Theravance Biopharma adds proxy disclosures amid Zymeworks merger litigation

Theravance Biopharma filed an 8-K on September 10, 2026 disclosing supplemental information to its definitive merger proxy statement, following litigation and demand letters from purported shareholders. The company had entered a merger agreement on June 28, 2026 with Zymeworks Inc. and its merger subsidiary, under which Theravance would become a wholly owned subsidiary of Zymeworks.¹ Theravance filed its definitive proxy statement on August 21, 2026 for an extraordinary general meeting scheduled for September 18, 2026 at 1:30 p.m. Pacific Time to vote on the merger.¹

As of September 10, 2026, the company said it was aware of three complaints filed as individual shareholder actions related to the merger, against the company, its board members, and in one case Zymeworks.¹ The complaints seek to enjoin the merger unless certain allegedly omitted material information is disclosed, and seek rescission or damages if the deal closes.¹ The company also said it had received thirteen demand letters from law firms representing purported shareholders alleging similar disclosure deficiencies.¹

Theravance and other named defendants denied the allegations and said they believed the claims were without merit, but said they chose to voluntarily supplement the proxy to limit litigation costs and potential delay to the merger.¹

Among the added disclosures, Lazard's financial analysis implied an equity value range of $15.25 to $16.25 per ordinary share, based on roughly 54.9 million fully diluted shares and net debt of about $(385) million as of June 30, 2026.¹ The filing also detailed the sale process, noting that after a December 10, 2025 board meeting, Lazard contacted 60 potential counterparties, of which 20, including Zymeworks, signed confidentiality agreements.¹ Evercore's engagement letter was separately amended on June 16, 2026 to provide a $7 million fee payable upon the merger's completion.¹