Kirkland & Ellis advised Bristol-Myers Squibb Co. in its all-cash $13.4 billion sale of Celgene Corp.’s psoriasis drug Otezla to Amgen Inc., which is being advised by Sullivan & Cromwell.

The deal comes as Bristol-Myers looks to win antitrust approval to complete its planned $74 billion acquisition of Celgene, which could amount to the largest merger in the pharmaceutical industry of the past decade.

Kirkland partners Daniel Wolf, Jonathan Davis and Ryan Brissette along with David Fox led its team on the deal. The transaction also included technology and IP transactions partner Lisa Samenfeld, tax partners Sara Zablotney and Dean Shulman, and antitrust partner Matt Reilly along with several associates.

Wolf, Davis, Brissette and Fox also led Kirkland’s deal team on Bristol-Myers Squibb’s $74 billion agreement to acquire Celgene, which was advised by Wachtell, Lipton, Rosen & Katz. Wachtell again advised Celgene in its sale of Otezla, with corporate partners Steven Cohen, David Lam and Edward Lee leading the team which also included antitrust partner Nelson Fitts and counsel Franco Castelli.

Sullivan & Cromwell took the lead advising Amgen on the deal. The firm has advised the biotechnology giant on numerous transactions over the years, including its $10.4 billion acquisition of Onyx Pharmaceuticals Inc. in 2013.

Leading Sullivan & Cromwell’s deal team are corporate partners Frank Aquila, Matthew Hurd, along with special counsel Anca Mihaela Paraian.

Executive compensation partner Heather Coleman, tax partner Ronald Creamer Jr., IP partner Nader Mousavi, Paris-based partner Olivier de Vilmorin and antitrust partners Renata Hesse and Michael Rosenthal also advised on the deal, along with several associates.

Arnold & Porter Kaye Scholer advised Bristol-Myers on antitrust and regulatory matters. Partners Debbie Feinstein, Daniel Kracov, and counsel Ewan Townsend led the team.

Despite a slowdown in M&A activity this year, Sullivan & Cromwell and Kirkland & Ellis have been dominating the deal tables.

Sullivan & Cromwell has advised on 103 deals worth over $383 billion thus far in 2019, according to Bloomberg data, while Kirkland has advised on 405 deals worth over $365 billion. Wachtell has advised on 46 deals worth over $506 billion.