On October 2, 2025 Kazia Therapeutics Limited (NASDAQ: KZIA), an oncology-focused drug development company, reported a substantial reduction in tumor burden from a single-patient expanded access case in triple-negative breast cancer (TNBC) treated with a combination regimen that included the Company’s investigational pan-PI3K/mTOR inhibitor, paxalisib (Press release, Kazia Therapeutics, OCT 2, 2025, View Source [SID1234656402]). After three weeks of combination immunotherapy/chemotherapy plus paxalisib, imaging performed at the treating institution showed an 86% reduction in overall tumor burden.
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
The patient is a 40+ year old female initially diagnosed with TNBC in April 2023. She received neoadjuvant chemotherapy and immunotherapy, followed by bilateral mastectomy six weeks post-treatment with no residual cancer detected, followed by radiation therapy. Approximately two years later, the patient was diagnosed with metastatic disease to bone and lungs. She was then treated under a single-patient expanded-access protocol with an immunotherapy/chemotherapy regimen plus paxalisib. After three weeks of therapy, imaging demonstrated an 86% overall tumor reduction. The patient’s profile and treatment approach are highly similar to the inclusion and combination strategy being evaluated in Kazia’s Phase 1b TNBC study, which is assessing paxalisib in combination with Keytruda (pembrolizumab) and chemotherapy.
"Although this is a single-patient expanded-access case, the speed and magnitude of tumor regression are highly encouraging and align with our scientific rationale for combining paxalisib with immune checkpoint blockade," said Dr. John Friend, M.D., Chief Executive Officer of Kazia Therapeutics. "This experience reinforces our commitment to our ongoing, company sponsored Phase 1b trial in advanced breast cancer, and it echoes the recent ex-vivo findings showing disruption of circulating tumor cell clusters with paxalisib."
About the ongoing Phase 1b TNBC trial
Kazia is conducting a company-sponsored multi-centered Phase 1b study in Australia evaluating paxalisib in combination with Keytruda and chemotherapy for advanced breast cancer, including TNBC. The study is designed to assess safety, preliminary anti-tumor activity, and translational biomarkers, including effects on circulating tumor cells and cluster dynamics to better understand how paxalisib may enhance immunotherapy responsiveness in this population.