ThalassaX Therapeutics United States Ltd today announced that the first patient has been successfully dosed in the U.S. Phase I clinical trial of CS231295, a next-generation brain-penetrant Aurora B Kinase selective inhibitor independently discovered and developed using the company's core AI-powered + Chemogenomic technology platform.
This study is an open-label, dose-escalation Phase I clinical trial in patients with advanced solid tumors, designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of CS231295.
Dr. Xianping Lu, Chairman of ThalassaX Therapeutics United States Ltd, commented:
"The first patient in the U.S. has successfully received the initial dose of CS231295. We are grateful to the patients and clinical sites for their support. From the outset, the global development strategy for CS231295 has centered on parallel Sino‑U.S. IND submissions, targeting two of the most challenging solid-tumor settings: RB1‑deficient cancers and brain metastases. Launching clinical development in the United States—one of the world’s core markets for innovative oncology therapeutics—marks a milestone of deep strategic significance for our team.”
He added that the company will continue to uphold rigorous scientific standards and advance each subsequent study with discipline and precision, generating robust clinical evidence that honors our commitments to patients and to science.
Malignant brain tumors and brain metastases remain among the most challenging settings in oncology. CS231295 was designed to address this unmet need through precise inhibition of tumor‑specific Aurora B overexpression, inducing synthetic lethality in genetically vulnerable tumors such as those with RB1 deficiency.
The molecule’s favorable blood–brain barrier penetration provides a meaningful therapeutic advantage for primary brain tumors and brain metastases. In addition, CS231295 demonstrates broad antitumor activity, including anti‑angiogenic effects and modulation of the tumor microenvironment, and shows potential for synergistic combinations with chemotherapy, targeted therapies, and immuno‑oncology agents.
Preclinical studies have shown potent pharmacodynamic activity, favorable pharmacokinetics, and a good safety profile. No drug candidate with a similar design has yet entered global clinical trials.
CS231295 received IND approval from China’s NMPA in December 2024, with first‑in‑human dosing in China in May 2025. The program achieved FDA IND clearance in July 2025, enabling parallel Sino‑U.S. development. The first U.S. patient dosing marks another major step toward accelerating global clinical progress and informing subsequent study designs.
About ThalassaX Therapeutics United States Ltd
ThalassaX Therapeutics United States Ltd, a wholly-owned subsidiary of Chipscreen Biosciences, was established on October 16, 2020 and is headquartered in New Jersey, USA. Upholding the philosophy of "Constant Innovation for Life," the company leverages Chipscreen’s AI-assisted design and chemogenomics technology platforms to integrate early R&D in China with international multi‑center clinical resources, driving global development of CS231295 and other innovative therapeutics for areas of high unmet medical need.
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The first patient in the U.S. has successfully received the initial dose of CS231295. We are grateful to the patients and clinical sites for their support.
