Inozyme Pharma Announces Positive Interim Data from Ongoing Phase 1/2 Trials of INZ-701 in Adults with ENPP1 Deficiency and ABCC6 Deficiency (PXE) - Seite 3

• Rapid, significant, and sustained increase in PPi levels observed in all patients and significant elevation in PPi maintained for up to 18 months.
• Long half-life of approximately 126 hours and drug accumulation as shown by a greater than dose proportional exposure suggests the potential for once weekly dosing.

Safety Data

• INZ-701 was generally well-tolerated and exhibited a favorable safety profile, with no serious or severe adverse events attributed to INZ-701 and no adverse events leading to study withdrawal.
• 3/9 patients experienced mild adverse events related to INZ-701.
  • Injection site reactions (bruising, hemorrhage, pain, pruritus, and/or swelling) occurred in 2/9 patients.
  • Other related adverse events included decreased appetite and fatigue.
• There were two serious adverse events not related to INZ-701.
• All nine patients enrolled in the Phase 2 portion of the trial, two of whom subsequently withdrew from the study. The study withdrawals were not related to an adverse event.
• Seven patients remain in the trial and continue on home self-administration of INZ-701 treatment.
• Time on study ranged from 98 to over 638 days. Total time on treatment across all cohorts corresponds to approximately 9 patient-years.

Anti-Drug Antibody (ADA) Data

INZ-701 exhibited a favorable immunogenicity profile with low titers of non-neutralizing ADAs observed in 7/9 patients. The ADA levels were transient in 3/7 patients.

ABCC6 Deficiency

Ten patients were enrolled in the ongoing Phase 1/2 trial across three dose cohorts of INZ-701 (0.2 mg/kg (n=3), 0.6 mg/kg (n=3), and 1.8 mg/kg (n=4)). For trial design details, please see the section entitled “INZ-701 in ABCC6 Deficiency Phase 1/2 Clinical Trial Design” below.

Exploratory Efficacy Data

Clinical outcome measures were collected to provide evidence of clinical benefit and to inform the design of future trials in adults. Notable changes in GIC, a PRO, were observed, including:

• The majority of timepoints showed improvement in GIC scores reported by P-GIC and C-GIC.
• All patients (9/9) showed improvement on C-GIC, and 7/9 patients showed improvement from baseline on P-GIC at last follow-up.

Pharmacodynamic (PD) and Pharmacokinetic (PK) Data

• Rapid and significant increase in PPi levels observed in all cohorts with a dose response observed.
• PPi showed sustained increase in the highest dose cohort to levels comparable to those observed in a study of healthy subjects.²
• PK properties were consistent with those observed in the Phase 1/2 clinical trial in adults with ENPP1 Deficiency.