Sanofi is to buy private US vaccines biotech Protein Sciences in a deal valued at up to $750 million, in a move to bolster its vaccines portfolio.

Under the terms of the agreement, the French drugmaker will make an initial payment of $650 million, and up to $100 million more on the attainment of certain pre specified milestones.

A key attraction is Protein Science’s Flublok Quadrivalent Influenza Vaccine (QIV), the only recombinant protein-based influenza vaccine to be approved by the US Food and Drug Administration (in October last year).

“The acquisition of Protein Sciences will allow us to broaden our flu portfolio with the addition of a non-egg based vaccine,” said David Loew, Sanofi executive vice president and head of Sanofi Pasteur, Sanofi’s vaccines division.

From the other side of the fence, Manon Cox, president and chief executive of the US biotech, said: As part of Sanofi Pasteur, we expect our Flublok influenza vaccine to benefit from Sanofi Pasteur’s expertise in the field of influenza vaccines.”

The acquisition is expected to close in the third quarter of this year, subject to customary regulatory approvals.

Fitusiran data
The news came a day after the French drugmaker’s global specialty care business, Sanofi Genzyme, presented data from a Phase II open-label extension study testing Alnylam-partnered fitusiran in patients with haemophilia A and B, with or without inhibitors.

Fitusiran is an investigational RNAi therapeutic targeting antithrombin for the treatment of patients with haemophilia A and B, that is designed to lower levels of antithrombin with the goal of promoting sufficient thrombin generation upon activation of the clotting cascade to restore haemostasis and prevent bleeding.

The data show that the safety and tolerability profile of the drug “remains encouraging, with no thromboembolic events, including during co-administration of replacement factor or bypassing agents”, the firm noted.

In addition, once-monthly subcutaneous administration of fitusiran achieved lowering of AT, increases in thrombin generation, and, in a post-hoc exploratory analysis, reductions in the median estimated annualised bleeding rate (ABR) in patients with and without inhibitors, it said.