FDA Grants Orphan Drug Designation to ENPP1 Deficiency Treatment, INZ-701

The US Food and Drug Administration (FDA) and European Medicines Agency’s (EMA) Committee for Orphan Medical Products (COMP) granted an orphan drug designation to INZ-701 for the treatment of ENPP1 deficiency, a serious, life-threatening calcification disorder.

INZ-701 is an enzyme replacement therapy developed by Inozyme Pharma intended for the treatment of calcification disorders of the circulatory system, bones, and kidneys. The therapy has exhibited the potential to generate plasma pyrophosphate (PPi) and to restore it to appropriate physiological levels, thus preventing calcification in the vasculature and kidneys and normalizing bone.

With ENPP1 deficiency, the ENPP1 gene fails to produce properly, consequently failing to regulate the PPi levels in the plasma. The disorder can manifest as either generalized arterial calcification of infancy (GACI) type 1 or autosomal recessive hypophosphatemic rickets type 2 (ARHR2).

GACI type 1 is more severe, oftentimes resulting in death due to the calcification and narrowing of large and medium-sized arteries. In fact, by 6 months of age, about half of patients experience heart failure. Less severe, ARHR2 typically manifests at a later age, in the post-infancy stage. However, it is known to cause crippling complications, such as rickets, weakened bones, repeated bone fractures, skeletal deformities, short stature, muscle weakness, fatigue, and bone pain.

“Orphan Drug Designation, both in the United States and the European Union, is an important regulatory milestone for Inozyme as we continue our quest to develop INZ-701 for patients with rare and life-threatening calcification disorders,” said Axel Bolte, co-founder and chief executive officer of Inozyme, in a recent statement. “The dual designations from the FDA and EMA provide crucial momentum for INZ-701, putting us in an excellent position to rapidly advance the clinical development program for this novel enzyme replacement therapy.”