Kirkland & Ellis, Matheson, Arthur Cox, Skadden, Sidley Austin, Maples Group, and Davies Ward Phillips & Vineberg advised on Zymeworks Inc.‘s acquisition of Theravance Biopharma, Inc. for US$17.00 per share in cash, representing an equity value of approximately US$929 million.

Under the terms of the transaction, Zymeworks will acquire all outstanding equity of Theravance Biopharma. Theravance shareholders will also be entitled to receive a contingent value right entitling them to 80% of the net proceeds from any future licence, divestiture, or other monetisation of ampreloxetine over the next ten years.

The acquisition adds YUPELRI, the first and only nebulized, once-daily, long-acting muscarinic antagonist for the maintenance treatment of chronic obstructive pulmonary disease, together with additional royalty interests, milestone payments and a preclinical immunology and inflammation portfolio, to Zymeworks’ partnered portfolio.

The transaction is expected to close in the second half of 2026, subject to shareholder and regulatory approvals.

Kirkland & Ellis acted as legal counsel to Zymeworks Inc.

The Kirkland team included corporate lawyers Rachael Coffey, Dan Li, Graham Robinson, Lara Pillay, Cameron Smith, Scott Kim and Hailey Brenner; debt finance lawyers Darren Littlejohn, Rachael Lichtman, Lillian Xiao and Katie Schneller; technology & IP transactions lawyers Shellie Freedman, Amber Harezlak and Michael Johnston; executive compensation lawyers Timothy Nelson and Annie Gritter; tax lawyers Liam Murphy and Daniel Henry; employee benefits lawyers Justin Coddington and Stew Dunoskovic; employment & labor lawyers Kayla Garcia and Kaitlyn Hodgman; antitrust & competition lawyers Maria Raptis and Daniel Rosenthal; ex-US antitrust lawyers Thomas Sebastian Wilson and Margarita Karkantzou; and capital markets lawyers Ross Leff and Basit Bangash.

Matheson acted as Irish tax counsel to Zymeworks Inc., working alongside Kirkland & Ellis.

The cross-departmental Matheson team was led by Tax partners Gerry Thornton and Philip Tully, Corporate M&A partners David Jones and Brian Butterwick and Finance and Capital Markets partner Maireadh Dale, with support from Employment partner Rachel Barry.

Arthur Cox advised Theravance Biopharma, Inc.

The Arthur Cox team advising Theravance Biopharma was led by Ailish Finnerty and Orlaith Kane (Tax) and David Vos (Corporate and M&A) and included Andrea Bowdren and Aisling Taylor (Corporate and M&A); Cristina Susanu (Tax); Kevin Langford and Melissa O’Sullivan (Employment); and Richard Ryan and Emily Tyler (Competition and Regulated Markets).

Sidley Austin LLP is serving as legal counsel to OMERS Life Sciences. Maples and Calder (Ireland) LLP and Davies Ward Phillips & Vineberg LLP provided Irish legal counsel and tax counsel, respectively, to OMERS Life Sciences.