Key Highlights
- Zymeworks (ZYME) has entered into a definitive agreement to acquire Theravance Biopharma (TBPH) in an all-cash transaction valued at $929 million
- The purchase price of $17 per share represents a 3.6% discount compared to Theravance’s previous closing price of $17.63
- The acquisition centers on Yupelri, an FDA-approved COPD medication that generated $266.6 million in U.S. net sales during 2025
- Shares of Theravance declined 2.8% in premarket activity, while Zymeworks shares dropped 1.4%
- Transaction completion is anticipated in the latter half of 2026, with expectations of positive impacts on Zymeworks’ earnings and cash generation
Zymeworks has entered into a definitive merger agreement to purchase Theravance Biopharma in an all-cash transaction totaling $929 million, offering $17 per share — representing a 3.6% markdown from Theravance’s Friday closing price of $17.63.
Investor reaction was tepid. Shares of Theravance Biopharma declined 2.8% to $17.14 during Monday’s premarket session. Zymeworks saw a 1.4% decline.
The below-market acquisition price is atypical and helps explain the negative market response. Buyout announcements generally include premiums above current trading levels.
That said, the offer does provide a 22% uplift compared to Theravance’s share price on March 3, when the company disclosed disappointing late-stage clinical trial results for ampreloxetine — a candidate therapy for a rare medical condition.
Following that clinical setback, Theravance implemented a significant reorganization that eliminated approximately 50% of its employee base. The company subsequently launched a strategic review process to evaluate options, including a potential sale.
Monday’s announcement brings that strategic evaluation to a conclusion.
Assets Included in the Transaction
The centerpiece of this acquisition is Yupelri, a once-daily nebulized COPD therapy that has already received FDA approval and is commercially available. This represents Theravance’s sole marketed pharmaceutical product.
Yupelri recorded $266.6 million in U.S. net sales throughout 2025, representing 12% growth versus 2024 figures. During the first quarter of 2026, U.S. net sales reached $62.4 million, marking a 7% year-over-year increase.
Theravance currently receives a 35% net profit share on U.S. Yupelri sales through its partnership with Viatris. According to Zymeworks, these royalties and profit-sharing arrangements currently produce approximately $60 million in annual cash flows.
This transaction marks a strategic pivot for Zymeworks — traditionally focused on oncology therapeutics — into the respiratory disease sector, where it will compete alongside pharmaceutical giants like GSK, AstraZeneca, and Boehringer Ingelheim.
Future of Ampreloxetine Program
The unsuccessful drug candidate remains part of the equation. Under the merger terms, Theravance shareholders will receive contingent value rights entitling them to 80% of any net proceeds should ampreloxetine be licensed, sold, or otherwise monetized within the next decade.
Zymeworks will retain the remaining 20% stake and has indicated it will explore opportunities to extract value from this asset.
Zymeworks anticipates the acquisition will enhance both earnings and cash flow metrics following completion, targeted for the second half of 2026.
The merger requires regulatory clearance and approval from Theravance shareholders.
Yupelri’s first quarter 2026 U.S. net sales of $62.4 million marked 7% growth compared to the prior year period.
Get 3 Free Stock Ebooks
Discover top-performing stocks in AI, Crypto, and Technology with expert analysis.
- Top 10 AI Stocks - Leading AI companies
- Top 10 Crypto Stocks - Blockchain leaders
- Top 10 Tech Stocks - Tech giants
