Zymeworks Expands Into Respiratory Market WithTheravance Buyout

Oncology-focused drugmaker Zymeworks (NASDAQ:ZYME) has agreed to acquire Theravance Biopharma (NASDAQ:TBPH) for US$929 million in cash, expanding its portfolio into the highly competitive respiratory segment.

The acquisition delivers Zymeworks a 35 percent US net profit share in Yupelri, the first and only FDA-approved once-daily nebulized treatment for chronic obstructive pulmonary disease (COPD).

Theravance markets the drug in the US through a partnership with Viatris (NASDAQ:VTRS).

Yupelri generated US$266.6 million in US net sales in 2025, a 12 percent year-over-year increase, and posted $62.4 million in the first quarter of 2026.

The deal positions Zymeworks against pharmaceutical giants such as GSK (NYSE:GSK) and AstraZeneca (NASDAQ:AZN), which historically dominate the global respiratory market.

However, Zymeworks management maintained that the deal was not as a pivot from oncology, but as a strategic financial maneuver to establish a self-sustaining capital allocation model.

“We are building a more diversified and durable business by combining partner-driven cash flows and innovative R&D, together in an integrated strategic approach to build long-term stockholder value,” Zymeworks Chair and CEO Kenneth Galbraith said.

“Upon closing, this acquisition meaningfully expands and diversifies future revenue sources for our partnered product portfolio, with an expected near-term impact on commercial royalty revenue.”

Meanwhile, the buyout provides a soft landing for Theravance, which announced in March it was exploring alternatives after its experimental blood pressure drug, ampreloxetine, failed a late-stage trial.

Following that failure, Theravance shut down its research and development division and cut its workforce by half, leaving Yupelri and Trelegy Ellipta as its primary revenue drivers.

Zymeworks stated it intends to complete Theravance’s organizational restructuring upon closing while maintaining the company’s existing hospital promotion infrastructure.

Furthermore, the company said it will consider monetizing Theravance’s remaining acquired assets, including ampreloxetine. Any proceeds from a future ampreloxetine divestment or licensing deal will be split 20 percent to Zymeworks and 80 percent to Theravance shareholders.

Following the Monday (June 29) announcement, Theravance shares slipped 3.5 percent in morning trading, while Zymeworks dropped more than 8 percent.

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Securities Disclosure: I, Giann Liguid, hold no direct investment interest in any company mentioned in this article.