AstraZeneca PLC's $39 billion venture into rare conditions yielded an early win for the U.K.'s largest drugmaker when an experimental pill for Wilson's disease hit its target in a late-stage study, paving the way for regulatory approval.
Best known for its cancer franchise — notably blockbuster drugs Lynparza, Tagrisso and Imfinzi, which are all set to lose patent exclusivity by the end of the decade — Cambridge, England-based AstraZeneca acquired Alexion, a Boston-based rare disease company, in December 2020. Among the pipeline of 11 molecules that it gained was the potential Wilson's disease therapy ALXN1840, one of the company's more advanced assets.
Wilson's disease, an inherited condition that affects 1 in 30,000 people, is caused by an excess of copper in the body. The phase 3 study, dubbed FoCus, showed ALXN1840 removed three times more copper than the current treatment options. If approved, the pill would be the first new medicine developed for the ultra-rare condition in over 30 years and the first targeted de-coppering therapy.
 |
AstraZeneca plans to submit the data for regulatory review in the coming months. The company has yet to disclose detailed results of the study or a potential price range for the product.
"With our potential therapy, it's one pill a day in the morning," said Brian Meltzer, the company's global medicine team lead for ALXN1840, in an interview. "If you catch this before symptoms, this can become just another chronic disease ... and you don't really have to think about it as part of your life every day, like so many other chronic diseases."
The current standard of care for Wilson's disease involves a heavy dosing regimen — up to four times a day on an empty stomach — with the potential for severe side effects, resulting in low levels of compliance.
ALXN1840 works by selectively binding to the copper and removing it from the body's tissues and blood. The FoCus study, published Aug. 26, showed that the once-a-day pill removed three times more copper than the chelation or zinc therapy, the current treatment options. The study showed no neurological worsening and mild to moderate side effects of a temporary elevation of liver enzymes.
"The data from AstraZeneca is exactly what we would have predicted, but it's great to see it actually appear in practice," said Genghis Lloyd-Harris, managing partner of Abingworth, in an interview. Abingworth was an early investor in ALXN1840 when the compound was being developed at Sweden's Wilson Therapeutics, which was acquired by Alexion in 2018. A specialist life sciences firm based in the U.K., Abingworth has $1.9 billion of assets under management and closed new funds with over $1 billion of commitments in 2021 alone.
Fewer than 200,000 people in the U.S. or fewer than five per 10,000 people in the EU can be diagnosed with a disease for it to be considered a rare or orphan disease, according to Cowen analyst Steve Scala. The U.S. National Institutes of Health lists 7,000 disorders that qualify and estimates that 25 million people in the U.S. are diagnosed with one.
To incentivize drug development for these diseases, also known as orphan diseases, regulators such as the U.S. Food and Drug Administration may offer faster reviews, longer periods of market exclusivity and favorable tax credits.
"It's relatively lower risk because the FDA is quite favorable," Lloyd-Harris said. "Even if the patent protection is weak, it's not going to matter if you have orphan drug designation. The trials are smaller, because by definition, they're rare. In some cases, the FDA is willing to accept surrogate endpoints for approval. And then there's premium pricing."
Current treatments for Wilson's cost about $300,000 to $400,000 a year and Lloyd-Harris said he would be surprised if AstraZeneca's medicine came in above that.
More than 450 orphan drugs have been approved in the U.S. in the 25 years since the orphan drug act was introduced, compared to the 10 products between 1973 and 1983. The European Commission also has been encouraging: More than 600 orphan designations have been granted by the Committee for Orphan Medicinal Products, and more than 50 orphan products have won either marketing authorization or a recommendation for approval from regulators, according to Cowen's Scala.
Difficult to diagnose
Still, Alexion's Meltzer said they are getting the sense that Wilson's disease is not actually as rare as one would think, after recruiting patients for a trial in record time.
"What we're learning is that this is a disease that's out there and probably part of its rarity is ... it's just not caught," Meltzer said. "It's masquerading as so many different things."
People with the disease experience symptoms ranging from liver malfunction and tremors to a change in personality that can be confused with schizophrenia as copper builds up in various tissues including the brain and the liver. Diagnosis of the condition is highly complex, with tell-tale Kayser-Fleischer rings around the cornea the only obvious indication of disease in some cases. Such symptoms are more commonly associated with Parkinson's disease or stroke, Meltzer said.
"We call ourselves the Think Wilson team, because that is exactly the problem," Meltzer said. "The challenge is, how do we get people to think about Wilson's disease?"
Ultimately, the ambition is to diagnose the disease as early as possible and scientists are researching a potential newborn screening test, said Meltzer, who prior to joining Alexion, had diagnosed a case of Wilson's by spotting the rings around the eyes of a patient presenting with severe schizophrenia. Other approaches being taken include Paris-based Vivet Therapeutics SAS's gene therapy, which is in earlier trials.