AstraZeneca has reported positive results from the efzimfotase alfa Phase III clinical trial programme for hypophosphatasia (HPP), a rare metabolic bone disorder.
The global programme included two placebo-controlled, randomised trials and one active-controlled, open-label, randomised paediatric switch trial.
Discover B2B Marketing That Performs
Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.
It enrolled 196 children, adolescents, and adults with either paediatric-onset or adult-onset HPP throughout 22 countries.
Efzimfotase alfa, an investigational enzyme replacement therapy, is designed to offer reduced injection volume and less frequent dosing compared to Strensiq (asfotase alfa).
The MULBERRY Phase III trial, targeting children aged two to under 12 years with HPP who had not previously received Strensiq, met its primary endpoint.
It showed statistically significant and clinically meaningful improvement in bone health at week 25, as measured by the radiographic global impression of change (RGI-C) score compared to placebo.
Secondary endpoints, including the rickets severity score (RSS), physical function (six-minute walk test), and motor proficiency (paediatric outcomes data collection instrument or PODCI), also supported the benefit of efzimfotase alfa in this age group.
Results from the CHESTNUT Phase III trial indicated that efzimfotase alfa was well-tolerated in paediatric patients switching from Strensiq and maintained the established treatment benefit on bone health at week 25.
In the HICKORY Phase III trial involving adolescents and adults aged 12 years and above with HPP not previously treated with Strensiq, efzimfotase alfa showed numerical improvement in the six-minute walk test but did not achieve statistical significance in the primary endpoint.
However, nominally significant improvements were observed in fatigue reduction and mobility among subgroup populations.
Across the MULBERRY, CHESTNUT and HICKORY studies, the safety profile of efzimfotase alfa was acceptable.
Alexion, AstraZeneca Rare Disease CEO Marc Dunoyer said: “The efzimfotase alfa clinical programme, comprised of three global Phase III trials, was the first to include patients with both paediatric- and adult-onset HPP with heterogeneous manifestations beyond bone.
“We are encouraged by the improvements observed across this patient population who exhibit a wide range of severity and clinical characteristics. Collectively, these results support the potential for efzimfotase alfa to transform the treatment paradigm for people living with this rare disease.”
In December 2025, AstraZeneca’s combination therapy for locally advanced or metastatic non-small cell lung cancer did not meet the primary endpoint in a Phase III trial.
