Inozyme Pharma, Inc. announced dosing of the first patient in its ENERGY-1 trial, a Phase 1b clinical trial of INZ-701 in infants with ENPP1 Deficiency. ENERGY-1 is a Phase 1b, single arm, open label clinical trial designed to primarily assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of INZ-701 in infants with ENPP1 Deficiency. The trial is expected to enroll up to eight infants between the ages of one and 12 months across multiple sites in the United States and Europe.

Patients will receive subcutaneous doses of INZ-701 during the treatment period of 52 weeks and may continue to receive INZ-701 in an extension period beyond 52 weeks. Doses range from 0.2 mg/kg once weekly through 0.6 mg/kg twice weekly, with the ability to increase the dose further depending on the results of PK/PD and safety data. Additional outcome measures include evaluation of plasma pyrophosphate (PPi) levels, survival, growth, development, functional performance, cardiac function, and exploratory biomarkers.

The Company plans to host a conference call in July 2023 to provide a program update on global development plans for INZ-701 in patients with ENPP1 Deficiency. The update will cover regulatory agreements on pivotal trial designs, including plans for pivotal trial of INZ-701 in pediatric patients which is planned to begin in Third Quarter 2023, an overview of the ENPP1 Deficiency opportunity, and ongoing patient identification efforts. ENPP1 Deficiency is a progressive condition that manifests as a spectrum of diseases.

The estimated genetic prevalence of ENPP1 Deficiency is approximately 1 in 64,000 pregnancies. Individuals who present in utero or in infancy are typically diagnosed with generalized arterial calcification of infancy (GACI), which is characterized by extensive vascular calcification and intimal proliferation (overgrowth of smooth muscle cells inside blood vessels), resulting in myocardial infarction, stroke, or cardiac or multiorgan failure. Approximately 50% of infants with ENPP1 Deficiency die within six months of birth.

Children with ENPP1 Deficiency typically develop rickets, a condition diagnosed as autosomal-recessive hypophosphatemic rickets type 2 (ARHR2), while adults can develop osteomalacia (softened bones). ARHR2 and osteomalacia lead to pain and mobility issues. Patients can also exhibit signs and symptoms of hearing loss, arterial and joint calcification, and cardiovascular complications.

There are no approved therapies for ENPP1 Deficiency. INZ-701, a recombinant Fc fusion protein, is an ENPP1 enzyme replacement therapy in development for the treatment of rare disorders of the vasculature, soft tissue, and skeleton. In preclinical studies, the experimental therapy has shown potential to prevent pathologic mineralization and intimal proliferation (the overgrowth of smooth muscle cells inside blood vessels), which can drive morbidity and mortality in devastating genetic disorders such as ENPP1 Deficiency and ABCC6 Deficiency.

INZ-701 is currently in Phase 1/2 clinical trials for the treatment of ENPP1 Deficiency and ABCC6 Deficiency.