The long-acting antibody – co-developed between Sanofi and AstraZeneca - is designed to protect all infants against RSV infections from birth through to their first RSV viral season. It is expected to launch in the US in time for the 2023/24 RSV season.
Direct antibody protection
RSV is a common respiratory virus, which can become serious in infants and older adults (it is the most common cause of bronchiolitis and pneumonia in children younger than 1 year old in the US, according to the CDC).
There are not currently any vaccines approved for RSV, with a one-dose of antibody instead offering several months of protection against severe disease in infants (Pfizer's maternal RSV vaccine candidate, however, is currently being reviewed by the FDA).
Beyfortus was developed to provide direct antibody protection to newborns and infants and protect them against lower respiratory tract infections caused by RSV.
Beyfortus’ Biologics License Application (BLA) is currently being reviewed with the US Food and Drug Administration (FDA), with a decision expected in Q3, 2023. It has already received marketing authorization from the EU, having been given the green light in November.
Sanofi champions enhanced agility for US rollout
A 2017 agreement had seen Sanofi and AstraZeneca team up on the development of the monoclonal antibody, with the two companies sharing all costs and profits equally.
This week, Sanofi and AstraZeneca announced the modification of the agreement, giving Sanofi ‘full commercial control of nirsevimab and enhanced agility in the US’.
The existing collaboration between the two companies remains in place outside the US.
Swedish Orphan Biovitrum AB – the Swedish company known as Sobi, which had obtained the right to participate in AstraZeneca’s share of US profits and losses in the drug as part of a 2018 deal for Synagis (palivizumab) – has now entered into a direct royalty agreement with Sanofi to share a portion of US net sales from nirsevimab.
Sanofi emphasises that the drug remains on schedule to launch in the US later this year, pending the FDA’s decision. “The new and updated contractual agreements do not impact nirsevimab registration and launch in the US, where all parties remain committed to making Beyfortus available for all infants in time for the 2023/24 RSV season,” says the company.