Efzimfotase alfa (ALXN1850) for Hypophosphatasia
The FDA is expected to decide on Efzimfotase alfa for Hypophosphatasia in 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 three 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) has disclosed a decision window of First half of 2027 for Efzimfotase alfa in Hypophosphatasia, without an exact date.
What is Efzimfotase alfa being reviewed for?
AstraZeneca (Alexion) submitted a BLA for Efzimfotase alfa 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 three 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 happens after the Efzimfotase alfa decision?
If approved, availability is not immediate: specialty pharmacy setup, insurance review, and patient assistance typically take weeks even when everything goes right. If the FDA issues a complete response letter, the application was not approved in its current form; CRLs are often about manufacturing or data presentation rather than efficacy, and sponsors frequently resubmit. This page updates with the outcome either way.
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.