CStone and Kimia Therapeutics Enter Clinical Development Collaboration to Advance a Novel Drug Candidate Targeting Repair Pathways Critical for Solid Tumor Survival

SUZHOU, China, Nov. 3, 2026 — CStone Pharmaceuticals ("CStone," HKEX: 2616), an innovation-driven biopharmaceutical company focused on the research and development of therapies for oncology, immunology, inflammation, and other key disease areas, today announced that it has entered into a clinical collaboration agreement with Kimia Therapeutics, Inc. ("Kimia"), a biopharmaceutical company developing innovative therapeutics for oncology and immunology, to advance the clinical development of a potential first-in-class asset targeting the DNA damage response (DDR) pathway critical for solid tumor cell survival, with CStone leading the clinical development in mainland China and Australia. The collaboration further underscores the international recognition of CStone's proven clinical development and regulatory expertise and advances the Company's strategy of disciplined external innovation and global expansion. It also creates a clear pathway for CStone to participate in the global commercial value of a first-in-class asset through milestone payments and royalties. Kimia, based in Berkeley, California, is advancing small-molecule medicines with its integrated ATLAS platform, a transformative approach to AI-driven drug discovery. Kimia is a portfolio company of The Column Group (TCG), a leading life sciences investment firm focused on building and investing in biotechnology companies from early-stage scientific innovation through clinical development and strategic transactions.

Key highlights of the collaboration

- Proven development expertise and global regulatory reach: the collaboration pairs CStone's proven oncology clinical development and regulatory expertise across multiple markets — demonstrated by four approved innovative drugs and 21 new drug application approvals across nine indications — with Kimia's AI-enabled drug discovery approach, underpinned by its proprietary ATLAS platform combining nanogram-scale parallel synthesis, direct-to-biology screening, and machine learning.

- Targeting high-unmet-need patient populations: the planned Phase I study includes dose-escalation and expansion components to evaluate the asset in biomarker selected patient populations as an initial proof-of-concept to define safety, pharmacokinetics, pharmacodynamics and early activity.

- Long-term value creation: the collaboration also establishes a scalable framework that may be extended to other promising assets over time, creating a repeatable model for CStone to contribute its clinical development expertise to advancing innovative therapies, generate value through milestone payments and royalties, and expand its international development footprint.

Collaboration overview

Under the collaboration, CStone will lead the Phase I clinical development of the asset in mainland China and Australia, applying its full-spectrum oncology clinical development and regulatory capabilities. Kimia will contribute the clinical supply of the asset, along with scientific guidance, product-related regulatory oversight and other agreed development support — reflecting a co-development model built on each party's complementary strengths.

Under the agreement, Kimia will reimburse CStone for the applicable clinical development costs. CStone is eligible to receive milestone payments plus royalties on global net sales of the asset during the applicable royalty term, in accordance with the agreement.

Dr. Jason Yang, Chief Executive Officer, President of R&D and Executive Director of CStone, commented: "We are pleased to collaborate with Kimia to advance this innovative, first-in-class oncology asset. This collaboration establishes a scalable framework with the potential to support additional programs with Kimia and other TCG portfolio companies, connecting promising innovation with a clear path to efficient and robust clinical development. In addition, the deal structure aligns our shared commitment to the Asset's development and long-term success, while providing CStone with the opportunity to participate in the value it creates globally. We see this repeatable model as an important avenue to broaden our participation in global innovation and create long-term value for our shareholders."

Stig Hansen, CEO of Kimia Therapeutics, commented: "We are delighted to work with CStone to advance the clinical development of this potential first-in-class asset that was discovered by Kimia leveraging AI and med chem integration. CStone's expertise in oncology clinical development will be valuable as we evaluate our lead asset in phase I proof-of-concept studies in bio-marker selected patient populations and generate the clinical evidence needed to guide its further development. CStone's clinical development capabilities complement Kimia's technology-driven drug discovery platform, and we look forward to working collaboratively to advance the program."

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SOURCE CStone Pharmaceuticals