Children aged up to 18 years with moderately active Ulcerative Colitis (PUCAI:35-64) will receive one weekly Adacolumn® apheresis treatment over 5 consecutive weeks, followed by up to 3 optional Adacolumn® apheresis treatments over 3 consecutive weeks. Primary end point is PUCAI at Week 12.

The main part of the clinical investigation will be continued by a one year follow up for responders.

The individual clinical investigation period will be 12 weeks per patient. If the patient will take part in the follow up, the individual clinical investigation period will be 64 weeks.

Patients receive one weekly Adacolumn® apheresis over 5 consecutive weeks. The treating investigator may decide to add up to 3 treatments based on his judgment.

Treatment details Day -07: Screening; Day 00 Baseline: 1st Adacolumn® apheresis; Day 07: 2nd Adacolumn® apheresis; Day 14: 3rd Adacolumn® apheresis; Day 21: 4th Adacolumn® apheresis; Day 28: 5th Adacolumn® apheresis; Week 12:Final evaluation

Inclusion Criteria:

1. Children and adolescents < 18 years

2. Ulcerative colitis documented by clinical symptoms, endoscopic findings and histology (in patient history)

3. Moderate active ulcerative colitis at baseline evaluation, defined as follows:PUCAI between 35 and 64

4. Pancolitis or left-sided colitis

5. Ulcerative colitis for at least 3 months

6. Receiving or having received one or more of the following medicinal products before screening:

   • Sulfasalazine, mesalamine and other 5-aminosalicylic acid (5-ASA) agents for 4 weeks or more with a stable dose for the last 2 weeks,
   • 0.5mg/kg/body weight with a maximum of 20 mg per day of prednisone with a stable dose for the last 2 weeks, or
   • 6-mercaptopurine or azathioprine for 12 weeks or more with a stable dose for the last 4 weeks Other UC medication is not allowed (see also Chapter 4.4.2).

7. For female patients of child-bearing potential, a negative pregnancy test and agreement to use an effective contraceptive method or abstain from sexual activities during the course of the clinical investigation

8. Agreement to participate in all visits

9. Signed written informed consent document by patients and their legal guardian or representative

10. Body weight must be more or equal 30kg

11. Adequate peripheral venous access to allow for completion of the apheresis treatments

Exclusion Criteria:

1. Febrile (>38ºC)

2. Evidence of toxic megacolon

3. Anticipated need for surgery within 12 weeks after Day 00

4. Major surgery within the past 6 weeks

5. Known obstructive diseases of the gastrointestinal system

6. Proctocolectomy, total colectomy, ileostomy, stoma or ileal pouch-anal anastomosis

7. A history of allergic reaction to heparin or heparin-induced thrombocytopenia

8. A history of hypersensitivity reaction associated with an apheresis procedure or intolerance of apheresis procedures

9. Known infection with enteric pathogens, pathogenic ova or parasites, or a positive assay for C. difficile toxin

10. Symptomatic hypotension

11. Pediatric heart conditions and problems at high susceptibility for thrombotic events (e.g. valve defects or similar)

12. A history of physical findings compatible with a cerebrovascular accident

13. Prosthetic heart valve, pacemaker or other permanent implant

14. Severe cardiovascular or peripheral vascular disease

15. Liver disease defined as levels of GOT [AST], GPT [ALT] or alkaline phosphatase >2.5x the upper limit of the normal range for the laboratory performing test

16. History of cirrhosis

17. Renal insufficiency, defined as serum creatinine >150% of the upper limit of the normal range for the laboratory performing the test

18. Known bleeding disorder (PT or PTT>1.5x the upper limit of the normal range for the laboratory performing the test), or concomitant anticoagulant therapy for purposes other than apheresis treatment

19. Prior history suggestive of a hypercoagulable disorder, including 1 or more episodes of pulmonary embolism or deep vein thrombosis

20. Known infection with Hepatitis B or C, or HIV

21. Abnormal hematology parameters defined as severe anemia with hemoglobin <8.5g/dL, white blood cell count of <3,500/μl and a granulocyte count <2,000/μl

22. Fibrinogen level >700mg/dL

23. Infection:

    • Active infections from successful completion of antibiotic treatment for routine bacterial infection less than 4 weeks of entry into the clinical investigation (screening)
    • Febrile viral infection within 4 weeks of entry into the clinical investigation (screening)
    • Less than 12 weeks from conclusion of therapy for systemic fungal infections to screening

24. Malignancy within the past 2 years other than surgically cured skin carcinoma or cervical dysplasia (CIN I-II)

25. History of dysplasia or carcinoma of the colon

26. Current drug or alcohol abuse

27. Pregnant, lactating or planning to become pregnant during the course of the clinical investigation

28. Used within the last 30 days an investigational medicinal product, biologic or device

29. Pre-treatment of UC with drugs other than 5-ASA and derivatives, azathioprine and or corticosteroids, e.g. immunosuppressants and biologics

30. Steroid-resistance or -dependency, defined as inability to completely withdraw steroids without inducing a relapse or flare-up of the disease

31. Topical therapy for ulcerative colitis within the last 2 weeks.