Kazia Therapeutics Ltd (ASX:KZA, NASDAQ:KZIA) has wrapped up its Phase 2 study of the glioblastoma treatment paxalisib.
The company has received the final clinical study report, including an abstract summarising the findings of the study, and this data has been accepted for presentation at an upcoming international clinical oncology conference.
Kazia CEO Dr James Garner said: “We are very pleased to have successfully completed this last step in the Phase 2 study of paxalisib and we look forward to sharing detailed data with clinicians and investors over coming months."
The study recruited 30 patients with newly diagnosed glioblastoma and unmethylated MGMT promotor status, a genetic profile that confers primary resistance to temozolomide, the only existing FDA-approved drug treatment for first-line treatment.
Key findings
The study identified 60 milligrams once daily as the maximum tolerated dose (MTD), and this will be used in future studies.
The median overall survival in the intent-to-treat (ITT) population (30 participants) was 15.7 months (the range was from 11.1 months to 19.1 months), which compares very favourably to 12.7 months historically reported with temozolomide in this patient group.
Median progression-free survival (PFS) in the ITT population was 8.4 months (the range was 6.6 months to 10.2 months), representing a substantial increment over the comparable figure of 5.3 months associated with temozolomide.
In the modified ITT population (27 of the participants), which includes only those patients evaluable for efficacy, overall survival increased to 15.9 months (the range was 12.8 months to 19.1 months).
The safety profile of paxalisib was highly consistent with previous clinical studies: hyperglycaemia, oral mucositis, and skin rash were among the most common drug-related toxicities.
“Greatly expanded” understanding
“This study has greatly expanded our understanding of paxalisib and the insights it has provided have informed all our subsequent work with the drug," Garner said. "We are grateful to the clinicians and patients that have participated.
“Paxalisib is now the subject of an ongoing pivotal study in glioblastoma, GBM AGILE, and we hope to see results from that study confirm the very positive signals seen in this Phase 2 trial.”
Dana-Farber Cancer Institute principal investigator Patrick Wen MD said: “We look forward to presenting the final data from this Phase 2 study and continuing our investigations in the multi-drug GBM AGILE study.
“Glioblastoma is a devastating diagnosis and we are encouraged by the prospect of providing new hope to this patient community.”
Shareholder conversion event
Pursuant to an agreement entered into by Novogen Limited, Kazia’s predecessor company, in November 2013, completion of this study satisfies the criteria for the third and final conversion event associated with a convertible note issued to certain shareholders of Triaxial Pty Ltd.
The company will notify the market when it issues shares under this agreement.
Next steps
The GBM AGILE pivotal study in glioblastoma commenced recruitment to the paxalisib arm in January 2021.
At present, recruitment to the paxalisib arm continues in the United States and Canada, and the study is expected to open in Europe and China during the next two quarters.
Final data from the study is expected in the second half of 2023.
Seven other studies of paxalisib are ongoing in glioblastoma, in other forms of primary brain cancer, and in various forms of cancer that has metastasised to the brain.