PR Newswire·Sep 1, 2026, 7:15 AM ET

Kazia Therapeutics Expands Paxalisib Clinical Trial into HR+/HER2- Breast Cancer, Supported by Preclinical Data Showing Strong Clinical Activity and Safety in HR+ Breast Cancer

Kazia Therapeutics announced new preclinical data showing paxalisib combined with standard-of-care therapy is well-tolerated & produces statistically significant antitumor activity in HR+/HER2- breast cancer.
The data indicates paxalisib resensitizes CDK4/6 inhibitor-resistant tumors to standard therapy through a distinct epigenetic mechanism not observed with the FDA-approved inhibitor gedatolisib.
Kazia is expanding its ongoing TNBC clinical trial into a three-arm study to evaluate paxalisib plus fulvestrant, with palbociclib, versus standard-of-care in pre-treated HR+/HER2- metastatic breast cancer patients.
A related provisional patent application has been filed to support the Company's findings regarding paxalisib's unique attributes & the identified novel PI3K/mTOR biomarker.
The trial will randomize patients to three arms: paxalisib 15mg plus fulvestrant & palbociclib, paxalisib 30mg plus fulvestrant & palbociclib, or a standard-of-care comparator of fulvestrant alone.
Primary trial endpoints include safety & tolerability, while secondary endpoints cover progression-free survival, overall response rate, & overall survival.
First patient enrollment for the expansion is expected by the end of 2026, with full enrollment anticipated by the end of 2027.
Clinical updates are anticipated throughout 2027, with a full data readout expected in 2028.
The Company states it has sufficient capital from recent financing to fund this program through completion.