Inozyme Pharma halts infant ENPP1/ABCC6 trial of INZ-701 after enrolling 9

Inozyme Pharma's Phase 1b trial of INZ-701 in infants with ENPP1 Deficiency or ABCC6 Deficiency has been marked terminated in its ClinicalTrials.gov record, updated 2026-10-15. The study, known as ENERGY and registered as NCT05734196 (sponsor ID INZ701-104), began 2023-06-25 and was first posted 2023-02-17.

According to the record, the study was stopped by the sponsor before its planned completion following a review of data across indications and broader program considerations¹, and the termination was not related to participant safety.¹ Both primary completion and overall study completion are listed as 2026-09-29.

The trial tested INZ-701, described in the filing as a drug also known as rhENPP1-Fc, a recombinant fusion protein combining the extracellular domains of human ENPP1 with an Fc portion from an IgG1 antibody.¹ The design called for an open-label Phase 1 study measuring safety, tolerability, pharmacokinetics and pharmacodynamics of INZ-701 in infants with ENPP1 Deficiency or ABCC6 Deficiency.¹ Dosing ranged from Dose Level A at 0.2 mg/kg twice weekly up to Dose Level E at 1.8 mg/kg once weekly.¹

Final enrollment reached 9 participants (actual)¹, according to the design section. Primary outcomes tracked over the 52-week treatment period included the number of treatment-emergent adverse events¹, incidence of anti-drug antibodies¹, and left ventricular ejection fraction.¹

The study listed Inozyme Pharma as lead sponsor with BioMarin Pharmaceutical as collaborator, and enrolled at five sites across the United States, Spain, and the United Kingdom, per the registry's sponsor and site listings.