TLDR
- Zymeworks agreed to buy Theravance Biopharma for $929 million, or $17 per share in cash
- The deal price is a 3.6% discount to Theravance’s last closing price of $17.63
- Theravance’s only marketed drug is Yupelri, an FDA-approved COPD treatment with $266.6 million in U.S. net sales in 2025
- Theravance stock slipped 2.8% in premarket trading; Zymeworks fell 1.4%
- The deal is expected to close in the second half of 2026 and be accretive to Zymeworks earnings and cash flow
Zymeworks has agreed to acquire Theravance Biopharma in a $929 million all-cash deal, paying $17 per share — a 3.6% discount to Theravance’s Friday close of $17.63.
The market wasn’t impressed. Theravance stock fell 2.8% to $17.14 in premarket trading Monday. Zymeworks dropped 1.4%.
The discount is unusual for an acquisition and explains why investors pushed the stock lower rather than higher. Typically buyout deals carry a premium.
However, the deal does represent a 22% premium to where Theravance was trading on March 3, the day it reported a late-stage trial failure for ampreloxetine — a drug being developed for a rare disorder.
That failed trial triggered a restructuring at Theravance, which included cutting roughly half its workforce. The company then began exploring strategic alternatives, including a sale.
With Monday’s announcement, that process is now considered complete.
What Zymeworks Gets
The main asset is Yupelri, a once-daily nebulized treatment for COPD that’s already on the market. It’s the only commercial product Theravance currently has.
Yupelri generated $266.6 million in U.S. net sales in 2025, up 12% from 2024. In the first quarter of 2026, U.S. net sales came in at $62.4 million, up 7% year-over-year.
Theravance holds a 35% net profit share on Yupelri in the U.S., where it’s marketed through a collaboration with Viatris. Zymeworks says those royalties and profit share currently generate around $60 million in annualized cash flows.
The deal moves Zymeworks — an oncology-focused company — into the respiratory space, putting it in the same market as GSK, AstraZeneca, and Boehringer Ingelheim.
What Happens to Ampreloxetine
The failed drug doesn’t disappear entirely. As part of the deal, Theravance stockholders will receive contingent value rights giving them 80% of any net proceeds from a future license, sale, or other deal involving ampreloxetine over the next 10 years.
Zymeworks keeps the remaining 20% and has said it will consider ways to monetize the asset.
Zymeworks expects the transaction to be accretive to earnings and cash flow once it closes, which is expected in the second half of 2026.
The deal is subject to regulatory approval and a vote from Theravance stockholders.
Yupelri’s first quarter 2026 U.S. net sales of $62.4 million represented 7% growth versus the same period last year.
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