Enzyme-replacement therapy in life-threatening hypophosphatasia

Area of Science:

• Biochemistry
• Genetics
• Pediatric Medicine

Background:

• Hypophosphatasia (HPP) is a rare genetic disorder caused by mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene.
• This leads to the accumulation of inorganic pyrophosphate, causing rickets and osteomalacia, often with severe consequences in infants.
• Currently, there is no approved medical therapy for hypophosphatasia.

Purpose of the Study:

• To evaluate the efficacy and safety of ENB-0040, a bone-targeted, recombinant human TNSALP, in infants and young children with life-threatening hypophosphatasia.
• To assess the healing of rickets, motor and cognitive development, respiratory function, and safety outcomes.

Main Methods:

• A multinational, open-label study enrolled infants and young children with severe HPP.
• Treatment involved ENB-0040, with radiographic assessment of rickets healing as the primary endpoint.
• Pharmacokinetics, pharmacodynamics, developmental milestones, and safety were also evaluated.

Main Results:

• Nine of 11 patients showed rickets healing at 6 months, with improvements in developmental and pulmonary function.
• Key TNSALP substrates, inorganic pyrophosphate and pyridoxal 5'-phosphate, decreased.
• No serious drug-related adverse events were observed; some patients developed low-titer antibodies without clinical impact.

Conclusions:

• ENB-0040, an enzyme-replacement therapy, demonstrated significant improvements in skeletal, pulmonary, and physical function in infants with severe HPP.
• The study suggests ENB-0040 is a promising therapeutic option for this debilitating genetic bone disease.
• Further research and clinical trials are warranted to confirm these findings.