aibioGyre Therapeutics completes all-stock acquisition of Cullgen valued at about $300 million
Tickers GYRE
Gyre closed its merger with Cullgen on May 4, 2026. Cullgen holders get Gyre common and Series B preferred stock, and Cullgen's former CEO Ying Luo becomes Gyre's CEO.
Key facts
- Company
- Gyre Therapeutics, Inc. (NASDAQ: GYRE)
- News type
- Mergers
- Primary source
- GYRE THERAPEUTICS, INC. Form 8-K filed May 4, 2026 (SEC EDGAR)
Gyre Therapeutics, Inc. (Nasdaq: GYRE) completed its acquisition of Cullgen Inc. on May 4, 2026, in an all-stock transaction that valued Cullgen at approximately $300 million. The company reported the closing in a Form 8-K filed May 4, 2026. The deal also changed the company's top management.
What the merger agreement provides
Under the Agreement and Plan of Merger and Reorganization dated March 2, 2026, a Gyre subsidiary, Helix Merger Sub Corp., merged into Cullgen. Cullgen survives as a wholly owned subsidiary of Gyre. The filing says the merger is intended to qualify as a tax-free reorganization for federal income tax purposes.
Cullgen shareholders receive stock, not cash. Shares held by certain designated holders convert into Gyre Series B Convertible Preferred Stock, at an Exchange Ratio of 0.4753 divided by five for each share of Cullgen common stock. Other holders receive Gyre common stock at the Exchange Ratio. Each share of the new preferred stock is convertible into five shares of Gyre common stock, subject to conditions tied to a shareholder vote.
The filing says Gyre will not issue more than 19.99% of its issued and outstanding common stock or voting power before that vote. Gyre filed its definitive proxy statement on April 27, 2026 and will hold the stockholder meeting on June 10, 2026 to vote on converting the preferred stock into common stock in accordance with certain Nasdaq rules.
In-the-money Cullgen stock options became options to purchase Gyre common stock on their existing terms. Other options were cancelled for no consideration. Cullgen restricted stock units vested and were settled for Cullgen common stock, then exchanged for Gyre common stock.
Common control and accounting
Gyre and Cullgen were controlled by the same parent, GNI Group Ltd., a company incorporated under the laws of Japan, both before and after the merger. Gyre therefore treats the deal as a combination of entities under common control rather than a business combination. It will record Cullgen's assets and liabilities at their historical carrying amounts and adjust its financial statements to reflect the combination as if it had occurred at the beginning of the earliest period presented.
Terms of the preferred stock
Holders of the preferred stock are entitled to dividends on an as-if-converted basis, in the same form as dividends paid on common stock. The preferred stock carries one vote on all matters submitted to stockholders, subject to certain limitations, and has no preference on liquidation, dissolution or winding-up. After stockholder approval, a holder may convert into common stock, but may not convert if the holder and its affiliates would then beneficially own more than a specified percentage, set by the holder between 0% and 19.99%.
Board and management changes
Thomas Eastling and Songjiang Ma resigned from Gyre's board immediately before the merger took effect, and Mr. Ma also resigned as President. The filing says the resignations were not the result of any disagreements with the company. The board now has seven directors.
Ying Luo, Ph.D., Cullgen's former Chief Executive Officer, became Gyre's Chief Executive Officer and President and a Class I director. Dr. Luo also chairs the Nominating and Corporate Governance Committee, with Dan Weng and Gordon Carmichael as the other members. Ping Zhang, the former Interim Chief Executive Officer and Executive Chairman, stays on as Chairman of the Board. Thomas Eastling was appointed Chief Financial Officer, succeeding Ruoyu Chen, who resigned from that position.
About the company
Gyre's press release describes it as a commercial-stage biopharmaceutical company focused on fibrosis. Its subsidiary, Gyre Pharmaceuticals Co., Ltd., sells ETUARY (pirfenidone capsule) in China. As of December 31, 2025, Gyre Therapeutics owned a 69.7% equity interest in Gyre Pharmaceuticals. Cullgen is a clinical-stage company developing targeted protein degrader and degrader antibody conjugate therapies.
Moelis & Company LLC acted as financial advisor to the special committee of Gyre's board. Gibson, Dunn & Crutcher LLP is Gyre's legal counsel, and Mintz, Levin, Cohn, Ferris, Glovsky & Popeo, P.C. is counsel to Cullgen.