Swedish Orphan Biovitrum AB has entered into an agreement to buy US rights to AstraZeneca’s Synagis, licensed for the prevention of serious lower respiratory tract infection caused by respiratory syncytial virus (RSV).

Sobi will commercialise Synagis in the US and around 130 AZ employees will transfer to the company as part of the move.

The deal also gives Sobi the right to participate in AstraZeneca’s share of US profits and losses related to potential new medicine MEDI8897, which AZ will continue to develop in collaboration with Sanofi Pasteur, the vaccines division of Sanofi.

“We continue to streamline our portfolio, allowing AstraZeneca to allocate resources more effectively, while Sobi’s focus on Synagis will enable infants in the US to continue benefiting from this important treatment,” said AZ’ chief executive Pascal Soriot.

“Meanwhile, the successful development and commercialisation of MEDI8897 remains important for AstraZeneca.”

“I am excited about adding Synagis to our portfolio as it remains the only product preventing RSV infection in this vulnerable patient group with a great medical need,” added Sobi’s president and chief executive Guido Oelkers.

“The addition of Synagis will become an important catalyst for Sobi’s future development and will form a powerful platform for growth in rare diseases.”

Under the terms of the deal, AZ stands to receive an upfront consideration of $1.5 billion, consisting of $1.0 billion in cash and $500m in ordinary shares of Sobi upon completion, equating to an ownership interest of 8%.

The drug giant will also receive up to $470 million in sales-related payments for Synagis, a $175-million milestone following the submission of the Biologics License Application for MEDI8897; potential net payments of around $110 million on achievement of other MEDI8897 profit and development-related milestones; and a total of $60 million in non-contingent payments for MEDI8897 during 2019-2021.