"This acquisition is particularly exciting as it immediately diversified our commercial stage portfolio and provided the opportunity to apply our demonstrated global commercial excellence," Alexion CEO Ludwig Hantson said on an investor call Tuesday morning.

Portola reported 2019 sales of $111.5 million for Andexxa, which is marketed as Ondexxya in Europe.

The drug treats excessive bleeding in patients taking so-called Factor Xa inhibitors, a type of anticoagulant.

"We have identified a clear path for accelerating and maximizing Andexxa's growth and are confident that we can leverage the full power of our established market access, commercial and operations organizations to enhance access and broaden the number of patients [helped] by Andexxa," Hantson said on the investor call.

In the question-and-answer portion of the call, SVB Leerink analyst Geoff Porges noted that Alexion's current products like Soliris are generally used chronically over the long term, while Andexxa is used once in an emergency setting.

"We have those strong networks in the hospital, and we have a capability, as we've shown over the years, of commercial excellence and market access," he said.