A Phase 1/2 interventional study of INZ-701 in ATP-Binding Cassette Subfamily C Member 6 Deficiency, Pseudoxanthoma Elasticum and Generalized Arterial Calcification of Infancy, sponsored by Inozyme Pharma. Completed at 2 sites in 2 countries. Open to participants aged 18 Years to 69 Years. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by Inozyme Pharma (part of BioMarin Pharmaceutical) · Phase 1/2, Interventional, and Treatment
The purpose of this study is to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics PD) of multiple ascending doses of INZ-701, an ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) recombinant fusion protein, for the treatment of ABCC6 Deficiency. The goal of the study is to identify a dose regimen for further clinical development in the treatment of ABCC6 Deficiency.
INZ-701 is an ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) recombinant fusion protein in development for the treatment of ABCC6 Deficiency, a rare genetic disorder.
Study INZ701-201 is a Phase 1/2, multicenter, open-label, multiple ascending dose (MAD), dose-finding study followed by a long-term open-label Extension Period conducted in adults with ABCC6 Deficiency manifesting as Pseudoxanthoma elasticum (PXE). This study is designed to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of multiple ascending doses of INZ-701. The goal of the study is to identify a dose and dose schedule (number of doses per week) for further clinical development in ABCC6 Deficiency. No placebo will be used in this study.
Exploratory endpoints for the Extension Period of the study include evaluations of arterial and organ calcification, ophthalmologic, cardiac and renal parameters, and physical function as well as patient reported outcomes.
Subject participation consists of a Screening Period of up to 60 days, a 32-day Dose Evaluation Period, and an Extension Period during which subjects may continue to receive INZ-701 (with options for self-, caregiver-, or healthcare provider administration) until INZ-701 is approved and available in the country where the subject resides or until an alternative study for subjects to continue receiving study drug is available. During the Extension Period, follow-up visits will be conducted every 4 weeks until Week 48 of the Extension Period and then every 12 weeks (remote or in-clinic) until the subject leaves the study.
Subjects will complete a follow up visit 30 days after their last dose of INZ-701.
32 studies on the registry are indexed under Pseudoxanthoma Elasticum; 6 are open to participants now.
This study's enrollment of 10 is below the median of 21 across 16 interventional studies indexed under Pseudoxanthoma Elasticum.
Browse Pseudoxanthoma Elasticum studies →Inozyme Pharma is the lead sponsor of 12 studies on the registry; none are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 2 (33%) have results posted.
First submitted before Inozyme Pharma became part of BioMarin Pharmaceutical.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria
Individuals eligible to participate must meet all of the following inclusion criteria:
Individuals who meet any of the following exclusion criteria will not be eligible to participate:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study design of the Dose Evaluation Period is a MAD 3 + 3 with 3 dose cohorts. Based on nonclinical findings and nonclinical pharmacology modeling, the initial planned doses will be 0.2 mg/kg, 0.6 mg/kg, and 1.8 mg/kg, with a twice weekly dose regimen. During the Extension Period, INZ-701 administration will initially be at the dose and dose schedule assigned in the Dose Evaluation Period; however, the Sponsor may modify the assigned dose and/or dosing regimen in the Extension Period post-Week 48 based on cumulative review of safety and PK/PD data, including population PK. Study visits will be in-clinic every 4 weeks until Week 48 of the Extension Period and then every 12 weeks (remote or in-clinic) until the subject leaves the study. Subjects will complete an End of Study (EOS) Visit (Safety Follow-up Visit) 30 days after their last dose of INZ-701.
Drug: INZ-701
INZ-701 is a recombinant fusion protein that contains the extracellular domains of human ENPP1 coupled with an Fc fragment from an immunoglobulin gamma-1 (IgG1) antibody (rhENPP1-Fc).
Also known as: rhENPP1-Fc
Number of Participants Experiencing at Least One Treatment-Emergent Adverse Event (TEAE) During the Dose Evaluation Period
Number of participants experiencing at least one treatment-emergent adverse event (TEAE) during the Dose Evaluation Period. A TEAE was defined as any adverse event occurring or worsening after the first administration of INZ-701. Participants with one or more TEAEs were counted once regardless of the number of TEAEs experienced.
Time frame: Day 1 to Day 32
Number of Participants Experiencing at Least One Treatment-Emergent Adverse Event (TEAE) During the Extension Period
Number of participants experiencing at least one treatment-emergent adverse event (TEAE) during the Extension Period. A TEAE was defined as any adverse event occurring or worsening after the first administration of INZ-701. Participants with one or more TEAEs were counted once regardless of the number of TEAEs experienced. Treatment-emergent adverse events were summarized by NCI-CTCAE grade and relationship to INZ-701.
Time frame: Week 8 to Week 48
Number of Participants With Detectable Anti-Drug Antibodies (ADAs) During the Dose Evaluation Period
Number of participants with detectable anti-drug antibodies (ADAs) during the Dose Evaluation Period. Immunogenicity testing utilized a multi-tiered approach, including screening and confirmatory testing to determine ADA specificity and subtype.
Time frame: Day 1 to 32 days
Number of Participants With Detectable Anti-Drug Antibodies (ADAs) During the Extension Period
Number of participants with detectable anti-drug antibodies (ADAs) during the Extension Period. Immunogenicity testing utilized a multi-tiered approach, including screening and confirmatory testing to determine ADA specificity and subtype.
Time frame: Week 8 to Week 48
Area Under the Plasma Concentration Versus Time Curve (AUC) of INZ-701 During Dose Evaluation Period
Area under the plasma concentration-time curve (AUClast) of INZ-701 calculated from serial plasma concentration measurements obtained following dosing on Day 1 and Day 29.
Time frame: Day 1 and Day 29, using serial plasma samples collected from predose through 144 hours post-dose.
Maximum Plasma Concentration (Cmax) of INZ-701 During Dose Evaluation Period
Maximum plasma concentration (Cmax) of INZ-701 calculated from serial plasma concentration measurements obtained following dosing on Day 1 and Day 29.
Time frame: Day 1 and Day 29 (Cmax determined from serial plasma samples collected from predose through 144 hours post-dose).
Systemic Clearance of INZ-701 During the Dose Evaluation Period
Systemic clearance of INZ-701 was planned to be estimated from pharmacokinetic assessments on Day 1 and Day 29 using serial plasma samples collected from predose through 144 hours post-dose. A valid terminal phase rate constant could not be calculated because the terminal phase did not meet all prespecified noncompartmental analysis criteria for acceptance. Therefore, systemic clearance could not be reliably estimated.
Time frame: Day 1 and Day 29; serial plasma samples were planned from predose through 144 hours post-dose at each time point.
Change From Baseline in Plasma Inorganic Pyrophosphate (PPi) Levels During Dose Evaluation Period
Participant plasma samples were collected at screening, Day 1 to 7; Day 8, 11, 15, 18, 22; Day 29 to 31 and finally Day 32. Pre and post dose sampling was done on Day 1, Day 15 and Day 29. All plasma samples were measured using a sponsor developed assay
Time frame: Day 1 to Day 32
Change From Baseline in Plasma Inorganic Pyrophosphate (PPi) Levels During Extension Period
Participant plasma samples were collected pre-dose on Weeks 8, 12, 24, 36 and 48. All plasma samples were measured using a sponsor developed assay
Time frame: Week 8 to Week 48
Anticipated enrollment in the Phase 1 portion of the study is 9 subjects, assuming 3 cohorts are enrolled with no cohort expansion. The maximum number of subjects that could be enrolled in the study is 24.
| Milestone | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Started | 3 | 3 | 4 |
| Dose evaluation period (32 days) | 3 | 3 | 4 |
| Extension period (week 8 - week 48) | 3 | 3 | 3 |
| Completed | 3 | 3 | 2 |
| Not completed | 0 | 0 | 2 |
| Withdrew: Adverse event | 0 | 0 | 1 |
| Withdrew: Withdrawal by subject | 0 | 0 | 1 |
Number of participants experiencing at least one treatment-emergent adverse event (TEAE) during the Dose Evaluation Period. A TEAE was defined as any adverse event occurring or worsening after the first administration of INZ-701. Participants with one or more TEAEs were counted once regardless of the number of TEAEs experienced.
| Participants | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Number of Participants Experiencing at Least One Treatment-Emergent Adverse Event (TEAE) During the Dose Evaluation Period | 1 | 3 | 3 |
Number of participants experiencing at least one treatment-emergent adverse event (TEAE) during the Extension Period. A TEAE was defined as any adverse event occurring or worsening after the first administration of INZ-701. Participants with one or more TEAEs were counted once regardless of the number of TEAEs experienced. Treatment-emergent adverse events were summarized by NCI-CTCAE grade and relationship to INZ-701.
| Participants | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Number of Participants Experiencing at Least One Treatment-Emergent Adverse Event (TEAE) During the Extension Period | 1 | 3 | 3 |
Number of participants with detectable anti-drug antibodies (ADAs) during the Dose Evaluation Period. Immunogenicity testing utilized a multi-tiered approach, including screening and confirmatory testing to determine ADA specificity and subtype.
| Participants | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Number of Participants With Detectable Anti-Drug Antibodies (ADAs) During the Dose Evaluation Period | 1 | 1 | 0 |
Number of participants with detectable anti-drug antibodies (ADAs) during the Extension Period. Immunogenicity testing utilized a multi-tiered approach, including screening and confirmatory testing to determine ADA specificity and subtype.
| Participants | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Number of Participants With Detectable Anti-Drug Antibodies (ADAs) During the Extension Period | 2 | 2 | 3 |
Area under the plasma concentration-time curve (AUClast) of INZ-701 calculated from serial plasma concentration measurements obtained following dosing on Day 1 and Day 29.
| AUClast (hr*ng/mL) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Day 1 | 11594 ± 1143.6 | 90670 ± 93043.2 | 280074 ± 164087.8 |
| Day 29 | 35106 ± 18004 | 170554 ± 99407.9 | 1343805 ± 534937.0 |
Maximum plasma concentration (Cmax) of INZ-701 calculated from serial plasma concentration measurements obtained following dosing on Day 1 and Day 29.
| Cmax (ng/mL) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Day 1 (Predose to 144 Hours Post-Dose) | 170 ± 19.9 | 725 ± 669 | 2091 ± 1212.2 |
| Day 29 (Predose to 144 Hours Post-Dose) | 534 ± 229 | 2585 ± 1379.6 | 21264 ± 8228.8 |
Systemic clearance of INZ-701 was planned to be estimated from pharmacokinetic assessments on Day 1 and Day 29 using serial plasma samples collected from predose through 144 hours post-dose. A valid terminal phase rate constant could not be calculated because the terminal phase did not meet all prespecified noncompartmental analysis criteria for acceptance. Therefore, systemic clearance could not be reliably estimated.
No measurements were reported for this outcome.
Participant plasma samples were collected at screening, Day 1 to 7; Day 8, 11, 15, 18, 22; Day 29 to 31 and finally Day 32. Pre and post dose sampling was done on Day 1, Day 15 and Day 29. All plasma samples were measured using a sponsor developed assay
| nM | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Day 1 - 6 hrs Post-dose | 710.7 ± 1059.27 | 7.0 ± 63.22 | 123.8 ± 760.46 |
| Day 32/Early Termination - Pre-dose | -185.7 ± 156.13 | -95.7 ± 80.83 | 254.3 ± 430.45 |
Participant plasma samples were collected pre-dose on Weeks 8, 12, 24, 36 and 48. All plasma samples were measured using a sponsor developed assay
| nM | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| Week 8 - Pre-dose | -107.5 ± 4.95 | -27.7 ± 143.07 | 508.7 ± 324.17 |
| Week 48 - Pre-dose | 514.3 ± 678.74 | 98.3 ± 1113.80 | 872.5 ± 38.89 |
Collected over From baseline through to Dose Evaluation Period (Day 32) and through to Week 48. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Cohort 1: Dose Level #1 | 0/3 (0%) | 0/3 (0%) | 1/3 (33.3%) |
| Cohort 2: Dose Level #2 | 0/3 (0%) | 0/3 (0%) | 3/3 (100%) |
| Cohort 3: Dose Level #3 | 0/4 (0%) | 0/4 (0%) | 3/4 (75%) |
| Event | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 |
|---|---|---|---|
| FatigueGeneral disorders | 0/3 | 3/3 | 0/4 |
| COVID-19Infections and infestations | 1/3 | 2/3 | 1/4 |
| Injection site reactionSkin and subcutaneous tissue disorders | 1/3 | 0/3 | 1/4 |
| PresyncopeGeneral disorders | 1/3 | 0/3 | 1/4 |
| Upper respiratory tract infectionRespiratory, thoracic and mediastinal disorders | 1/3 | 1/3 | 0/4 |
| Age, Categorical(Participants) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| <=18 years | 0 | 0 | 0 | 0 |
| Between 18 and 65 years | 3 | 2 | 4 | 9 |
| >=65 years | 0 | 1 | 0 | 1 |
| Age, Continuous(years) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| Mean | 41.7 ± 13.58 | 60.7 ± 7.77 | 50.3 ± 3.20 | 50.8 ± 10.87 |
| Sex: Female, Male(Participants) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| Female | 1 | 3 | 2 | 6 |
| Male | 2 | 0 | 2 | 4 |
| Race (NIH/OMB)(Participants) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 | 0 |
| White | 3 | 3 | 4 | 10 |
| More than one race | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| Hispanic or Latino | 1 | 1 | 0 | 2 |
| Not Hispanic or Latino | 2 | 2 | 4 | 8 |
| Unknown or Not Reported | 0 | 0 | 0 | 0 |
| Region of Enrollment(participants) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| United States | 1 | 3 | 2 | 6 |
| United Kingdom | 2 | 0 | 2 | 4 |
| Baseline Plasma Inorganic Pyrophosphate (PPi) Level(nM) | Cohort 1: Dose Level #1 | Cohort 2: Dose Level #2 | Cohort 3: Dose Level #3 | Total |
|---|---|---|---|---|
| Mean | 851.0 ± 174.32 | 1075.7 ± 90.90 | 931.5 ± 218.11 | 950.6 ± 182.01 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Apr 2022 to primary completion in Jul 2024, 26 months.
Results were first posted in Oct 2026, 2 years 3 months after primary completion.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Efmirenpase alfa