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A Study of Mavorixafor in Participants With Severe Congenital Neutropenia and Chronic Idiopathic Neutropenia Disorders

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT04154488
Recruitment Status : Recruiting
First Posted : November 6, 2019
Last Update Posted : May 25, 2022
Information provided by (Responsible Party):
X4 Pharmaceuticals

Brief Summary:
The main goal of this Phase 1b study is to help researchers learn more about how the investigational medicine, mavorixafor, impacts people living with chronic neutropenia (including congenital, idiopathic, and cyclic). Participants of this study will receive one dose of mavorixafor in oral capsules and be monitored for 8 hours to see if neutrophil cell counts increase. Study visits can be conducted at-home or at one of many study clinic locations, depending on the participant's preference. Participants will continue to be monitored for 30 days after single-dose with virtual check-ups.

Condition or disease Intervention/treatment Phase
Neutropenia Drug: Mavorixafor Phase 1

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 25 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase 1B, Open-Label, Multicenter Study of Mavorixafor in Patients With Severe Congenital Neutropenia and Chronic Neutropenia Disorders
Actual Study Start Date : October 16, 2020
Estimated Primary Completion Date : June 30, 2022
Estimated Study Completion Date : July 31, 2022

Arm Intervention/treatment
Experimental: Mavorixafor
Adult participants and adolescent participants who weigh more than 50 kilograms (kg) will receive mavorixafor 400 milligrams (mg) (4 capsules of 100 mg each), orally once on Day 1. Adolescents weighing less than or equal to 50 kg will receive mavorixafor 200 mg (2 capsules of 100 mg each), orally once on Day 1.
Drug: Mavorixafor
Mavorixafor capsules will be administered per dose and schedule specified in the arm.
Other Name: X4P-001

Primary Outcome Measures :
  1. Number of Participants With Treatment-Emergent Adverse Events (TEAEs) [ Time Frame: Baseline up to Follow-up period (Day 36) ]

Secondary Outcome Measures :
  1. Change From Baseline in Absolute Neutrophil Count to 8 hours Post-dose On Day 1 [ Time Frame: Baseline, 60 minutes (± 5 minutes) and 2, 3, 4, 6 and 8 hours (each ± 15 minutes) post-dose on Day 1 ]
  2. Correlation of Serum Concentration of Mavorixafor in Relation to ANC and Area Under The Curve for ANC (AUCANC) [ Time Frame: 0 (pre-dose, up to 15 minutes prior), 60 minutes (each ± 5 minutes) and 2, 3, 4, 6 and 8 hours (each ± 15 minutes) post-dose on Day 1 ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   12 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Key Inclusion Criteria:

  • For all participants:

    • Sign the informed consent form (ICF) and be willing and able to comply with the protocol.
    • Weigh ≥15 kg
    • Agree to use a highly effective form of contraception.
    • Participants may be eligible for the study whether they are on or off G-CSF treatment.

      1. Participants who are on granulocyte-colony stimulating factor (G-CSF) must be on a stable dose for at least 14 days prior to enrollment and for the duration of the study.
      2. Participants who are not on G-CSF must be off for at least 14 days prior to enrollment and for the duration of the study.
    • Have an absolute neutrophil count (ANC) < 1000 cells/µL at the screening and baseline visits. Participants on G-CSF are allowed if their screening and baseline ANC is ≥1000 cells/microliter (uL). Participants with cyclical neutropenia are required to have ANC <1000 cells/ µL only at the baseline visit.
    • Have been diagnosed with chronic neutropenia for at least 6 months prior to screening that is not attributable to medications, active or recent (within 3 months) infections, or malignant cause.

Key Exclusion Criteria:

  • Known systemic hypersensitivity to the mavorixafor drug substance or its inactive ingredients.
  • Is pregnant or nursing.
  • Known history of a positive serology or viral load for human immunodeficiency virus (HIV) or a known history of acquired immune deficiency syndrome.
  • At screening, has laboratory test results meeting one or more of the following criteria:

    • Positive hepatitis C virus (HCV) antibodies with confirmation by HCV-ribonucleic acid polymerase chain reaction reflex testing.
    • Positive hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb).

Note: If a participant tests negative for HBsAg but positive for HBcAb, the participant would be considered eligible if the participant tests positive for antibody to HBsAg reflex testing.

  • At screening, has laboratory test results meeting one or more of the following criteria:

    • Hemoglobin <9.0 grams/deciliter (g/dL).
    • Platelet count <30,000/μL with prior or current history of clinical bleeding events or malignancy or other bone marrow pathologies (e.g., myelodysplastic syndrome).
    • Mild/moderate renal impairment, defined as 30 to 60 milliliter/minute (mL/min) estimated glomerular filtration rate.
    • Serum aspartate transaminase >2.5 * upper limit of normal (ULN).
    • Serum alanine transaminase >2.5 * ULN.
    • Total bilirubin >1.5 * ULN (unless due to Gilbert's syndrome, in which case total bilirubin greater than or equal to (≥) 3.0 * ULN and direct bilirubin >1.5 * ULN).
  • Within 2 weeks before Day 1, received any of the following treatments:

    • Glucocorticoids (>5 mg prednisone equivalent per day).
    • Medication prohibited based on cytochrome P450 (CYP) and/or transporter-based (such as, P-glycoprotein ([P-gp]) potential for drug-drug interaction.
  • At the planned initiation of study drug, has an infection requiring use of antibiotics (systemic or inhaled) or took systemic antibiotics within 4 weeks before Day 1.
  • Has any other medical or personal condition that, in the opinion of the Investigator, may potentially compromise the safety or compliance of the participant, or may preclude the participant's successful completion of the clinical study.
  • Inability to ingest capsules of study drug as presented.
  • Has a history of hematologic malignancy.
  • Diagnosed or have suspected congenital long QT syndrome. Any history of clinically significant ventricular arrhythmias (such as ventricular tachycardia, ventricular fibrillation, or torsades de pointes); any history of arrhythmia will be discussed with the sponsor's medical monitor before participant's entry into the study.
  • Prolonged corrected QT interval using Fridericia's formula on pre-entry electrocardiogram (ECG) (>450 milliseconds [ms]).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04154488

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Contact: Patient Affairs and Advocacy 857-529-5779 clinicaltrialinfo@x4pharma.com

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United States, California
Parexel International Recruiting
Glendale, California, United States, 91206
Contact: Hakop Gevorkyan         
United States, Florida
USF Health Department of Pediatrics Recruiting
Saint Petersburg, Florida, United States, 33701
Contact: Jolan Walter         
United States, Iowa
University of Iowa Hospital and Clinics Recruiting
Iowa City, Iowa, United States, 52242
Contact: Anjali Sharathkumar         
United States, Maryland
Harbor Hospital Recruiting
Baltimore, Maryland, United States, 21225
Contact: Ronald Goldwater         
United States, Michigan
University of Michigan Recruiting
Ann Arbor, Michigan, United States, 48109
Contact: Kelly Jo Walkovich         
United States, Missouri
Washington University School of Medicine Recruiting
Saint Louis, Missouri, United States, 63110
Contact: David Wilson         
United States, New York
Northwell Feinstein Institutes for Medical Research Not yet recruiting
Manhasset, New York, United States, 11030
Contact: Adrianna Vlachos         
United States, Ohio
Cleveland Clinic Not yet recruiting
Cleveland, Ohio, United States, 44195
Contact: Seth Corey         
United States, Texas
University of Texas, Southwestern Not yet recruiting
Dallas, Texas, United States, 75235
Contact: Kathryn Dickerson         
United States, Washington
University of Washington Recruiting
Seattle, Washington, United States, 98195
Contact: David C. Dale         
Sponsors and Collaborators
X4 Pharmaceuticals
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Responsible Party: X4 Pharmaceuticals
ClinicalTrials.gov Identifier: NCT04154488    
Other Study ID Numbers: X4P-001-104
First Posted: November 6, 2019    Key Record Dates
Last Update Posted: May 25, 2022
Last Verified: May 2022

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by X4 Pharmaceuticals:
Chronic congenital neutropenia
Chronic idiopathic neutropenia
Neutropenia glycogen storage disease type 1b
Additional relevant MeSH terms:
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Leukocyte Disorders
Hematologic Diseases