Inozyme Pharma Shares New Data at ASBMR 2024

Inozyme Pharma, Inc., a clinical-stage biopharmaceutical company pioneering treatments for rare diseases impacting bone health and vascular function, is unveiling new data at the American Society for Bone and Mineral Research (ASBMR) 2024 Annual Meeting. The company is presenting four posters that illustrate the progression and impact of rare bone and blood vessel diseases in children. Key areas include the significant medical burden linked to ENPP1 Deficiency and early-onset ABCC6 Deficiency, fresh insights from a natural history study on ENPP1 Deficiency, and the initiation of a global registry to enhance understanding of these conditions.

Kurt Gunter, M.D., Chief Medical Officer at Inozyme Pharma, emphasizes the critical need for therapies targeting these rare diseases, noting that over half of infants with ENPP1 Deficiency do not survive past six months. Even those who do endure significant, lifelong complications. These new findings underscore the profound and multifaceted impacts of ENPP1 and ABCC6 Deficiencies, highlighting the necessity for treatments addressing both immediate and long-term systemic complications. Inozyme is focused on developing INZ-701, a potentially transformative therapy for affected patients and their families.

Christine O’Brien, co-president of GACI Global, echoed the urgency highlighted by the data, pointing out that the conditions' impact is more severe than previously understood. There is a particular emphasis on cardiovascular and musculoskeletal complications. GACI Global is collaborating with Inozyme to launch the PROPEL Registry, aimed at prospectively gathering clinical data and patient-reported outcomes. This effort will offer a comprehensive understanding of ENPP1 Deficiency and early-onset ABCC6 Deficiency's burden and progression.

The natural history study of ENPP1 Deficiency reveals it is a severe and progressive condition affecting blood vessels, soft tissues, and bones. Infants typically diagnosed with generalized arterial calcification of infancy (GACI Type 1) face a 50% mortality rate within six months. Key findings from the retrospective analysis of 84 patients indicate early-life complications, with 88% experiencing ectopic calcifications and 76% facing cardiovascular issues. Among the cohort, only a minority survived infancy, with many progressing to conditions like Autosomal Recessive Hypophosphatemic Rickets Type 2 (ARHR2). Nearly all survivors (95%) are expected to face lifelong cardiovascular, musculoskeletal, and other organ complications.

Another study, a retrospective observational analysis, examined the clinical events and interventions in patients with ENPP1 Deficiency (n=14) and early-onset ABCC6 Deficiency (n=9). This study confirms that both conditions result in significant cardiovascular complications and frequent medical interventions, including orthopedic surgeries and the need for hearing aids. Notably, 44% of early-onset ABCC6 Deficiency patients experienced strokes.

ENPP1 Deficiency is known to affect blood vessels, soft tissues, and bones, leading to conditions like GACI Type 1 in infants, with a high early mortality rate. Survivors often develop ARHR2 and osteomalacia, which cause pain and mobility issues, along with cardiovascular complications. It is estimated to affect about 1 in 64,000 pregnancies, though new findings suggest a higher prevalence due to severe symptoms in individuals with even one mutated gene copy. Currently, there are no approved therapies for this deficiency.

ABCC6 Deficiency mirrors ENPP1 Deficiency in its progression and severity, initially presenting as GACI Type 2 in infants. Survivors past infancy may face neurological and cardiovascular issues, evolving into pseudoxanthoma elasticum (PXE) in older individuals. PXE is characterized by abnormal mineralization affecting various organs and systems. The global prevalence of ABCC6 Deficiency is estimated to be between 1 in 25,000 to 1 in 50,000 individuals, with many more potentially affected when considering those with only one mutated gene copy. Like ENPP1, there are currently no approved treatments for ABCC6 Deficiency.

Inozyme Pharma is at the forefront of developing treatments for these rare diseases. Their leading candidate, INZ-701, is an ENPP1 Fc fusion protein enzyme replacement therapy designed to increase PPi and adenosine levels, targeting multiple diseases caused by deficiencies in these molecules. INZ-701 is currently under clinical development for treating ENPP1 Deficiency, ABCC6 Deficiency, and calciphylaxis, aiming to address the severe morbidity and mortality associated with these conditions.