For each subject, their change from baseline in Plasma Inorganic Pyrophosphate (PPi) concentration will be assessed.

For each subject, their change in overall survival based on time from date of birth to event of all-cause mortality will be assessed.

For each subject, plasma PPi will be measured via a series of blood samples obtained throughout the study, comparing the subject's baseline value over time.

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.

For each participant, the presence of ADAs will be assessed and, if present, further evaluation will determine specificity and subtypes.

For each participant, an echocardiogram will be collected, and used to assess heart function. (Including measurement of left ventricular ejection fraction), and to identify any other abnormalities, for example, calcification of heart valves.

For each subject, variation of concentration of INZ-701 in the plasma will be measured via a series of blood samples obtained throughout the study, comparing the subject's baseline value over time.

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 subject's baseline value over time.

For each subject, clearance of INZ-701 from the body will be measured via a series of blood samples obtained throughout the study, comparing the subject's baseline value over time.

For each subject, plasma PPi will be measured via a series of blood samples obtained throughout the study, comparing the subject's baseline value over time.