Kazia Therapeutics will partner with Dana-Farber Cancer Institute for a Phase II clinical trial of GDC-0084 in combination with herceptin (trastuzumab) for the treatment of patients with breast cancer that has spread to the brain.

The trial is expected to enrol 22-49 patients with human epidermal growth factor receptor 2 (HER2) positive breast cancer that has metastasised to the brain.

According to Breastcancer.org, nearly 10%-15% of women with stage IV breast cancer develop brain metastases.

Kazia Therapeutics GDC-0084 clinical programme director Dr Jeremy Simpson said: “HER2 is a protein that promotes the growth of cancer cells. Approximately 20-30% of early-stage breast cancers show amplification of a gene associated with HER2, and these patients are generally treated with herceptin, an anti-HER2 monoclonal antibody.

“Approximately 20%-30% of early-stage breast cancers show amplification of a gene associated with HER2.”

“The efficacy of herceptin is well established. However, breast cancer can nevertheless spread to other parts of the body, a process described as metastasis, and in about a third of such cases the brain is the site to which it spreads.

“Such brain metastases are often highly resistant to herceptin, in contrast to the primary tumour, and there remains a substantial need for new therapies in this patient population.”

An Australian biotech company, Kazia is currently developing GDC-0084 as a potential treatment for the primary form of brain cancer known as glioblastoma multiforme.

GDC-0084 is a brain-penetrant phosphoinositide 3-kinase (PI3K) inhibitor designed to target the signaling pathway implicated in nearly 90% of glioblastoma cases.

Dana-Faber will continue to study the drug as part of a separate Phase II clinical trial in adults with newly diagnosed glioblastoma.

The trial is currently taking place at sites in the US, and is expected to include additional sites in Australia next year.