disease, disorder, syndrome, illness, or injury that is being studied.

Colitis, Ulcerative, Aminosalicylic Acid
Additional Details

This is a randomized, double-blind, controlled trial in which patients with long-standing clinically inactive UC receiving ASA for maintenance of remission will be randomized to either continue 5-ASA or to receive an equivalent placebo for 12 months. The primary endpoint is clinical relapse at 12 months.

Arms & Interventions


Active Comparator: Mesalazine

mesalazine 2g od po for 12 months

Placebo Comparator: Placebo oral capsule

placebo 5 capsules od po for 12 months


Drug: - Mesalazine

Patients will be prescribed Asacol 2g daily for 12 months

Drug: - Placebo oral capsule

Patients will be prescribed placebo 5 capsules daily for 12 months

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

International Sites

Prince of Wales Hospital, Hong Kong, Hong Kong




Prince of Wales Hospital

Hong Kong, , 0000

Site Contact

Siew Ng