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

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)

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

Study Overview

• Status: Completed
• Conditions: Eosinophilic Gastritis; Eosinophilic Gastroenteritis; Eosinophilic Duodenitis
• Intervention / Treatment: Drug: AK002

• Study Type: Interventional
• Enrollment (Actual): 58
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85021
      • Phoenician Centers for Research and Innovation
    • Scottsdale, Arizona, United States, 85259
      • Mayo Clinic Arizona
  • California
    • Ventura, California, United States, 93003
      • Ventura Clinical Trials
  • Florida
    • New Port Richey, Florida, United States, 34653
      • Advanced Research Institute
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern
  • Iowa
    • Iowa City, Iowa, United States, 52242
      • University of Iowa
  • Maryland
    • Bethesda, Maryland, United States, 20892
      • NIH
  • Massachusetts
    • Boston, Massachusetts, United States, 02111
      • Tufts Medical Center
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • New York
    • New York, New York, United States, 10029
      • Mount Sinai
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina - Chapel Hill
  • Ohio
    • Cincinnati, Ohio, United States, 45229
      • Cincinnati Children's Hospital
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania
  • Tennessee
    • Chattanooga, Tennessee, United States, 37421
      • ClinSearch
    • Nashville, Tennessee, United States, 37212
      • Vanderbilt University
  • Texas
    • Austin, Texas, United States, 78704
      • Avant Research Associates
  • Utah
    • Salt Lake City, Utah, United States, 84132
      • University of Utah

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Provide written informed consent.
2. Completed Study AK002-003, defined as having received 4 infusions of study drug and followed through Day 113 (±3 days) in Study AK002-003 or discontinued from treatment due to high eosinophil counts prior to infusions 2, 3, or 4 and willing to begin extended dosing on or about Day 113 (for AK002-003 completers) or within 6 months of last dosing for patients discontinued from treatment.
3. If patient is on pre-existing dietary restrictions, willingness to note any changes that occur from the Baseline diet, throughout the study.
4. Able and willing to comply with all study procedures.
5. 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.
6. 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:

1. Poor tolerance to previous administration of AK002 in the opinion of the Investigator.
2. Known hypersensitivity to any constituent of the study drug.
3. Any disease, condition (medical or surgical), or cardiac abnormality, which, in the opinion of the Investigator, would place the patient at increased risk.
4. Vaccination with live attenuated vaccines within 30 days prior to initiation of treatment in the study, during the treatment period, or vaccination expected within 5 half-lives (4 months) of study drug administration. All types and formulations of vaccines (including live attenuated vaccines) authorized by FDA or other regulatory authority for the prevention of COVID-19 may be administered before, during, or after this study. The vaccine should not be administered within 7 days prior to and within 7 days after the administration of AK002 so that any side effects caused by either of the 2 medications can be more easily determined.
5. Women who are pregnant, breastfeeding, or planning to become pregnant while participating in the study.
6. Any other reason that, in the opinion of the Investigator or Medical Monitor, makes the patient unsuitable for enrollment.
7. Diagnosis of Hypereosinophilic Syndrome (HES), based on standard criteria (blood eosinophils >1500/µL with involvement of either the heart, nervous system, and/or bone marrow).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1 to 3.0 mg/kg of AK002; 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; AK002 is a humanized non-fucosylated immunoglobulin G1 (IgG1) monoclonal antibody directed against Siglec-8.

What is the study measuring?

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	Adverse events assessed using the CTCAE version 4.03	Through study completion, up to 28 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Change in PRO Total Symptom Score (TSS) From AK002-003 Baseline	The PRO Total Symptom Score (TSS) is a patient-reported outcome (PRO) questionnaire comprises the following 8 symptoms: abdominal pain, nausea, vomiting, early satiety, loss of appetite, abdominal cramping, bloating, and diarrhea. Individual symptom scores ranged from 0 to 10. The daily total symptom score ranged from 0 to 80, with higher scores indicating greater severity. The End of treatment TSS score is defined as the average of the 14 daily scores on or after the day of the last dose of the extension study.	AK002-003 Baseline to End of Treatment (2 weeks post last dose, up to 26 months)
Changes in the Number of Eosinophils in Gastric and/or Duodenal Mucosa From AK002-003 Baseline	Percentage of Change in the Number of Eosinophils in Gastric and/or Duodenal Mucosa in each group from AK002-003 Baseline	AK002-003 Baseline to Day 547

Collaborators and Investigators

• Sponsor: Allakos Inc.
• Investigators: Study Director: Craig Paterson, MD, Allakos Inc.

Study record dates

Study Major Dates

• Study Start (Actual): November 14, 2018
• Primary Completion (Actual): November 2, 2021
• Study Completion (Actual): November 2, 2021

Study Registration Dates

• First Submitted: September 6, 2018
• First Submitted That Met QC Criteria: September 7, 2018
• First Posted (Actual): September 11, 2018

Study Record Updates

• Last Update Posted (Estimated): February 28, 2024
• Last Update Submitted That Met QC Criteria: February 5, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: Eosinophilic Gastritis; Eosinophilic Gastroenteritis; Eosinophil; EG; EGE; Eosinophilic gastrointestinal disorders; EGID; EoD; Eosinophilic Duodenitis
• Additional Relevant MeSH Terms: Digestive System Diseases; Immune System Diseases; Hypersensitivity, Immediate; Hematologic Diseases; Gastrointestinal Diseases; Stomach Diseases; Intestinal Diseases; Hypersensitivity; Esophageal Diseases; Esophagitis; Duodenal Diseases; Leukocyte Disorders; Gastritis; Gastroenteritis; Eosinophilic Esophagitis; Enteritis; Eosinophilia; Duodenitis
• Other Study ID Numbers: AK002-003X

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No