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

Brief Title

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

Official Title

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study of Mavorixafor in Patients With WHIM Syndrome With Open-Label Extension

Brief Summary

      This study has a double-blind, placebo-controlled Randomized Period and an Open-Label
      extension Period. The primary objective of the Randomized 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 extension Period, if regionally applicable, until
      mavorixafor becomes commercially available, or until the study is terminated by the Sponsor.
    

Study Phase

Phase 3

Study Type

Interventional

Primary Outcome

Randomized Period: Time (in Hours) Above Absolute Neutrophil Count (ANC) Threshold of 500 Cells/Microliter (µL)

Secondary Outcome

 Randomized Period: Area Under the Curve for ANC (AUCANC) Using Trapezoidal Method

Condition

WHIM Syndrome

Intervention

Mavorixafor

Study Arms / Comparison Groups

 Mavorixafor

Description:  Participants (adults and adolescents [12 to 17 years of age weighing >50 kilograms [kg]) will receive mavorixafor 400 milligrams (mg) once daily (QD) orally for 52 weeks in the Randomized Period. Adolescents weighing ≤50 kg will receive mavorixafor 200 mg QD. Participants who complete the Randomized Period or are granted Early Release due to recurrent or significant infections, as adjudicated by a blinded, independent adjudication committee (AC), will be offered the opportunity to enroll in the Open-Label Period and receive treatment with mavorixafor 400 mg once daily orally until commercial availability or study termination by the Sponsor.

Publications

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Status

Drug

Estimated Enrollment

28

Start Date

October 17, 2019

Completion Date

October 2022

Primary Completion Date

September 2021

Eligibility Criteria

        Inclusion Criteria:

          -  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.

        Exclusion Criteria for the Open-Label Period:

          -  Participants who experience any treatment-limiting toxicity (TLT) will be excluded
             from participating in the Open-Label Period.
      

Gender

All

Ages

12 Years - N/A

Accepts Healthy Volunteers

No

Contacts

Chief Medical Officer, 857-529-5779, [email protected]

Location Countries

Australia

Location Countries

Australia

NCT ID

NCT03995108

Organization ID

X4P-001-103

Secondary IDs

2019-001153-10

Responsible Party

Sponsor

Study Sponsor

X4 Pharmaceuticals

Study Sponsor

Chief Medical Officer, Study Director, X4 Pharmaceuticals

Verification Date

May 2021