Dealmaking accelerated across the biotech and pharma landscape this week, with two acquisitions targeting commercial-stage respiratory and oncology assets.

Zymeworks to acquire Theravance

Zymeworks Inc. entered into a definitive agreement to acquire Theravance Biopharma, Inc. for $17.00 per share in cash, representing a total transaction value of approximately $929 million. The deal is expected to close in the second half of 2026, pending regulatory and Theravance Biopharma shareholder approval.¹

The acquisition centers on Yupelri (revefenacin), the only approved nebulized, once-daily long-acting muscarinic antagonist (LAMA) for the maintenance treatment of chronic obstructive pulmonary disease.¹ Yupelri has been marketed in the U.S. since 2019 through a collaboration between Viatris Inc. and Theravance Biopharma.

Per the terms of the acquisition, Zymeworks will receive access to a 35% U.S. net profit share in Yupelri, while Theravance Biopharma will remain eligible to receive up to $125 million in commercial milestone payments from Viatris tied to U.S. net sales, along with double-digit tiered royalties and additional milestones on ex-U.S. sales.¹

Beyond Yupelri, the deal brings additional near-term cash flows with a $100 million milestone payment from Royalty Pharma expected in Q1 2027 related to global net sales of Trelegy Ellipta by GSK.¹ Theravance Biopharma is also eligible to receive up to approximately 20% royalty on net sales of Vibativ (telavancin) from Cumberland. Zymeworks is also expected to retain approximately $2.5 billion in Irish tax attributes accumulated by Theravance Biopharma.

For the R&D pipeline, Zymeworks will explore licensing, divesting or otherwise monetizing ampreloxetine within one year of closing, with economics split 20/80 between Zymeworks and Theravance Biopharma shareholders.¹

"The acquisition of Theravance Biopharma represents successful execution of one of the key strategic priorities we outlined earlier this year," said Kenneth Galbraith, Chair and Chief Executive Officer of Zymeworks. "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."

Upon closing, Zymeworks intends to complete Theravance Biopharma's previously announced organizational restructuring to align resources with Yupelri’s commercial focus, which is expected to significantly reduce R&D and G&A costs.¹ The company also intends to substantially preserve Theravance Biopharma's existing hospital promotion infrastructure.

Ipsen to Acquire Kartos Therapeutics

Ipsen entered into a definitive merger agreement to acquire Kartos Therapeutics, adding navtemadlin, an investigational MDM2 inhibitor, to its late-stage oncology pipeline.

Under the terms of the agreement, Ipsen is set to pay $450 million upfront at closing through a fully-owned subsidiary.² Kartos shareholders are expected to be eligible to receive upwards of an additional $1.3 billion in milestone payments, including a significant regulatory approval milestone and sales-based milestones.² The transaction is expected to close by the end of Q3 2026 and is anticipated to be accretive to Ipsen's core operating income from 2029, with limited dilution to 2026 full-year guidance.

Navtemadlin is designed to restore the natural tumor-suppressing function of p53 by inhibiting MDM2, a critical tumor suppressor pathway implicated in myelofibrosis. The drug is currently being evaluated in Poiesis, a global Phase III trial enrolling more than 600 patients across more than 250 sites as an add-on to standard-of-care ruxolitinib in patients with intermediate and high-risk TP53 wild-type myelofibrosis who have a suboptimal response to ruxolitinib, a population with a median overall survival of approximately one to two years following treatment discontinuation.²

Earlier Phase Ib/II data presented at the European Hematology Association Congress in 2023 showed that, at Week 24, 42% of patients with a suboptimal response to ruxolitinib achieved at least a 25% reduction in spleen volume, 32% achieved at least a 35% reduction in spleen volume, and 32% achieved a total symptom score improvement of at least 50%.² The data also suggested disease modification potential, as 71% of evaluable patients achieved a 20% or greater reduction in driver variant allele frequency, and 57% showed an improvement in bone marrow fibrosis of at least one grade by central review.²

"This acquisition further strengthens our late-stage oncology pipeline and reflects our continued focus on bringing transformational treatments to people living with cancer," said David Loew, CEO, Ipsen. "We are excited by the potential of navtemadlin to define a new treatment paradigm for patients with myelofibrosis who have a suboptimal response to current standard of care, addressing a critical care gap and offering the potential for a new therapeutic option as early as 2028."

Sources

1. Zymeworks to Acquire Theravance Biopharma, Inc. Zymeworks Inc. June 29, 2026 https://www.globenewswire.com/news-release/2026/06/29/3318760/0/en/zymeworks-to-acquire-theravance-biopharma-inc.html
2. Ipsen to acquire Kartos Therapeutics, expanding hemato-oncology late-stage pipeline Ipsen Junne 29, 2026 https://www.globenewswire.com/news-release/2026/06/29/3318643/0/en/ipsen-to-acquire-kartos-therapeutics-expanding-hemato-oncology-late-stage-pipeline.html