ADAPT Study: Long-term Safety Study of INZ-701 in Patients With ENPP1 Deficiency and ABCC6 Deficiency

Phase 2

Recruiting

Conditions: Gene Mutations
Pseudoxanthoma Elasticum
Arterial Calcification
Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency
Autosomal Recessive Hypophosphatemic Rickets Type 2

Brief Summary: The purpose of this study (Study INZ701-304 \[ADAPT\]) is to assess the long-term safety of INZ-701 in patients with ENPP1 Deficiency or ABCC6 Deficiency who have received INZ-701 in an existing clinical study and choose to continue dosing for the potential treatment of their condition.

Detailed Description: The investigational product INZ-701 is being developed as a therapeutic protein for the treatment of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) Deficiency and adenosine triphosphate (ATP)-binding cassette subfamily C member 6 (ABCC6) Deficiency. INZ-701 is a recombinant fusion protein that contains the extracellular domains of human ENPP1 coupled with an Fc fragment from an immunoglobulin (Ig) G1 antibody.

The ADAPT Study (INZ701-304) is an open-label study to assess the long-term safety of INZ-701 in patients with ENPP1 Deficiency or ABCC6 Deficiency who have received INZ-701 in an existing clinical study and choose to continue dosing for the potential treatment of their condition.

The study will consist of a 30-day Screening Period, followed by an open-label Treatment Period during which all participants will receive once-weekly subcutaneous (SC) doses of INZ-701 and continue with treatment until INZ-701 is commercially available in the country/region of the participant's residence or until Inozyme chooses to discontinue development of INZ-701. Participants will complete an End of Study (EOS) safety follow-up visit approximately 30 days after their last designated study visit assigned by the Investigator and/or Sponsor.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
INZ-701	INZ-701	INZ-701 will be administered by subcutaneous injection on a once-weekly basis as follows: * Study participants from 1 year to \<13 years of age will receive a dose of 2.4 mg/kg * Study participants ≥13 years will either receive a 1.8 mg/kg dose or a 150 mg flat dose of INZ-701

Primary Outcome Measures

Name	Time	Method
Incidence of Anti-Drug Antibodies (ADA)	6 years (long term safety assessment)	For each subject, the presence of ADAs will be assessed and, if present, further evaluation will determine specificity and subtypes.
Number of Treatment Emergent Adverse Events (TEAEs)	6 years (long term safety assessment)	Treatment-emergent AEs are defined as any AE occurring from the first dose of INZ-701 through 30 days after the last dose of INZ-701.

Secondary Outcome Measures

Name	Time	Method
Mean Change from Baseline in Plasma PPi Concentration	6 years (long term safety assessment)	For each subject, their plasma PPi concentrations based on a validated assay will be collected and assessed throughout the study, comparing the participant's baseline value over time.
Time to maximum serum concentration (Tmax)	6 years (long term safety assessment)	For each subject, the time to reach maximum concentration of INZ-701 in the plasma will be measured via a series of blood samples obtained throughout the study, comparing the participant's baseline value over time.
Maximum Plasma Concentration (Cmax) of INZ-701	6 years (long term safety assessment)	For each subject, the maximum concentration of INZ-701 in the plasma will be measured via a series of blood samples obtained throughout the study, comparing the participant's baseline value over time.collected and assessed.

Locations (5): Mayo Clinic
🇺🇸
Rochester, Minnesota, United States
Clinilabs Drug Development Corporation
🇺🇸
Eatontown, New Jersey, United States
Necker-Enfants Malades Hospital
🇫🇷
Paris, France
Universitätsklinikum Hamburg-Eppendorf (UKE)
🇩🇪
Hamburg, Germany
VCTC
🇬🇧
Oxford, United Kingdom