Efzimfotase alfa (ALXN1850) for Hypophosphatasia
The FDA is expected to decide on Efzimfotase alfa for Hypophosphatasia in the first half of 2027, under a BLA from AstraZeneca (Alexion).
What is being decided
AstraZeneca (Alexion) has a BLA under FDA review for Efzimfotase alfa (ALXN1850) in Hypophosphatasia. Next-generation enzyme replacement therapy under priority review for patients aged 2 and older with hypophosphatasia, an inherited disorder of low alkaline phosphatase activity that leaves bones and teeth poorly mineralized. The application rests on 3 Phase 3 trials (HICKORY, MULBERRY and CHESTNUT). Alexion's older enzyme therapy, Strensiq, is already approved for HPP. AstraZeneca has disclosed only that it expects an FDA decision in the first half of 2027.
What each outcome would mean
An approval starts a second race rather than ending the first one: specialty pharmacy setup, insurance review, and patient assistance typically take weeks even when everything goes right. Our guide to the 90 days after a rare disease approval explains the timeline and the moves families can make on day 1.
A complete response letter would mean the FDA declined to approve in the application's current form. CRLs are often about manufacturing or data presentation rather than efficacy, and resubmission is common. Either way, this page updates with the outcome and what it means.
Frequently asked questions
When will the FDA decide on Efzimfotase alfa?
AstraZeneca (Alexion) expects a decision in the first half of 2027 but has not given an exact date.
Who disclosed it: AstraZeneca (Alexion). The FDA does not publish these dates.
Can it move: the FDA can act early, and a major amendment to the application can push the date back 3 months.
Source: AstraZeneca press release
What is Efzimfotase alfa being reviewed for?
AstraZeneca (Alexion) submitted a BLA for Efzimfotase alfa in Hypophosphatasia.
What to know: Next-generation enzyme replacement therapy under priority review for patients aged 2 and older with hypophosphatasia, an inherited disorder of low alkaline phosphatase activity that leaves bones and teeth poorly mineralized. The application rests on 3 Phase 3 trials (HICKORY, MULBERRY and CHESTNUT). Alexion's older enzyme therapy, Strensiq, is already approved for HPP. AstraZeneca has disclosed only that it expects an FDA decision in the first half of 2027.
How much will Efzimfotase alfa cost?
AstraZeneca (Alexion) has not announced a price. Drugmakers usually set it around approval.
Help paying: drugmaker programs and charity funds usually open at launch.
Find help: the patient assistance finder lists programs by insurance type.
What happens after the Efzimfotase alfa decision?
This page updates with the outcome the day it is announced.
If approved: getting the drug still takes time. Specialty pharmacy setup, insurance review and patient assistance often take weeks. Our guide covers what families can do on day 1.
If not approved: a complete response letter means the FDA declined the application in its current form. Many are about manufacturing or how data were presented, and companies often resubmit.
Where this date comes from
The FDA does not publish PDUFA dates; companies disclose them. This one comes from AstraZeneca press release. Dates can move, and the FDA can act early or late. This page rechecks against our calendar, which is re-verified daily.