Kazia Therapeutics Limited has announced preliminary results from the first patient in its Phase 1b trial evaluating a combination regimen of Paxalisib, pembrolizumab, and standard chemotherapy for metastatic triple-negative breast cancer. The early data from a 61-year-old patient showed a greater than 50% reduction in circulating tumor cells (CTCs) after 21 days of treatment. This reduction in both CTC numbers and clusters, as well as a decrease in the mesenchymal phenotype, suggests potential mechanistic synergy with the combination regimen, as opposed to chemotherapy or immunotherapy alone. The study is ongoing, with plans to expand the cohort size to further assess safety, tolerability, and pharmacodynamics. A comprehensive analysis of immune microenvironment and CTC kinetics across all patients will be conducted, with longer-term follow-up focusing on imaging, progression-free survival, and molecular biomarker correlation.