Australian specialists may hold key to ovarian cancer treatment

Three Australian cancer treatment centres are involved in a drug trial that could see the next major advancement in ovarian cancer therapy.

Westmead Hospital in Sydney, Flinders Medical Centre in South Australia and Icon Cancer Care in South Brisbane are participating in the first clinical trial of Cantrixil, a locally developed molecule by biotech Novogen, along with US hospitals Peggy and Charles Stephenson Cancer Centre and Mary Crowley Cancer Research Centre.

Associate Professor Jim Coward, an oncologist at Icon Cancer Care in South Brisbane, is leading the trial that could enable intraperitoneal (IP) chemotherapy to again become a viable treatment option in patients where it has become ineffective due to resistance.

The Phase 1 trial, which is designed to understand the safety profile of Cantrixil in human subjects and establish a maximum tolerated dose (MTD) for the drug, commenced in December 2016 and preliminary results are expected as early as next year.

Ovarian cancer is the eighth most common cancer in women, and the sixth most common cause of cancer death for women in Australia. The Australian Institute of Health and Welfare estimates that in 2017, 1580 new cases will be diagnosed and 1047 women will die from ovarian cancer.

"We've seen massive developments in other types of cancer but ovarian cancer has remained a challenge and, despite it being an unforgiving disease for women, treatment options have fallen behind as money and research are focused elsewhere," Associate Professor Coward said.

"The survival rate for ovarian cancer is poor because of the high rate of relapse after standard-of-care treatment and the late stage at which the disease tends to be diagnosed. The vast majority of patients who relapse will eventually become resistant to chemotherapy, so it's imperative that we have a bigger portfolio of treatment options."

Recurrent, chemo-resistant ovarian cancer is thought to be due to a subgroup of slow-growing, drug-resistant cancer cells with stem-like properties and a high capacity for tumour repair. These are often referred to as tumour-initiating cells or 'cancer stem cells'.

"Cantrixil could be a compelling treatment for patients with recurrent ovarian cancer because it has shown evidence in the laboratory of being able to target and kill the sub-population of cancer stem cells or tumour-initiating cells that are responsible for cancers originating, metastasising and relapsing," Associate Professor Coward said.

"This new treatment is being developed as an IP chemotherapy that we hope will be used as both first line and recurrent therapies in combination with carboplatin administered intravenously (IV) for epithelial ovarian cancer, which is the most common form of ovarian cancer, comprising 90% of cases.

"We know that if a surgeon is able to remove all of the visible disease during an ovarian cancer patient's initial operation, combination IP and IV therapy is associated with vastly superior outcomes."

Novogen CEO and Executive Director Dr James Garner said: "We are pleased with the progress to date in the phase 1 study of Cantrixil. Novogen is fortunate to be working with highly experienced clinicians at leading trial centres. We remain excited by the potential for Cantrixil to become an important addition to the treatment landscape in ovarian cancer and are grateful to those patients who are participating in the study."

Women interested in participating should discuss the Cantrixil trial with their oncologist.