Efficacy and Safety of BBT-401-1S in Ulcerative Colitis

Inclusion Criteria:

- Provision of signed and dated informed consent form (ICF)

- Stated willingness to comply with all study procedures and availability for the
duration of the study

- Male or female, aged >=18 years

- Diagnosed with active UC for at least 3 months prior to screening

- Total Mayo score >=5 and Endoscopic sub-score >=1

- Stable dosing regimens of oral drugs (if currently administered) as follows: 5-ASA or
sulfasalazine at a stable dose for at least 4 weeks, purine analogues (azathioprine,
mercaptopurine, thiopurines) or methotrexate at a stable dose for at least 12 weeks,
and low-dose oral corticosteroid (up to 20 mg prednisone/day or equivalent) for at
least 4 weeks prior to the first dose of study treatment. Doses of oral drugs must
remain stable until the end of study treatment (with possible exception for tapering
steroid dose after 8 weeks)

- For females of reproductive potential: use of highly effective contraception for at
least 1 month prior to screening and agreement to use such a method during study
participation and for an additional 3 months after the last dose

- For males of reproductive potential: use of condoms or other methods to ensure
effective contraception with partner during study participation and for an additional
3 months after the last dose

Exclusion Criteria:

- Use of anti-TNF-a biologics or any other biologics for treatment of UC within 60 days
prior to randomization.

- Any rectal therapy for treatment of UC or intravenous corticosteroids within 2 weeks
prior to randomization.

- Presence of Crohn's disease, indeterminate colitis, ischemic colitis, fulminant
colitis, ulcerative proctitis, or toxic mega-colon

- Previous extensive colonic resection (subtotal or total colectomy)

- Ileostomy, colostomy, or known fixed symptomatic stenosis of the intestine

- Evidence of or treatment for Clostridium difficile infection or other pathogenic bowel
infection within 60 days or for another intestinal pathogen within 30 days prior to
randomization

- Active infection with the HIV or Hepatitis B or C viruses

- Clinically significant active extra-intestinal infection (e.g., pneumonia,
pyelonephritis)

- Clinically significant abnormal vital signs, physical examination or 12-lead
electrocardiogram (ECG) at screening or baseline

- Clinically significant abnormal results of liver function tests (ALT/AST, bilirubin
and alkaline phosphatase) > 2X the upper limit of normal (ULN) at screening

- Other clinically significant abnormal laboratory results at screening in the
investigator's opinion

- History of any clinically significant medical condition that, in the investigator's
opinion, would preclude participation in the study

- Pregnancy or lactation

- Treatment with another investigational drug or other intervention within 30 days prior
to screening