Gyre Therapeutics Acquires Cullgen for $300M to Expand Protein Degradation Platform
Key Insights
Gyre Therapeutics announced a $300 million all-stock acquisition of Cullgen Inc (search)., creating a fully integrated U.S.-China biopharmaceutical company with targeted protein degradation capabilities.
The combined entity will leverage Cullgen's protein degrader pipeline, including CG001419 for acute pain and CG009301 for blood cancers, alongside Gyre's commercial fibrosis treatments.
Gyre plans to submit a New Drug Application for Hydronidone liver fibrosis (search) treatment in the first half of 2026 following regulatory support for conditional approval.
Gyre Therapeutics announced its agreement to acquire Cullgen Inc (search). in an all-stock transaction valued at approximately $300 million, creating a fully integrated biopharmaceutical company with capabilities spanning from discovery to commercialization across the United States and China. The acquisition combines Gyre's commercial-stage fibrosis treatments with Cullgen's targeted protein degradation platform and clinical pipeline.
Strategic Combination Creates Integrated Platform
The transaction will establish a comprehensive biopharmaceutical operation covering multiple therapeutic areas including inflammatory diseases, cancers, and pain management. Under the definitive agreement, Cullgen will become a wholly owned subsidiary of Gyre, with the transaction expected to close early in the second quarter of 2026.
Dr. Ying Luo, current CEO of Cullgen and expected President and CEO of the combined entity, emphasized the strategic synergies: "Cullgen brings strong drug discovery capabilities and a solid preclinical and clinical pipeline to complement Gyre's existing and highly efficient China-based manufacturing capabilities and sales team."
The combined company will benefit from Gyre's established commercial presence in China, where its flagship product ETUARY® (pirfenidone capsule) generated $105.8 million in net sales in 2024 as the first approved treatment for idiopathic pulmonary fibrosis (search) in the People's Republic of China since 2011.
Cullgen's Protein Degradation Pipeline
Cullgen contributes a portfolio of targeted protein degrader candidates designed to eliminate therapeutically relevant proteins with enhanced selectivity and improved therapeutic profiles. The company's lead product candidate, CG001419, is an oral pan-tropomyosin receptor kinase (search) (TRK) degrader that completed a Phase 1 trial for acute post-operative pain with positive top-line results released in late 2025.
Following recent IND submission, Cullgen expects to initiate a Phase 2 trial in acute pain in bunionectomy patients in the United States, pending FDA allowance. CG001419 is also being evaluated in a Phase 1 trial for solid tumor treatment.
The company's second product candidate, CG009301, represents a GSPT1 (search) degrader currently in Phase 1 trials for blood cancers, including relapsed/refractory acute myeloid leukemia (search), higher-risk myelodysplastic syndrome (search), and acute lymphoblastic leukemia (search). Cullgen is also advancing preclinical programs featuring next-generation degrader-antibody conjugates (DACs).
Regulatory Progress for Hydronidone
Gyre's near-term regulatory milestone centers on Hydronidone (F351), a structural analogue of pirfenidone that demonstrated statistically significant fibrosis regression after 52 weeks of treatment in a pivotal Phase 3 clinical trial for chronic hepatitis B (search)-associated liver fibrosis (search). The compound received Breakthrough Therapy designation from China's Center for Drug Evaluation in March 2021.
Following a pre-NDA meeting with China's National Medical Products Administration, Gyre received support for conditional approval and priority review eligibility. Ping Zhang, Executive Chairman of Gyre, stated: "Gyre Pharmaceuticals (search) plans to submit an NDA for Hydronidone for conditional approval in the first half of 2026 and conduct a Phase 3c confirmatory trial to support full approval in China."
Leadership Structure and Global Expansion
Upon completion of the acquisition, Ping Zhang will remain as Executive Chairman, while Dr. Ying Luo will serve as President and CEO and join the board of directors. The leadership structure is designed to support global expansion, with Gyre exploring development of Hydronidone in ex-China territories.
The combined entity will maintain operations across both countries, leveraging China-based manufacturing and sales capabilities alongside U.S. clinical development expertise. Gyre currently owns a 69.7% equity interest in Gyre Pharmaceuticals (search) as of the third quarter of 2025.
Expanded Therapeutic Portfolio
Beyond the core fibrosis and protein degradation programs, the combined company will advance treatments across multiple indications. Gyre Pharmaceuticals (search) is developing therapies for Parkinson's disease, radiation-induced lung injury, chronic obstructive pulmonary disease, pulmonary arterial hypertension, and acute liver failure, while also pursuing therapeutic expansions of ETUARY and development programs for compounds F573, F528, and F230.
The transaction requires customary closing conditions, including necessary regulatory approvals in the United States. Prior to this agreement, Cullgen's proposed merger with Pulmatrix was terminated.