AstraZeneca Gets FDA Approval in Boost to Rare Disease Franchise

AstraZeneca plant_iStock, Roland Magnusson

Pictured: AstraZeneca's production plant in Sweden/iStock, Roland Magnusson

AstraZeneca announced Monday that it has secured FDA approval for an add-on to its blockbuster rare disease franchise, providing a potential differentiator as it tries to hold off competition from Novartis, Roche and biosimilars.

The approval covers danicopan, an oral, first-in-class factor D inhibitor that AstraZeneca’s rare disease unit has developed as a treatment for a subset of adults with paroxysmal nocturnal haemoglobinuria (PNH). The FDA approved the drug as an add-on therapy for AstraZeneca’s Ultomiris (ravulizumab) and Soliris (eculizumab).

Between 10% and 20% of PNH patients experience clinically significant removal of red blood cells outside of the blood vessels, a condition called extravascular haemolysis (EVH), and continued anemia symptoms when taking C5 inhibitors such as Ultomiris and Soliris. People with EVH can require blood transfusions to manage the condition.

Danicopan, which AstraZeneca will market as Voydeya, is designed to reduce the need for transfusions and otherwise improve outcomes in EVH patients. AstraZeneca validated danicopan in a Phase III clinical trial that linked the factor D inhibitor to a statistically significant improvement in hemoglobin levels after 12 weeks. Later, the drug developer showed the improvements persisted through 48 weeks.

Alexion added danicopan to its pipeline when it paid $930 million for Achillion Pharmaceuticals in 2019. Ownership of the drug molecule changed again after AstraZeneca agreed to buy Alexion for $39 billion in 2020.

Buying Alexion gave AstraZeneca a PNH franchise. Alexion had the PNH market largely to itself for years, helping it to turn Soliris and Ultomiris into blockbusters, but the landscape is shifting. Alexion CEO Marc Dunoyer named the introduction of Soliris biosimilars as the main headwind facing the business on an AstraZeneca earnings call in February 2024.

AstraZeneca is working to transition patients from Soliris to Ultomiris to soften the impact of biosimilars on sales. Conversion of Soliris to Ultomiris in PNH is “in the magnitude of 80%,” Dunoyer said. Sales of Soliris fell 16% to $3.1 billion last year, while sales of Ultomiris rose more than 50% to almost $3 billion.

In addition, AstraZeneca faces branded rivals for the PNH market. Apellis brought Empaveli (pegcetacoplan) to market in 2021. Novartis won FDA approval for the factor B inhibitor Fabhalta (iptacopan) late last year after linking it to improved outcomes in patients who had residual anemia, while receiving a stable regimen of an anti-C5 therapy such as Soliris or Ultomiris. Roche has filed for approval of a C5 drug.

Nick Paul Taylor is a freelance pharmaceutical and biotech writer based in London. He can be reached on LinkedIn.

Back to news