Weil Gotshal & Manges has acted on a second major M&A transaction in a week for client Sanofi, as the pharma giant returns to the acquisition trail.

The US firm won the top role for Sanofi, which today revealed it would buy Ablynx for just under €4bn (£3.5bn).

The announcement comes just a week after Weil acted for Sanofi on its $11.6bn deal with Bioverativ, with both transactions expanding Sanofi’s capabilities for treating blood disorders.

US-based corporate chair Michael Aiello led the deal team from Weil Gotshal, alongside partner Matthew Gilroy.

Partner Adé Heyliger also advised from the public company advisory group in Washington DC, while partner Jeffery Osterman worked on IP matters and partner John Scribner advised on antitrust with counsel Michael Naughton. Partners Olivier Jauffret and Daneil Dokos supported on banking and finance in Paris and New York respectively.

NautaDutilh advised Sanofi on Belgian law matters.

Sanofi fought off stiff competition for Ablynx from Novo Nordisk, with the latter having turned to Davis Polk & Wardwell for support. Novo Nordisk’s offer was much lower at €2.6bn.

Linklaters advised the target Ablynx, acting as co-counsel with Goodwin Procter.

Magic circle corporate partners Arnaud Coibion and Philippe Remels advised Ablynx on Belgian law aspects of the deal from Brussels. They were supported by counsel Filip Lecoutre, who is based in Antwerp.

Goodwin advised on US law aspects, with life sciences chair Mitch Bloom leading the team for Ablynx from Boston.

The teal also included Boston corporate partners Jim Matarese and Blake Liggio, while Eubelius offered further support in Belgium.

The deal is expected to close in the second quarter of 2018.

Background to the deal

Unlike many of its pharmaceutical counterparts such as Pfizer, Novartis and Abbott, Sanofi has been quiet on the deals front in the past few years.

However, this represents its second major M&A deal in a week after its $12bn bid for Bioverativ. Weil Gotshal was Sanofi’s lead advisers on both deals. The firm also represented it on its acquisition of Genzyme for $20bn in 2011, sale of Merial, and acquisitions of Protein Sciences Corporation and Chattem.

Last year Abylnx raised $200 million in a US initial public offering, with Linklaters winning the role for the underwriters. Goodwin closed the deal in the US.