This is a proof of concept, randomized, open label, 2-arm study of OPRX-106 in subjects with active mild to moderate ulcerative colitis. Eligible subjects will be enrolled and randomized to receive 2 mg or 8 mg of OPRX-106 administered orally, once daily for 8 weeks.

Main Inclusion Criteria:

1. Have had a diagnosis of ulcerative colitis for a minimum of 3 months
2. Have active mild to moderate ulcerative colitis, as defined by a full Mayo score at screening
3. Have adequate cardiac, renal and hepatic functions as determined by the investigator and demonstrated by screening clinical and laboratory evaluations, and physical examination results
4. High level of calprotectin (>100 mg/kg of stool)

Main Exclusion Criteria:

1. Have a history of colonic or rectal surgery other than hemorrhoidal surgery or appendectomy
2. .Positive for active/ latent mycobacterium tuberculosis (TB) infection
3. .Have a history of infection requiring administration of any IV antibiotic, antiviral or antifungal medication or any oral anti-infective agent
4. Severe ulcerative colitis
5. Ulcerative proctitis, defined as disease limited to less than 15 cm from the anal verge
6. Use >4.8 g 5-ASA or equivalent
7. Use of corticosteroid or 5-ASA enemas, foams, or suppositories
8. Use of anti-inflammatory medications or natural remedies
9. Use oral or parenteral antibiotics
10. Use of chronic non-steroidal anti-inflammatory (NSAID) therapy
11. Use of immune suppressive agents including anti-TNF agents, Azathioprine, 6MP, Methotrexate
12. Use of steroids
13. Have a diagnosis of: Crohn's disease; Indeterminate colitis; Microscopic colitis; Ischemic or infectious colitis; Clostridium difficile colitis, Parasitic disease