Shares of Theravance Biopharma were sliding in premarket trading Monday after larger biotech Zymeworks agreed to acquire the company for roughly $929 million.

Under the terms of the deal, Zymeworks will pay $17 a share in cash for Theravance, representing 3.6% discount to Friday's closing price of $17.63 but a 22% premium to its closing price on March 3, after the company reported a late-stage trial failure for its drug candidate, ampreloxetine.

Investors weren't cheering the acquisition. Theravance stock slipped 2.8% to $17.14 in Monday's premarket session, while Zymeworks headed 1.4% lower.

While the price tag might explain the market's cool reaction, the deal is equally consequential for Zymeworks as it absorbs a company already under pressure.

Theravance has one drug, a treatment for chronic obstructive pulmonary disease called Yupelri, currently on the market. The recent trial failure for ampreloxetine prompted the company to accelerate a review of strategic alternatives and launch a restructuring plan, which included slashing half of its workforce.

With the acquisition, slated to close in the second half of the year, that process will be considered complete, Theravance said on Monday.

In addition to the cash consideration, Theravance shareholders will receive contingent value rights entitling them to 80% of net proceeds from any future license, divestiture or other monetization of ampreloxetine within the next 10 years.

Zymeworks expects the transaction "to be accretive to earnings and cash flow upon closing," citing Yupelri's U.S. profit share and global royalties, which currently generate annualized cash flows of $60 million.

Write to Mackenzie Tatananni at mackenzie.tatananni@barrons.com

This content was created by Barron's, which is operated by Dow Jones & Co. Barron's is published independently from Dow Jones Newswires and The Wall Street Journal.

(END) Dow Jones Newswires

June 29, 2026 07:26 ET (11:26 GMT)

Copyright (c) 2026 Dow Jones & Company, Inc.