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

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.

Individuals eligible to participate must meet all of the following inclusion criteria:

• Provide written or electronic informed consent after the nature of the study has been explained, and prior to any research-related procedures, per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Good Clinical Practice (GCP)
• Provide assent in accordance with local regulations, if <18 years of age
• Male or female, greater than 1 year of age
• Must have completed the protocol-required safety and PK/PD and/or efficacy period(s) of a previous INZ-701 clinical study in ENPP1 or ABCC6 Deficiency, as confirmed by the Sponsor
• Female participants of childbearing potential who are sexually active must be using or agree to use 1 highly effective form of contraception (per CTFG 2020) from at least 1 month before the first dose of INZ-701 through 30 days after last dose of INZ-701 (greater than 5 half-lives of INZ-701); participants must agree to not donate ova from the period following the first dose of INZ-701 through 30 days after the last dose of INZ-701
• Male participants who are sexually active must agree to use condoms from the period following the first dose of INZ-701 through 30 days after the last dose of INZ-701; participants must agree to not donate sperm from the period following the first dose of INZ-701 through 30 days after last dose of INZ-701
• In the opinion of the Investigator, able to complete all aspects of the study

Individuals who meet any of the following exclusion criteria will not be eligible to participate:

• In the opinion of the Investigator, presence of any clinically significant disease or laboratory abnormality not associated with ENPP1 Deficiency or ABCC6 Deficiency, that will preclude study participation and/or may confound interpretation of study results
• Known intolerance to INZ-701 or any of its excipients
• Concurrent participation in another interventional clinical study and/or has received an investigational drug other than INZ-701 within 5 half-lives or within 4 weeks prior to the first dose of INZ-701 in this study, whichever is longer, or use of an investigational device
• Pregnant, trying to become pregnant, or breastfeeding
• Male participants trying to father a child