(Reuters) -British drugmaker GSK said on Wednesday it is restructuring a partnership with German biotech CureVac ( CVAC ) and will take control of several vaccines the two companies were jointly developing.

GSK said it will pay CureVac ( CVAC ) 400 million euros ($429.44 million) upfront and up to an additional 1.05 billion euros ($1.13 billion) in development, regulatory and sales milestones as well as tiered royalties.

The partnership began in 2020 during the COVID-19 pandemic and saw the two companies work together to develop vaccines for infectious diseases using messenger RNA (mRNA) technology.

GSK is one of the world's leading vaccine manufacturers. Wednesday's agreement reflects CEO Emma Walmsley's focus on vaccines and infectious diseases as a strategy to counter patent expiries and declining revenue from current bestselling medicines by the end of this decade.

CureVac ( CVAC ) is selling its major vaccine development projects, taking the upfront payment from GSK to boost its cash position and to focus on new cancer treatments.

It said in April it is laying off workers as it tries to move beyond its failure to develop an mRNA-based COVID vaccine during the pandemic.

GSK will now take forward the development of a vaccine for flu and another for COVID-19 that are in phase II trials and another for avian flu that is in phase I, or early stage, trials.

The licensing agreement announced Wednesday does not affect the size of GSK's stake in CureVac ( CVAC ), which stands at 130 million euros, a GSK spokesperson said.

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