Inozyme Pharma Announces JBMR Plus Publication Demonstrating Real-World Impact of ENPP1 Deficiency

- Data from the largest retrospective analysis of ENPP1 Deficiency provides insights into the evolution of the disease’s serious cardiovascular and musculoskeletal complications -

- Findings highlight the urgent need for early and improved diagnosis, care and treatments that address the long-term systemic effects of ENPP1 Deficiency -

BOSTON, April 10, 2025 (GLOBE NEWSWIRE) --Inozyme Pharma, Inc.(Nasdaq: INZY) (“the Company” or “Inozyme”), a clinical-stage biopharmaceutical company developing innovative therapeutics for rare diseases that affect bone health and blood vessel function, today announced the publication of a paper titled, “Phenotypic characterization of ENPP1 deficiency: generalized arterial calcification of infancy and autosomal recessive hypophosphatemic rickets type 2” inJBMR Plusthat characterizes the severity and progression of ENPP1 Deficiency. Inozyme collaborated with leading disease experts Carlos Ferreira, M.D., of the National Institutes of Health (NIH), Frank Rutsch, M.D., of Münster University Children’s Hospital and other global contributors to collect natural history data in the largest retrospective analysis of ENPP1 Deficiency published to date.

“This comprehensive study illustrates the devastating, systemic nature of ENPP1 Deficiency, highlighting its severe cardiovascular implications starting as early as infancy and evolving to significant musculoskeletal complications over a lifetime as individuals go through childhood, adolescence, and then adulthood,” said Matt Winton, Ph.D., Senior Vice President and Chief Operating Officer of Inozyme Pharma. “The findings underscore a critical need for earlier diagnosis and effective treatments. Our lead investigational therapy, INZ-701, is uniquely positioned as a potential transformative therapy to address the underlying causes and systemic impacts of this severe condition.”

ENPP1 Deficiency frequently manifests as Generalized Arterial Calcification of Infancy (GACI) or Autosomal Recessive Hypophosphatemic Rickets Type 2 (ARHR2), representing age-dependent phenotypes that evolve on a continuum over a lifetime. Of the 84 individuals with ENPP1 Deficiency in the analysis, 51 had a recorded diagnosis of GACI, only 19 of whom survived beyond infancy; 22 were diagnosed with GACI and progressed to ARHR2; and 11 presented initially with ARHR2. Importantly, a majority of patients (60%) with a history of GACI had prenatal findings, and a GACI diagnosis (median age of 0.8 months at diagnosis) was usually associated with early-onset arterial calcification, respiratory distress, heart failure, and hypertension, necessitating acute inpatient care. Additional findings from the publication included:

These findings highlight that ENPP1 Deficiency is a progressive, lifelong condition requiring coordinated, multidisciplinary care. Even for those who survive infancy, the majority will face ongoing cardiovascular, skeletal, and systemic complications, underscoring the need for early diagnosis and long-term management to improve outcomes.

ENPP1 Deficiency is a serious and progressive rare disease that affects blood vessels, soft tissues, and bones. Individuals who present in utero or in infancy are typically diagnosed with generalized arterial calcification of infancy (GACI Type 1), with about 50% of these infants not surviving beyond six months. Children with this condition typically develop autosomal-recessive hypophosphatemic rickets type 2 (ARHR2), while adolescents and adults may develop osteomalacia, or softened bones. ARHR2 and osteomalacia cause pain and difficulty with movement. Additionally, patients may experience hearing loss, calcification in arteries and joints, and heart problems. ENPP1 Deficiency is an autosomal recessive disease and biallelic mutations are estimated to occur in approximately 1 in 64,000 pregnancies worldwide. Many individuals with just one copy of the mutated gene (monoallelic ENPP1 Deficiency) exhibit severe symptoms, suggesting that the worldwide prevalence of ENPP1 Deficiency may be much higher than current estimates. Currently, there are no approved therapies for ENPP1 Deficiency.

Inozyme Pharma is a clinical-stage biopharmaceutical company dedicated to developing innovative therapeutics that target the PPi-Adenosine Pathway, a key regulator of bone health and blood vessel function. Disruptions in this pathway underlie a range of severe diseases, including ENPP1 Deficiency. Our lead investigational therapy, INZ-701, is an ENPP1 Fc fusion protein enzyme replacement therapy (ERT) designed to restore PPi and adenosine levels. INZ-701 is currently in late-stage clinical development in ENPP1 Deficiency, with the potential to expand into additional indications where deficiencies in the PPi-Adenosine Pathway contribute to disease pathology. Through our pioneering work, we aim to transform treatment options for patients affected by these devastating conditions.

For more information, please visithttps://www.inozyme.com/or follow Inozyme onLinkedIn,X, andFacebook.

Investors:Inozyme PharmaStefan Riley, Senior Director of IR and Corporate Communications(617) 461-2442stefan.riley@inozyme.com

Media:Biongage CommunicationsTodd Cooper(617) 840-1637todd@biongage.com

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