BioMarin to acquire Alesta Therapeutics for US$490M to secure HPP drug candidate

USA—BioMarin Pharmaceutical has agreed to acquire rare disease drug developer Alesta Therapeutics for up to US$490 million, including US$275 million upfront and as much as US$215 million in development and regulatory milestones.

The deal will give BioMarin access to ALE1, Alesta’s lead clinical-stage candidate for hypophosphatasia (HPP), a rare genetic bone disorder.

Deal to add ALE1 to BioMarin’s pipeline

BioMarin expects the transaction to close in the third quarter of 2026.

Before completion, Alesta plans to spin out all assets unrelated to ALE1, although it has not disclosed details of the rest of its pipeline or research programmes outside HPP.

Following the acquisition, BioMarin will add ALE1 to its Skeletal Conditions Business Unit.

The company is pursuing the deal as part of its strategy to expand its portfolio of treatments for rare diseases.

HPP is an inherited metabolic disorder caused by mutations in the ALPL gene.

These mutations result in low levels of alkaline phosphatase (ALP), an enzyme required for normal bone and tooth mineralisation.

Reduced ALP activity causes inorganic pyrophosphate to accumulate, interfering with mineralisation and potentially resulting in weak bones, fractures and dental problems.

Oral treatment targets inorganic pyrophosphate

ALE1 is an orally administered small-molecule drug designed to reduce inorganic pyrophosphate levels.

The candidate is currently being studied in an ongoing Phase I/IIa clinical trial (NCT07179640), which aims to enrol 120 healthy adults and adults with HPP.

If approved, ALE1 could offer a different treatment approach from the only currently approved HPP medicine, AstraZeneca’s Strensiq (asfotase alfa).

Strensiq is an enzyme replacement therapy administered by injection. ALE1 would be the first oral treatment for HPP and the first to directly target inorganic pyrophosphate.

William Blair analysts described ALE1 as a strategic addition to BioMarin’s skeletal disease portfolio.

They noted that Strensiq generated approximately US$1.7 billion in revenue in 2025, highlighting the commercial opportunity in HPP.

The analysts also said ALE1’s oral administration and distinct mechanism could give it a competitive position if it reaches the market.

However, they noted that the candidate still needs to progress through Phase III development, making the acquisition a longer-term investment.

Second major pipeline deal

The Alesta transaction is BioMarin’s second major pipeline expansion this year.

In April, the company completed its US$4.8 billion acquisition of Amicus Therapeutics, gaining access to treatments for Fabry and Pompe diseases.

BioMarin CEO Alexander Hardy described ALE1 as a “strong strategic fit” for the company.

He said the opportunity addresses a significant unmet medical need while giving BioMarin an asset with the potential to serve a large rare disease patient population.

Hardy added that the company would continue pursuing similar clinical-stage opportunities to support long-term growth.

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