Ectonucleotide Pyrophosphatase/phosphodiesterase1 DeficiencyPhase 3NCT07473973
ENERGY 2: Evaluation of the Efficacy and Safety of INZ-701 in Infants With ENPP1 Deficiency
A Phase 3 study testing INZ-701 in people with Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency and Autosomal Recessive Hypophosphatemic Rickets, run by Inozyme Pharma at 8 sites in 8 countries.
Trial summary
The primary purpose of ENERGY 2 (Study INZ701-105) is to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency. Read more about this study
- Who is it for?
- Ages 0 years to 1 year
- Conditions the study is for
- Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency, Autosomal Recessive Hypophosphatemic Rickets, Generalized Arterial Calcification of Infancy 1
- What is being tested?
- INZ-701
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2 participants
- Where
- 8 sitesin 8 countries
- Study dates
- 26 Mar 2025to 31 Aug 2026
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 0 years to 1 year
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Infant aged ≤ 1 year at the time of enrollment.
- Confirmed diagnosis of ENPP1 deficiency, based on genetic testing.
- Clinical features consistent with generalized arterial calcification of infancy (GACI) (e.g., vascular calcification or cardiac involvement).
- Medically stable to participate in a 52-week treatment study.
- Written informed consent provided by a parent or legal guardian.
Who cannot join
- Participants will not be eligible if any of the following apply:
- Receiving end-of-life or hospice care.
- Prior treatment with INZ-701, unless received through an approved expanded access program.
- Concurrent participation in another interventional clinical trial.
- Planned major surgery during the study period that would interfere with study participation.
Trial locations and contacts
8 sites in 8 countries.
8 sites in 8 countries
Brazil1 site
Hospital Universitario Pedro Ernesto/Rio de Janeiro
Rio de Janeiro, 20551-030
Saudi Arabia1 site
King Faisal Specialist Hospital and Research Center
Riyadh, 12713
Spain1 site
Hospital Sant Joan de Deu Edificio Consultas Externas. Unitat de Recerca
Barcelona, Esplugues de Llobregat, 08950
Turkey (Türkiye)1 site
Umraniye Traiing and Research Hospital
Istanbul
United Kingdom1 site
Royal Manchester Children's Hospital
Manchester, M13 9WL
About this study
Official title: The ENERGY 2 Study: An Open-Label Phase 3 Study to Evaluate the Efficacy and Safety of INZ-701 in Infants With Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) Deficiency
The primary purpose of ENERGY 2 (Study INZ701-105) is to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
Read the detailed description
ENPP1 Deficiency is an ultra-rare genetic disorder in which inactivating mutations in the ENPP1 gene lead to a deficiency in the ENPP1 enzyme.
ENERGY 2 (Study INZ701-105) is a multicenter, single-arm, open-label Phase 3 study to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
The study will consist of a Screening Period of up to 60 days, a Treatment Period of 52 weeks, a 52-week Extension Period, and an End of Treatment (EOT) Visit 30 days after the last dose of INZ-701.
- Conditions
- Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency, Autosomal Recessive Hypophosphatemic Rickets, Generalized Arterial Calcification of Infancy 1
- Being tested
- INZ-701
- Keywords
- Generalized Arterial Calcification of Infancy, GACI, Autosomal Recessive Hypophosphatemic Rickets Type 2, ARHR2
- Medical subject headings
- Hypophosphatemic Rickets, Autosomal Recessive, 1, Arterial calcification of infancy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
INZ-701Drug
Also called (rhENPP1-Fc).
Recombinant fusion protein that contains the extracellular domains of human ENPP1 coupled with an Fc fragment from an immunoglobulin gamma-1 (IgG1) antibody.
| Study group | Role | What they receive |
|---|---|---|
| INZ-701 | Experimental | Participants receive INZ-701 (rhENPP1-Fc) administered by subcutaneous injection once weekly at the protocol-specified dose. The visit final volume to administer (mL) is determined using protocol-defined parameters. Receives: Drug: INZ-701 |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine if INZ-701 increases inorganic pyrophosphate (PPi) levels
For each subject, their change from baseline in Plasma Inorganic Pyrophosphate (PPi) concentration will be assessed.
Measured: 52 weeks (Baseline through Week 52)
To determine if INZ-701 increases overall survival
For each subject, their change in overall survival based on time from date of birth to event of all-cause mortality will be assessed.
Measured: 52 weeks (Baseline through Week 52)
Secondary outcomes (3)
To determine if INZ-701 prevents decline in cardiac ejection fraction
For each subject, their change from baseline in left ventricular ejection fraction will be assessed via echocardiography.
Measured: 52 weeks (Baseline through Week 52)
To determine if INZ-701 prevents heart failure
For each subject, their incidence of heart failure will be assessed.
Measured: 52 weeks (Baseline through Week 52)
To determine if INZ-701 attenuates progression of arterial calcification
For each subject, their change from baseline in vascular calcification in the coronary arteries and aorta will be examined via CT scan.
Measured: 52 weeks (Baseline through Week 52)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Mar 2026
- Study start26 Mar 2025
- Primary completion31 Aug 2026
- Study completion31 Aug 2026
Why it stopped: Following review of the totality of program data, the sponsor decided to discontinue development of INZ701. The decision was not related to safety.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ectonucleotide Pyrophosphatase/phosphodiesterase1 DeficiencyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- ENERGY 2 (Study INZ701-105) is a multicenter, single-arm, open-label Phase 3 study to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
- Masking
- None (open label)
- Enrolment
- 2 participants (actual)
Sponsor and investigators
- Lead sponsor
- Inozyme Pharma
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- BioMarin Pharmaceutical
- Responsible party
- Sponsor
- Investigators
- Medical Director, MD, Study director, BioMarin Pharmaceutical
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07473973
- Sponsor's protocol ID
- INZ701-105
- Status last verified
- Sep 2026
- First submitted
- 11 Mar 2026
- Last updated
- 29 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The ENERGY 2 Study: An Open-Label Phase 3 Study to Evaluate the Efficacy and Safety of INZ-701 in Infants With Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) Deficiency
- ClinicalTrials.gov ID
- NCT07473973
- Acronym / sponsor ID
- INZ701-105
- Conditions
- Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency, Autosomal Recessive Hypophosphatemic Rickets, Generalized Arterial Calcification of Infancy 1
- Keywords
- Generalized Arterial Calcification of Infancy, GACI, Autosomal Recessive Hypophosphatemic Rickets Type 2, ARHR2
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Following review of the totality of program data, the sponsor decided to discontinue development of INZ701. The decision was not related to safety.
- Enrolment
- 2 participants (actual)
- Lead sponsor
- Inozyme PharmaIndustry (pharma, biotech, devices)
- Collaborators
- BioMarin Pharmaceutical
- Study start
- 26 Mar 2025 (actual)
- Primary completion
- 31 Aug 2026 (actual)
- Study completion
- 31 Aug 2026 (actual)
- First posted
- 16 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary purpose of ENERGY 2 (Study INZ701-105) is to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
Detailed description
ENPP1 Deficiency is an ultra-rare genetic disorder in which inactivating mutations in the ENPP1 gene lead to a deficiency in the ENPP1 enzyme.
ENERGY 2 (Study INZ701-105) is a multicenter, single-arm, open-label Phase 3 study to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
The study will consist of a Screening Period of up to 60 days, a Treatment Period of 52 weeks, a 52-week Extension Period, and an End of Treatment (EOT) Visit 30 days after the last dose of INZ-701.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- ENERGY 2 (Study INZ701-105) is a multicenter, single-arm, open-label Phase 3 study to assess the efficacy and safety of INZ-701 in infants with ENPP1 Deficiency.
| Arm | Type | Receives |
|---|---|---|
| INZ-701 | Experimental | Drug: INZ-701Participants receive INZ-701 (rhENPP1-Fc) administered by subcutaneous injection once weekly at the protocol-specified dose. The visit final volume to administer (mL) is determined using protocol-defined parameters. |
Who may qualify
- Ages
- 0 years to 1 year
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Infant aged ≤ 1 year at the time of enrollment.
- Confirmed diagnosis of ENPP1 deficiency, based on genetic testing.
- Clinical features consistent with generalized arterial calcification of infancy (GACI) (e.g., vascular calcification or cardiac involvement).
- Medically stable to participate in a 52-week treatment study.
- Written informed consent provided by a parent or legal guardian.
Key exclusion criteria (5 listed)
- Receiving end-of-life or hospice care.
- Prior treatment with INZ-701, unless received through an approved expanded access program.
- Concurrent participation in another interventional clinical trial.
- Planned major surgery during the study period that would interfere with study participation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| INZ-701Also: (rhENPP1-Fc).Recombinant fusion protein that contains the extracellular domains of human ENPP1 coupled with an Fc fragment from an immunoglobulin gamma-1 (IgG1) antibody. | Drug | INZ-701 |
Primary outcome
To determine if INZ-701 increases inorganic pyrophosphate (PPi) levels
Time frame: 52 weeks (Baseline through Week 52)
For each subject, their change from baseline in Plasma Inorganic Pyrophosphate (PPi) concentration will be assessed.
To determine if INZ-701 increases overall survival
Time frame: 52 weeks (Baseline through Week 52)
For each subject, their change in overall survival based on time from date of birth to event of all-cause mortality will be assessed.
3 secondary outcomes
To determine if INZ-701 prevents decline in cardiac ejection fraction
Time frame: 52 weeks (Baseline through Week 52)
To determine if INZ-701 prevents heart failure
Time frame: 52 weeks (Baseline through Week 52)
To determine if INZ-701 attenuates progression of arterial calcification
Time frame: 52 weeks (Baseline through Week 52)
Results and safety
The study was stopped early (reason given: Following review of the totality of program data, the sponsor decided to discontinue development of INZ701. The decision was not related to safety.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Sep 2026.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director, MD study director
BioMarin Pharmaceutical
8 sites in 8 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing INZ-701 in people with Ectonucleotide Pyrophosphatase/phosphodiesterase1 Deficiency and Autosomal Recessive Hypophosphatemic Rickets, run by Inozyme Pharma at 8 sites in 8 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 29 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 8 sites in Brazil, France, Hungary, Italy, Saudi Arabia and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Following review of the totality of program data, the sponsor decided to discontinue development of INZ701. The decision was not related to safety.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine if INZ-701 increases inorganic pyrophosphate (PPi) levels (time frame: 52 weeks (Baseline through Week 52)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.