Kazia Therapeutics is charting a new course for paxalisib in treating glioblastoma (GBM) following a Type C meeting with the FDA. While the agency indicated that overall survival (OS) data from the GBM-AGILE study wouldn't support accelerated approval, it could be considered for traditional approval. This decision pivots Kazia's regulatory strategy as it seeks to bring the brain-penetrant PI3K / Akt / mTOR pathway inhibitor to market.
The FDA's feedback emphasized that the secondary endpoint OS data from the GBM-AGILE study are supportive and informative for designing and executing a pivotal registrational study in pursuit of a standard approval. Kazia and the FDA have aligned on critical elements of a proposed Phase 3 trial, including the patient population, primary endpoint, and comparator arm.
GBM-AGILE Study and OS Improvement
In July 2024, Kazia reported topline results from the GBM-AGILE study, revealing that newly diagnosed unmethylated (NDU) glioblastoma patients treated with paxalisib demonstrated a clinically meaningful improvement in overall survival (OS) compared to the standard of care. Specifically, a prespecified secondary analysis showed a 3.8-month OS improvement in the paxalisib arm.
Dr. John Friend, CEO of Kazia, stated, "We appreciate the extensive and thoughtful feedback from the FDA, which provides us with added clarity with respect to paxalisib's potential registration pathway for the treatment of patients with NDU glioblastoma. We believe data from the GBM-AGILE trial, including the prespecified secondary endpoint, which demonstrated a 3.8-month OS improvement, provides evidence supporting a clinically meaningful efficacy signal that merits further testing paxalisib in this patient population in a larger, pivotal study."
Paxalisib's Broader Development
Beyond glioblastoma, paxalisib is under investigation for pediatric brain cancer and brain metastases. The FDA has granted Orphan Drug and Rare Pediatric Disease Designations for diffuse intrinsic pontine glioma (DIPG) and atypical teratoid/rhabdoid tumors (AT/RT), potentially qualifying Kazia for pediatric review vouchers upon product approval. Recent data presented at the San Antonio Breast Cancer meeting also highlighted synergistic activity between paxalisib and immunotherapy, suggesting its potential in breast cancers with PI3K pathway mutations.
Next Steps for Kazia
Kazia is currently evaluating several options and plans to outline its path forward to maximize shareholder value by the end of January 2025. This includes further development of paxalisib in NDU glioblastoma and exploring its potential in other cancer types. The company's strategic decisions will be guided by the FDA's feedback and the clinical data generated to date.
