Dr Visvader said combined treatment with ABT-737 and docetaxel (a commonly used chemotherapy drug for treating breast cancer) in mice transplanted with human breast cancer cells improved tumour response and survival rates, when compared to docetaxel as a single agent. ABT-737 alone was not effective in treating cancers with high levels of Bcl-2, nor was it effective in treating cancers that did not express Bcl-2.

"The research suggests that these agents make the cancer cells more vulnerable to chemotherapy," Dr Visvader said. "We are particularly excited that the research shows a good response in Bcl-2-expressing breast cancer, including basal-like breast cancer, which is often the most aggressive and hardest to treat."

Dr Lindeman said the research could lead to the development of new treatment regimens that make resistant and difficult-to-treat breast cancers more vulnerable to conventional chemotherapy treatments. "We have had a good result in pre-clinical models of disease, but we are still a way off this being used in humans," Dr Lindeman, who is also an oncologist at The Royal Melbourne Hospital, said. "We hope that these results could see a clinical trial of navitoclax for treating breast cancer with high Bcl-2 levels within the next few years."

Source: Walter and Eliza Hall Institute