AstraZeneca's $39B Alexion buyout bears fruit, yielding late-phase win for potential blockbuster rare disease drug

The chances of AstraZeneca’s $39 billion bet on Alexion paying off just ticked up a notch. ALXN1840, a drug Alexion has hailed as a potential blockbuster, has hit the primary endpoint in a phase 3 rare disease trial, clearing the path for a regulatory filing.

Alexion picked up ALXN1840 in its $855 million takeover of Wilson Therapeutics as part of a push by CEO Ludwig Hantson, Ph.D., to rebuild the pipeline after earlier R&D missteps left the company unprepared for a forecasted downturn in sales of Soliris. After buying the asset, Alexion began a phase 3 clinical trial designed to show superiority over standard of care in Wilson disease and support blockbuster sales.

AstraZeneca, of course, wrapped up the acquisition of Alexion back in July. 

Top-line findings from the trial are now in. The study showed ALXN1840 is better than existing Wilson drugs—trientine, penicillamine, zinc or a combination of the medicines—at mobilizing copper from tissues. Wilson patients suffer from the loss of function in a copper-binding protein, causing the accumulation of the element. As copper accumulates, patients suffer outcomes including liver disease, neurological problems and psychiatric disturbances.      

Existing drugs are designed to increase the amount of copper excreted in urine or cut gastrointestinal uptake of the element. However, compliance with the existing medicines is a problem, and neurological symptoms can worsen despite treatment. 

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ALXN1840 is designed to selectively bind to copper, potentially enabling it to act faster than current options, clear the metal from tissues, rather than just blood, and thereby provide a better risk-benefit profile. The phase 3 results suggest ALXN1840 can deliver on that promise and become a new option for the estimated 10,000 or so Wilson patients in the U.S. and Europe.

AstraZeneca is now preparing to send the data to regulators for review “in the coming months.” The time frame positions AstraZeneca to provide the first new treatment for Wilson in years, but it may be joined by others before long. Vivet Therapeutics, which is partnered with Pfizer, and Ultragenyx each have Wilson gene therapies in early development.