French drugmaker Sanofi is gaining access to a new type of flu vaccine after agreeing to buy Protein Sciences, a privately held vaccines biotechnology company based in Meriden, Connecticut, USA.

Protein Science’s Flublok Quadrivalent Influenza Vaccine (QIV) is the only recombinant protein-based flu vaccine to be approved by the US Food and Drug Administration (FDA). The FDA gave its approval to Flublok in October 2016.

Under the terms of the transaction, Sanofi will make an initial payment of $650 million and up to another $100 million if certain milestones are achieved.

David Loew, Sanofi’s executive vice president and head of Sanofi Pasteur, the drugmaker’s vaccines division, said the acquisition will allow it to broaden its flu portfolio with a non-egg based vaccine. Flublok does not use the influenza virus or chicken eggs in the manufacturing process.

President and CEO of Protein Sciences, Manon Cox, added that the company is actively looking for an opportunity to grow its business, particularly in the US, and he expects Flublok to benefit from Sanofi Pasteur’s expertise in influenza vaccines.

Protein Sciences’ board of directors has unanimously approved the merger, as have most of its shareholders. The transaction is expected to close in the third quarter, subject to regulatory approvals.

In separate news, Sanofi Genzyme and US biopharma Alnylam Pharmaceuticals have presented data from an ongoing Phase II open-label extension study on fitusiran in patients with the blood disorder hemophilia A and B, with or without inhibitors.

Fitusiran is an investigational RNAi therapeutic designed to reduce levels of antithrombin (AT) and promote sufficient thrombin generation to restore hemostasis and prevent bleeding. AT is a protein molecule that inactivates several enzymes of the body’s coagulation system. The data is said to have shown that the drug’s safety and tolerability profile remains encouraging, with monthly subcutaneously administered fitusiran seen to have lowered AT levels and increased thrombin generation.

Based on these results, the companies will initiate a Phase III program, of which initial results are expected in mid-to-late 2019.