- Kazia Therapeutics Limited announced new findings on **September 11, 2025**, from a collaborative research program on **paxalisib monotherapy** in **Stage IV HER2-positive metastatic breast cancer patients**.  **[1075880_0001193125-25-200822_d98475d6k.htm:0]** **[1075880_0001193125-25-200822_d98475dex991.htm:0]** 
- The study demonstrated that paxalisib achieved a **complete (100%) disruption of circulating tumor cell (CTC) clusters** containing three or more cells and a **statistically significant reduction in single circulating tumor cells**.  **[1075880_0001193125-25-200822_d98475dex991.htm:0]** 
- This disruption of CTCs and CTC clusters is significant as they are considered **biomarkers of aggressive disease and metastasis**.  **[1075880_0001193125-25-200822_d98475dex991.htm:0]** 
- These results extend the understanding of paxalisib's potential to HER2-positive disease, complementing an ongoing Phase 1b trial in triple-negative breast cancer.  **[1075880_0001193125-25-200822_d98475dex991.htm:0]**

Kazia Therapeutics Reports New Paxalisib Findings in Breast Cancer

- Kazia Therapeutics announced new ex vivo study findings for its investigational drug, **paxalisib**, demonstrating a **statistically significant reduction in single circulating tumor cells** and **complete (100%) disruption of circulating tumor cell (CTC) clusters** in **Stage IV HER2-positive metastatic breast cancer patients**.  **[1075880_20250911CN71184:0]** 
- This study highlighted paxalisib's ability to disrupt CTC clusters, which are considered **biomarkers of aggressive disease and metastasis**, thereby extending the drug's potential beyond triple-negative breast cancer.  **[1075880_20250911CN71184:0]** 
- These findings complement an ongoing Phase 1b trial in Stage IV triple-negative breast cancer, where initial patient data announced in **July 2025** also showed significant reductions in circulating tumor cells and clusters.  **[1075880_20250911CN71184:0]** 
- Detailed datasets from the HER2-positive breast cancer study have been submitted for presentation at an upcoming global oncology meeting in **2025**.  **[1075880_20250911CN71184:0]**

KAZIA THERAPEUTICS (KZIA)