An Extension Study of AK002 in Patients With Eosinophilic Gastritis and/or Eosinophilic Duodenitis

Study Overview
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Brief Summary
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This is a Phase 2, open-label, extension study to assess the safety and tolerability of AK002, given monthly for up to 26 doses.

Official Title
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A Phase 2, Multicenter, Open-Label, Extension Study to Evaluate the Safety and Tolerability of AK002 in Patients With Eosinophilic Gastritis and/or Eosinophilic Duodenitis (Formerly Referred to as Eosinophilic Gastroenteritis)

Conditions
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Eosinophilic Gastritis, Eosinophilic Gastroenteritis, Eosinophilic Duodenitis

Intervention / Treatment
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* Drug: AK002


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Provide written informed consent. Completed Study AK002-003, defined as having received 4 infusions of study drug and followed through Day 113 (±3 days) in Study AK002-003 and willing to begin extended dosing on or about Day 113. Able and willing to comply with all study procedures. Female patients must be either post-menopausal for at least 1 year or surgically sterile (tubal ligation, hysterectomy, or bilateral oophorectomy) for at least 3 months, or if of childbearing potential, have a negative pregnancy test and agree to use dual methods of contraception, or abstain from sexual activity until the end of the study, or for 120 days following the last dose of study drug, whichever is longer. Male patients with female partners of childbearing potential must agree to use a highly effective method of contraception until the end of the study or for 120 days following the last dose of study drug, whichever is longer. All fertile men with female partners of childbearing potential should be instructed to contact the Investigator immediately if they suspect their partner might be pregnant at any time during study participation. Exclusion Criteria: Poor tolerance to previous administration of AK002 in the opinion of the Investigator. Known hypersensitivity to any constituent of the study drug. Any disease, condition (medical or surgical), or cardiac abnormality, which, in the opinion of the Investigator, would place the patient at increased risk. Planned or expected vaccination with live attenuated vaccines during the treatment, or vaccination expected within 5 half-lives (4 months) of AK002 administration. Women who are pregnant, breastfeeding, or planning to become pregnant while participating in the study. Any other reason that, in the opinion of the Investigator or Medical Monitor, makes the patient unsuitable for enrollment.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1 to 3.0 mg/kg of AK002<br>Subjects in this arm will receive 26 monthly doses of AK002: a first dose of 1 mg/kg, followed by monthly doses of 3 mg/kg | Drug: AK002<br>* AK002 is a humanized non-fucosylated immunoglobulin G1 (IgG1) monoclonal antibody directed against Siglec-8.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The safety and tolerability of AK002 by evaluating adverse events assessed using the CTCAE version 4.03 |  | Day 785 (End of Study) | 
| The safety and tolerability of AK002 as assessed by symptom-directed physical examination of reported or observed patient symptoms warranting examination, including assessments of possible infusion site reactions and infusion-related reactions |  | Day 1 to Day 785 (End of Study) | 
| Evaluation of symptoms of EG and/or EoD (formerly referred to as EGE) using a daily disease-specific patient questionnaire (PRO Questionnaire) |  | Baseline to Day 785 (End of Study) | 
| Changes in the number of eosinophils in gastric and/or duodenal mucosa |  | Baseline to Day 729 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Eosinophilic Gastritis, Eosinophilic Gastroenteritis, Eosinophil, EG, EGE, EGID, Eosinophilic gastrointestinal disorders, Eosinophilic Duodenitis, EoD