Safety and Efficacy of MMX Mesalamine/Mesalazine in Pediatric Subjects With Mild to Moderate Ulcerative Colitis

Inclusion Criteria:

1. Ability to voluntarily provide written, signed, and dated (personally or via a legally
authorized representative [LAR]) informed consent or assent as applicable to
participate in the study.

2. Subject's parent/LAR demonstrates an understanding, ability, and willingness to fully
comply with study procedures and restrictions.

3. Male and female children and adolescents aged 5-17 years, inclusive.

4. Body weight 18-90kg.

5. Male, or non-pregnant, non-lactating female who agrees to comply with any applicable
contraceptive requirements of the protocol or females of non-childbearing potential.

6. Diagnosed with mild to moderate UC, established by sigmoidoscopy or colonoscopy with
compatible histology. Screened subjects may also have an unconfirmed diagnosis of mild
to moderate UC; however the diagnosis of mild to moderate UC must have been
established by sigmoidoscopy or colonoscopy with compatible histology prior to
baseline visit.

7. Subject is able to swallow the investigational product whole.

Double-blind Acute Phase:

8. Partial UC-DAI score ≥2 (a combined rectal bleeding and stool frequency score ≥1 and
PGA=1 or 2) at the Baseline Visit, for which 5-ASA would be used as part of normal
treatment.

9. If the subject is on 5-ASA treatment prior to study entry, then the dose must be
stable. Stable therapy is defined as no change in dose, or no initiation of 5-ASA,
from the onset of the current acute flare through discontinuation of therapy (required
at the Baseline Visit).

Double-blind Maintenance Phase:

10. Partial UC-DAI ≤1 (rectal bleeding=0, stool frequency ≤1, and PGA=0) at the Baseline
Visit.

Exclusion Criteria:

1. Severe UC (defined by PGA=3).

2. Crohn's disease, bleeding disorders, active peptic ulcer disease, or UC known to be
confined to the rectum (isolated rectal proctitis).

3. Asthma, only if known to be 5 ASA sensitive.

4. Positive stool culture for enteric pathogens (including Salmonella, Shigella,
Yersinia, Aeromonas, Plesiomonas, or Campylobacter). Clostridium difficile toxin, ova,
or parasites present.

5. Systemic or rectal corticosteroid use within 4 weeks prior to the Screening Visit.
Topical, intranasal, or inhaled use is not exclusionary.

6. Immunomodulator (6-mercaptopurine, azathioprine) use within 6 weeks prior to the
Screening Visit.

7. History of biologic (eg, anti-tumor necrosis factor agents, integrin receptor
antagonists) use at any time.

8. Antibiotic use within 7 days prior to the Screening Visit.

9. Any anti-inflammatory drugs, not including 5-ASA treatment but including non-steroidal
anti-inflammatory drugs such as aspirin, COX-2 inhibitors or ibuprofen, within 7 days
prior to the Screening Visit unless used at over-the-counter levels for <3 days.
However, prophylactic use of a stable dose of aspirin up to 325mg/day for cardiac
disease is permitted.

10. Prebiotic/probiotic use within 7 days prior to the Screening Visit. Yogurt products
are permitted.