Australian oncology biotechnology company Kazia Therapeutics has reported a 100% clinical benefit rate among the first six evaluable patients treated with paxalisib in a study involving Stage IV triple-negative breast cancer.
The early findings include a durable complete metabolic response that has remained ongoing since November 2025.
Kazia is developing paxalisib as part of its strategy to target cancer biology, restore anti-tumour immune activity and address mechanisms of treatment resistance.
All six evaluable patients demonstrated clinical benefit following treatment.
The company also reported reductions in biological markers associated with metastatic progression and immune exhaustion.
Metastasis-associated circulating tumour-cell clusters declined by a median of 83% across the evaluable patients, while terminally exhausted T cells decreased by a median of 51%.
No treatment-related serious adverse events were reported in the initial cohort.
Triple-negative breast cancer is an aggressive form of breast cancer defined by the absence of oestrogen receptor, progesterone receptor and HER2 expression, limiting the use of several established targeted therapies.
Patients with metastatic disease therefore continue to face a substantial need for treatment strategies capable of generating durable responses and overcoming resistance.
The findings provide an early indication of paxalisib's potential activity in advanced triple-negative breast cancer, although additional patients and longer follow-up will be required to establish the durability and broader clinical significance of the observed responses.
Kazia is continuing clinical evaluation of the therapy as it builds evidence around the biological and immune effects of treatment.
