CTRI/2019/04/018626.

Methods	Study design: randomised, parallel group trial Settings: 32 hospitals in India Study period: 15 May 2019 to present (estimated duration 2 years)
Participants	Inclusion criteria: adults age 18–65 years; mild‐to‐moderate active UC involving whole of colon of left side (around 60 cm from the anal verge); DAI score 4–10; baseline rectal bleeding score ≥ 1; baseline mucosal appearance score ≥ 1; baseline stool frequency score ≥ 1; failed to achieve remission on topical or oral (or both) standard treatment regimen of mesalamine over minimum 4 weeks of duration; childbearing age females must have a negative serum pregnancy test at screening and negative urine pregnancy test at enrolment; both men and women must agree to use appropriate form of contraceptives themselves and their partners; able to understand and sign an informed consent form; acceptable biochemical markers Exclusion criteria: proximal UC, Crohn's pancolitis; DAI score 3 or ≥ 11; with signs and symptoms of fulminant colitis, bowel stricture, toxic megacolon, an anticipated need for blood transfusion for gastrointestinal bleeding or demonstrate evidence of peritonitis; high‐grade dysplasia on biopsy; known allergy to the study medications; enteric pathogens on stool culture; steroids or immunosuppressants < 4 weeks prior to screening; antibiotic, antifungal or antiparasitic < 1 week prior to screening; history of cancer; hyperkalaemia; positive pregnancy test; history of substance abuse, HIV, hepatitis B and C; receiving potassium‐sparing diuretics, pre‐existant renal failure, hypertension, liver disorders, pulmonary disease, psychiatric and metabolic disorders; participation in any clinical study < 30 days prior to screening; or other major health conditions. 303 participants Disease activity: NR Disease duration: NR Extent of disease: NR Age: NR Sex (M/F): NR Concurrent therapies: NR Number enrolled: NR Number randomised: NR Number reaching end of study: NR
Interventions	IG: tacrolimus CG: hydrocortisone
Outcomes	Primary outcome: evaluation of the efficacy of tacrolimus lipid suspension for enema against (hydrocortisone retention enema) in adults with mild‐to‐moderately active UC refractory to mesalamine treatment Duration: 4 weeks Secondary outcomes: Evaluation of the safety of the participants exposed to the study drugs Estimation of the blood level of tacrolimus following its local administration in participants randomised in test arm Duration: throughout the study Length of intervention and follow‐up points: NR Definition of remission or clinical improvement by study authors: NR Number of participants who achieved remission: NR Number of participants who achieved clinical improvement: NR Time to onset of action for tacrolimus from beginning of study: NR Number of participants who required other rescue medication: NR Time to other rescue medication from beginning of study: NR Number of participants who underwent surgery: NR Time to surgery from beginning of study: NR Adverse events: NR Withdrawal due to adverse events: NR Serious adverse events: NR Time to adverse events from beginning of study: NR
Notes	Contacted authors by email on 23 November 2020 to request further details (prashantmodi@lambda‐cro.com). Received response on 24 November 2020 stating that the trial is under confidentiality agreement with the sponsor, hence details of the methods and results cannot be shared.