AstraZeneca (NASDAQ: AZN) reported results from three Phase III trials testing efzimfotase alfa, an investigational treatment for hypophosphatasia (HPP), a rare genetic bone disease.

The MULBERRY trial in treatment-naive pediatric patients aged 2 to 12 years met its primary endpoint, showing statistically significant improvement in bone health compared to placebo at week 25. The study measured bone health using the Radiographic Global Impression of Change Score.

The CHESTNUT trial demonstrated that pediatric patients who switched from existing treatment Strensiq to efzimfotase alfa maintained treatment benefits while showing acceptable safety and tolerability profiles.

The HICKORY trial in adolescents and adults aged 12 and older did not achieve statistical significance in its primary endpoint of Six-Minute Walk Test improvement compared to placebo. AstraZeneca attributed this to better-than-expected results in the placebo group of adult-onset HPP patients. However, the drug showed nominally significant improvements in fatigue measures across the study population and demonstrated benefits in mobility and physical function in prespecified subgroups of patients with pediatric-onset HPP.

The clinical program enrolled 196 patients across 22 countries, representing the first trials to include both pediatric- and adult-onset HPP patients. Efzimfotase alfa is designed as an enzyme replacement therapy with lower injection volume and less frequent dosing compared to the current treatment Strensiq.

The company plans to present the data at an upcoming medical meeting and submit the results to global regulatory authorities. AstraZeneca developed efzimfotase alfa through its Alexion rare disease division.