Zymeworks Inc. (Nasdaq: ZYME) completed its acquisition of Theravance Biopharma on September 23, adding commercial respiratory-drug revenue and additional royalty and milestone assets to its biotechnology portfolio.
According to the closing announcement, Theravance is now a wholly owned Zymeworks subsidiary. Theravance shareholders received $17 in cash for each ordinary share, together with one non-tradeable contingent value right.
The cash portion of the transaction was valued at approximately $929 million when the agreement was announced in June. The contingent rights could produce additional payments if Zymeworks licenses, sells or commercializes ampreloxetine, Theravance’s investigational treatment for symptomatic neurogenic orthostatic hypotension.
The principal acquired commercial asset is YUPELRI, or revefenacin, a once-daily nebulized long-acting muscarinic antagonist approved in the United States for maintenance treatment of chronic obstructive pulmonary disease. YUPELRI is commercialized through a collaboration with Viatris.
Theravance held a 35% share of YUPELRI’s U.S. net profits, along with rights to international royalties and additional commercial milestones. YUPELRI generated $70.7 million in second-quarter U.S. net sales, a 7% increase from the same period in 2025. Theravance’s implied 35% share of those sales was $24.7 million.
When the transaction was announced, CEO Kenneth Galbraith said Zymeworks was building “a more diversified and durable business by combining partner-driven cash flows and innovative R&D.”
Zymeworks financed part of the acquisition through $350 million in senior secured notes issued to an affiliate of OMERS Private Capital. The notes carry a fixed annual interest rate of 8.25% and mature on December 31, 2036.
The debt is issued by indirect Zymeworks subsidiaries and secured by Theravance-related entities and assets. Under the original financing structure, 75% of the acquired YUPELRI profit-share cash flows were assigned to service the notes. That arrangement limits recourse to the wider Zymeworks business but reduces the portion of near-term YUPELRI cash flow available to the parent company.
The original funding plan also contemplated using Theravance’s estimated cash balance at closing and approximately $219 million of Zymeworks’ cash. Zymeworks has not yet released complete post-closing or pro forma financial statements.
Theravance brought other potential financial assets to the combined company. These include a possible $100 million payment linked to 2026 sales of GSK’s TRELEGY ELLIPTA, additional YUPELRI milestones and royalty interests involving other products. Receipt of those payments remains dependent on commercial thresholds and contractual conditions.
Zymeworks reported $322.5 million in cash, cash equivalents and marketable securities as of June 30, 2026. Second-quarter revenue was $4.6 million, while the company recorded a $45 million net loss. Its financial position subsequently benefited from a $250 million milestone earned after the August FDA approval of an additional Ziihera treatment indication.
The acquisition gives Zymeworks a broader revenue base, but its financial benefit will depend on YUPELRI sales, integration costs, debt servicing, future milestones and management’s ability to control expenses. Zymeworks will discuss the final transaction details during an investor call scheduled for September 28.
Upcoming Catalysts
- Zymeworks’ acquisition-update conference call on September 28
- Filing of required pro forma financial information
- Future YUPELRI sales and profit-share results
- A possible $100 million TRELEGY-related milestone
- Decisions concerning the acquired ampreloxetine program
- Additional Ziihera regulatory milestones and royalty growth
- Integration and restructuring updates
Sources
- Zymeworks completes the Theravance acquisition — September 23, 2026
- Zymeworks acquisition-closing Form 8-K — SEC, September 23, 2026
- Original Zymeworks–Theravance transaction announcement — June 29, 2026
- Zymeworks second-quarter 2026 financial results
- Theravance second-quarter 2026 financial results
- Zymeworks announces Ziihera approval and $250M milestone — August 25, 2026
Editorial Disclosure
This article is based entirely on publicly available information, including company announcements and SEC filings. Securities discussed or referenced include Zymeworks Inc. (Nasdaq: ZYME) and the former ordinary shares of Theravance Biopharma Inc. (previously Nasdaq: TBPH). Biotech Stocks Daily has not received compensation from Zymeworks, Theravance Biopharma, their management, investor relations representatives or any third party for this specific article. Biotech Stocks Daily may have current or past paid business relationships with other companies, which do not influence the content or conclusions of this article. No staff member or principal of Biotech Stocks Daily holds a position in any security mentioned at the time of publication.
Confirmed sources include Zymeworks’ September 23, 2026 closing announcement and Form 8-K, the original June 29 transaction announcement, both companies’ second-quarter financial disclosures and Zymeworks’ August 25 Ziihera announcement. Estimates concerning future revenue, cash flow, milestones, integration benefits and transaction economics originated from company management and have not been independently validated by Biotech Stocks Daily.
Completion of the acquisition does not guarantee that the anticipated financial benefits will be realized. YUPELRI sales may decline or grow more slowly than expected, while integration, restructuring and financing costs may exceed current estimates. Milestone and royalty payments involving YUPELRI, TRELEGY, Ziihera, ampreloxetine and other assets remain dependent on commercial, clinical, regulatory or contractual conditions.
Zymeworks reported continued operating losses before the acquisition. The transaction introduced $350 million in senior secured debt bearing interest at 8.25% annually, and the acquired assets and subsidiaries are subject to security interests and operating restrictions. The contingent value rights issued to former Theravance shareholders are speculative, non-tradeable and may never produce a payment. Complete post-closing financial statements and pro forma results were not available when this article was prepared.
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