ThalassaX Therapeutics doses first patient in U.S. Phase I trial of CS231295
Saturday, July 18, 2026
ThalassaX Therapeutics United States Ltd has announced that the first patient has been dosed in its U.S. Phase I clinical trial of CS231295, a brain-penetrant Aurora B kinase selective inhibitor developed using the company's AI-powered chemogenomic technology platform.
The open-label, dose-escalation Phase I study is evaluating the safety, tolerability, pharmacokinetics and preliminary anti-tumour activity of CS231295 in patients with advanced solid tumours.
The company said the U.S. trial is part of its global development strategy, which includes parallel investigational new drug (IND) programmes in China and the United States. The programme is focused on treating two difficult cancer types: RB1-deficient tumours and brain metastases. The first patient dosing in the United States represents a key milestone in the global clinical development of the drug candidate.
CS231295 has been designed to selectively inhibit Aurora B kinase overexpression in tumours, with the aim of inducing synthetic lethality in genetically vulnerable cancers, including those with RB1 deficiency. Its ability to cross the blood-brain barrier is intended to improve treatment potential for primary brain tumours and brain metastases.
According to the company, the candidate has also demonstrated broad anti-tumour activity in preclinical studies, including anti-angiogenic effects and modulation of the tumour microenvironment. It has shown potential for use in combination with chemotherapy, targeted therapies and immunotherapy.
Preclinical data indicated strong pharmacodynamic activity, favourable pharmacokinetics and a good safety profile. ThalassaX Therapeutics stated that no drug candidate with a similar design has previously entered global clinical trials.
CS231295 received investigational new drug (IND) approval from China's National Medical Products Administration (NMPA) in December 2024, followed by first-in-human dosing in China in May 2025. The U.S. Food and Drug Administration (FDA) cleared the IND application in July 2025, enabling parallel clinical development in both countries. The first U.S. patient dosing is expected to support the programme's global clinical development and future study planning.
Source: businesswire.com
