Phase IIa Study Evaluating AZD7798 in Crohn's Disease

Inclusion Criteria:

1. 18 to 80 years of age.

2. Diagnosis of Crohn's disease established with verifiable clinical, AND at least oneof imaging, endoscopic and/or histopathologic evidence.

3. Moderate to severe active Crohn's disease.

4. Ileal/ileocecal (L1), colonic (L2), or ileocolonic (L3) disease, as classified basedon the localisation of active inflammation.

5. Capable of giving signed informed consent.

6. A history of at least one of:

7. Intolerance or inadequate response to conventional treatment (oralcorticosteroid, azathioprine, 6-mercaptopurine, or methotrexate), biologics, orother approved advanced therapy (eg, JAK inhibitors) OR

8. Corticosteroid dependency (defined as inability to taper below budesonide 6mg/day or prednisolone 10 mg/day equivalent dosing without recurrent activedisease) for the treatment of Crohn's disease.

Exclusion Criteria:

1. Evidence, or clinical suspicion, of other forms of IBD or concomitant additionalactive gastrointestinal luminal inflammatory diseases.

2. Known symptomatic strictures or bowel stenoses or strictures preventing passage ofendoscope throughout the colon.

3. Any complications of Crohn's disease where surgery is anticipated or planned priorto end of study treatment.

4. Evidence of extensive prior gastrointestinal surgical interventions.

5. Within 3 months prior to screening endoscopy visit:

6. History of toxic megacolon

7. Diagnosis of peritonitis or need for treatment of peritonitis

8. Bowel perforation or evidence of obstruction.

9. All intrabdominal abscesses are excluded. Cutaneous and perianal/perirectalabscesses and fistulae are excluded unless adequately drained at least 4 weeks priorto screening endoscopy visit with no anticipation for surgery prior to end of studytreatment.

10. Ongoing or expected nutritional dependency on total enteral or parenteral nutritionduring study.

11. Evidence of an increased risk of colorectal cancer.

12. Symptomatic oral Crohn's disease within one year.

13. Any of the following treatments within the specified time period prior to screeningendoscopy visit

14. An anti-TNF biologic within 8 weeks prior to screening endoscopy visit

15. Any biologic targeting immune response other than an anti-TNF within 12 weeksprior to screening endoscopy visit

16. Other advanced small molecule treatments for Crohn's disease within 4 weeksprior to screening endoscopy visit

17. Cyclosporine, mycophenolate mofetil, sirolimus (rapamycin), thalidomide, ortacrolimus (FK-506) within 4 weeks prior to screening endoscopy visit

18. Treatment with apheresis within 4 weeks prior to screening endoscopy visit

19. Administration of any live vaccine within 4 weeks prior to screening endoscopyvisit to end of study

20. Faecal microbiota transplantation within 4 weeks prior to screening endoscopyvisit

21. Lymphocyte-depleting treatment within 12 months prior to screening endoscopyvisit

22. Any previous exposure to AZD7798.

23. Any changes in dosing of the following medications prior to screening endoscopyvisit as outlined:

24. 5-aminosalicylates within 2 weeks

25. Oral corticosteroids within 2 weeks or stable doses of steroids exceeding thefollowing dose equivalents:

(i) Systemic steroids > 20 mg/day or prednisolone equivalent (ii) Locally targetedsteroids exceeding maximum budesonide dose equivalent (9 mg/day) (c)Immunomodulators within 4 weeks (d) Antibiotic therapy for the treatment of Crohn'sdisease (e) Probiotics within 2 weeks.

12. Known or suspected history of chronic use of nonsteroidal anti-inflammatory drugs.

13. Evidence of recent or currently active infection, including use of IV or oralantibiotics for documented infection within 30 days prior to screening endoscopyvisit.

14. Evidence of chronic HBV or HCV.

15. History of TB (active or latent) unless an appropriate course of treatment has beencompleted.

16. Positive diagnostic TB test at screening.

17. History of serious opportunistic infection within 12 months prior to screeningendoscopy visit.

18. CMV colitis within previous 12 months prior to screening endoscopy visit.

19. Positive C. difficile toxin stool test at screening.

20. Symptomatic herpes zoster infection within 3 months prior to screening endoscopy.

21. Any identified immunodeficiency.

22. Abnormal laboratory results at screening suggesting participation may be unsafe,which will prevent the patient from completing the study, or will interfere with theinterpretation of the study results.

23. Reproduction:

24. Pregnant and breastfeeding patients, or those planning to breastfeed during thestudy

25. FOCBP unless completely abstinent or using a highly effective contraception andbarrier method of contraception.

26. Prolonged QTcF interval.

27. Clinically significant cardiovascular conditions.

28. Current malignancy or history of malignancy.

29. Current significant major or unstable respiratory disease, heart disease,cerebrovascular disease, haematological disease, hepatic disease, renal disease,gastrointestinal disease or other major disease other than active Crohn's disease.

30. Current enrolment in another interventional study or treatment with anyinvestigational drug within 4 months prior to screening endoscopy visit.

31. Unstable lifestyle factors.

32. Patients committed to an institution by virtue of an order issued either by thejudicial or the administrative authorities.

33. Investigator concerns regarding patient's willingness and ability to attend allstudy visits, comply with the study procedures, read in order to completequestionnaires, or to complete the study period