24-Week Induction Study of APT-1011 in Adult Subjects With Eosinophilic Esophagitis (EoE) (FLUTE 3)

1. Have known contraindication, hypersensitivity, or intolerance to corticosteroids

2. Have a contraindication to, or factors that substantially increase the risk of, EGD procedure or esophageal biopsy or have narrowing of the esophagus that precludes EGD with a standard (8-10 mm) endoscope

3. Have history of an esophageal stricture requiring dilatation within the 12 weeks prior to Screening

4. Have any physical, mental, or social condition or history of illness or laboratory abnormality that in the Investigator's judgment might interfere with study procedures or the ability of the subject to adhere to and complete the study or increase the safety risk to the subject such as uncontrolled diabetes or hypertension

5. History of recurrent or current oral or esophageal mucosal infection due to inhaled or nasal corticosteroids

6. Have any mouth or dental condition that prevents normal eating (excluding braces)

7. Have any condition affecting the esophageal mucosa or altering esophageal motility other than EoE, including erosive esophagitis (grade B or higher as per the Los Angeles Classification of Gastroesophageal Reflux Disease; hiatus hernia longer than 3 cm, Barrett's esophagus, and achalasia)

8. Use of systemic (oral or parenteral) corticosteroids within 30 days before Screening, use of swallowed corticosteroids within 30 days before Screening

9. Initiation of either inhaled or nasal corticosteroids or high-potency dermal topical corticosteroids within 30 days before Screening

10. Use of calcineurin inhibitors or purine analogues (azathioprine, 6-mercaptopurine) in the 12 weeks before Screening

11. Use of potent cytochrome P450 (CYP) 3A4 inhibitors (e.g., ritonavir and ketoconazole) in the 4 weeks before Screening

12. Initiation of an elimination diet or elemental diet within 30 days before Screening (diet must remain stable after signing ICF)

13. Abnormal ACTH stimulation defined as a serum cortisol level \<16 μg/dL (440 nmol/L) at 60 minutes with ACTH stimulation test using 250 μg cosyntropin

14. Use of biologic immunomodulators, including dupilumab for EoE, with dose last administered within 6 months before Screening (allergy desensitization injection or oral therapies allowed as long as the course of therapy is not altered during the study period)

15. Subjects who have initiated, discontinued, or changed dosage regimen of histamine H2 receptor antagonists, antacids or antihistamines, leukotriene inhibitors, or sodium cromolyn within 4 weeks before qualifying endoscopy during Screening. If already receiving these drugs, the dosage must remain constant throughout the study

16. Subjects who have initiated PPIs within 8 weeks before qualifying endoscopy. If already receiving PPIs, the dosage regimen must remain constant throughout the study

17. Have gastrointestinal bleeding or documented active peptic ulcer within 4 weeks prior to Screening or entering a new study period

18. Have chronic infection such as prior or active tuberculosis, active chicken pox or measles, or absence of prior measles, mumps, and rubella vaccine. Subjects with tuberculosis exposure or who live in, or travel to, high endemic areas should be assessed locally for tuberculosis before consideration for the study

19. Immunosuppression or immunodeficiency disorder

20. Current malignancy or malignancy within 3 years of Screening, with the exception of skin cancers other than melanoma. Subjects in remission for at least 3 years post-treatment may be enrolled.

21. Have a history or presence of Crohn's disease, celiac disease, or other inflammatory disease of the gastrointestinal tract, including non-EoE eosinophilic gastrointestinal disorders (EGIDs)

22. Have current drug abuse in the opinion of the Investigator

23. Have current alcohol abuse in the opinion of the Investigator

24. Female subjects who are pregnant, breastfeeding, or planning to become pregnant during the study

25. Sexually active females of childbearing potential who do not agree to follow highly effective contraceptive methods through the End of Study visit

26. Have received an investigational product as part of a clinical trial within 30 days (or 5 half-lives, whichever is longest) of Screening. Subjects who are currently participating in observational studies or enrolled in patient registries are allowed in this study

27. Have participated in a prior study with investigational product APT-1011

What this study is about