Active — Not RecruitingPhase 3

Efficacy and Safety Study of Mavorixafor in Participants With Warts, Hypogammaglobulinemia, Infections, and Myelokathexis (WHIM) Syndrome

United States, Australia, Austria31 participantsStarted 2019-10-24

Plain-language summary

This study has a double-blind, Randomized Placebo-Controlled Period and an Open-Label Period. The primary objective of the Randomized Placebo-Controlled Period is to demonstrate the efficacy of mavorixafor in participants with WHIM syndrome as assessed by increasing levels of circulating neutrophils compared with placebo, and relative to a clinically meaningful threshold. The primary objective of the Open-Label Period is to evaluate the safety and tolerability of mavorixafor in participants with WHIM syndrome. Participants are allowed to continue treatment in the Open-Label Period, if regionally applicable, until mavorixafor becomes commercially available, or until the study is terminated by the Sponsor.

Who can participate

Age range

12 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria for the Randomized Placebo-Controlled Period : * Have signed the current approved informed consent form. Participants under 18 years of age (in the Netherlands and other applicable regions, participants under 16 years of age) will sign an approved informed assent form and must also have a signed parental/legal guardian consent. * Have a genotype-confirmed mutation of chemokine (C-X-C motif) receptor 4 (CXCR4) consistent with WHIM phenotype. * Agree to use a highly effective form of contraception. * Be willing and able to comply with the protocol. * Have confirmed ANC ≤400 cells/µL during screening, obtained while participant has no clinical evidence of infection. Inclusion Criteria for the Open-Label Period: * Completed the Randomized Period; or * Granted Early Release from the Randomized Period. Exclusion Criteria: * Has known systemic hypersensitivity to the mavorixafor drug substance, its inactive ingredients, or the placebo. * Is pregnant or breastfeeding. * Has any medical or personal condition, which 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.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Randomized Placebo-Controlled Period: Time (in Hours) Above Threshold-Absolute Neutrophil Count (TAT-ANC in hours) of ≥ 500 Cells/Microliter (µL) over a 24-hour period

Timeframe: Time 0 (pre-dose, up to 15 minutes prior), 30, 60, and 90 min (each ± 5 min) and 2, 3, 4, 8, 12, 16, and 24 hours (each ± 15 min) post-dose at Baseline, Weeks 13, 26, 39, and 52

Open-Label Period: Percentage of Participants With Adverse Events (AEs)

Timeframe: From Day 1 (end of randomized period) up to end of study (30 days post-treatment in open-label period [Week 56 of open-label period])

Trial details

NCT IDNCT03995108

SponsorX4 Pharmaceuticals

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-12

View on ClinicalTrials.gov More WHIM Syndrome trials