Pay AstraZeneca royalties on total sales of ovarian cancer drug Zejula: UK Court orders GSK's Tesaro

Tesaro had argued the royalty was payable only on sales that are for uses claimed or covered by the licensed patents, after AstraZeneca filed a UK lawsuit against GSK in 2021, asking for a bigger share of sales from Zejula.

In October 2012, Tesaro entered into license agreements with AstraZeneca, giving it exclusive rights to certain methods of treating patients with Zejula, developed by Tesaro with help from technology licensed from AstraZeneca.

The High Court of Justice Business and Property Court of England and Wales said on Wednesday Tesaro was obliged to pay AstraZeneca royalties "on all net sales of Zejula in each country in which there are licensed patents from the first commercial sale in that country," siding with AstraZeneca.

"We are disappointed by today's judgment and are considering our next steps," a GSK spokesperson said, while AstraZeneca said it was pleased with the decision.

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Latest results from GSK, which bought U.S.-based oncology focused firm Tesaro for $5.1 billion in 2018, showed Zejula sales in 2022 were 463 million pounds ($578.19 million).

Zejula belongs to a family of drugs called PARP inhibitors - which include AstraZeneca and Merck's Lynparza and Clovis Oncology's Rubraca.