AstraZeneca's investigational enzyme replacement therapy efzimfotase alfa missed the primary endpoint in the phase 3 Hickory trial, failing to show statistically significant improvement over placebo on the six-minute walk test at Week 25 in adolescents and adults (12 years and older) with hypophosphatasia (HPP) who had not previously received Strensiq.1
The miss was attributed to better-than-expected placebo results in adult-onset HPP patients, though the drug showed nominally significant improvements in pediatric-onset subgroups and secondary endpoints like physical function and pain.1
Efzimfotase alfa aims to expand beyond Strensiq, which treats infantile- and juvenile-onset HPP, with potential peak sales of $3-5 billion, but adult market expansion faces setback.1
Positive results from Mulberry trial in treatment-naive children showed significant improvements in bone health and rickets severity; Chestnut trial in children switching from Strensiq confirmed tolerability and maintained benefits.1
Efzimfotase alfa offers dosing every two weeks subcutaneously vs. Strensiq's three to six times weekly, with lower manufacturing costs.1
Sources:
1. https://www.fiercebiotech.com/biotech/astrazenecas-phase-3-rare-disease-trial-misses-goal-denting-market-expansion-plan