Zymeworks will spend nearly $1 billion to acquire biotech company Theravance, picking up an approved lung disease drug and several royalty contracts, according to a June 29 announcement. The acquisition, valued at $929 million, will expand Zymeworks' portfolio with both marketed and investigational assets as the Vancouver-based company continues its shift toward a royalty-driven business model.
The centerpiece of the deal is Yupelri, a long-acting muscarinic antagonist approved in 2019 for chronic obstructive pulmonary disease. Theravance currently markets Yupelri with Viatris, which provides Zymeworks with a 35% share of U.S. net profits. In 2025, the therapy generated $266.6 million in sales—an increase of 12% over the previous year—and comes with eligibility for up to $125 million in commercial milestone payments based on certain U.S. sales targets as well as ongoing royalties.
In addition to Yupelri, Zymeworks will gain rights from Theravance's agreement with Royalty Pharma that includes expected milestone payments of $100 million in early 2027 tied to global net sales of GSK’s COPD and asthma inhaler Trelegy Ellipta. Another deal previously made by Theravance with Cumberland grants Zymeworks a 20% royalty on net sales of Vibativ, an antibacterial therapy.
Zymeworks will also acquire several investigational assets from Theravance; however, their future remains uncertain as they "will be evaluated in the context of the Company’s broader pipeline and capital allocation framework." The possibility exists that some programs could be sold off or licensed out during closing review processes. One such asset is ampreloxetine—a neurodegenerative disease drug—which failed its Phase 3 CYPRESS trial earlier this year but may still be subject to licensing discussions before deal completion.
Theravance shareholders are set to receive a contingent value right entitling them to 80% of any net proceeds from ampreloxetine if monetized after closing. Additionally, Zymeworks gains access to approximately $2.5 billion in Irish tax attributes held by Theravance for potential future use.
Theravance had announced plans in March to wind down research and development operations following clinical setbacks including multiple program failures and layoffs over recent years—a process culminating after comprehensive strategic review ahead of this transaction.
