Novel drug combo for triple-negative breast cancer

In the hunt for novel treatments against triple-negative breast cancer, US researchers have combined a new protein inhibitor with a chemotherapy drug.

In this work, the University of Michigan researchers tested drugs separately in triple-negative breast cancer cell lines and in mice with the disease. They then implemented the treatments together.

Preliminary data had shown that inhibiting proteins called cyclin-dependent kinases, or CDKs, might be effective against triple-negative breast cancer. In this study, published in Oncotarget, researchers tested a pharmaceutical-grade CDK inhibitor called CYC065. Additionally, they used the chemotherapy drug eribulin, which had shown promise in prior clinical trials for the treatment of triple-negative breast cancer.

Researchers found that a novel drug combination disrupts multiple factors in an aggressive type of breast cancer. That combination, they found, produced a synergistic effect that was more effective than either drug alone: cancer cells treated with the drug combination were less likely to multiply or spread in cell culture and were less viable in an animal model.

“In this preclinical study, we showed that the combination of CYC065 and eribulin had a synergistic effect against the growth and progression of triple-negative breast cancer,” said study author Jacqueline S Jeruss, MD, PhD, director of the Breast Care Center at the University of Michigan Comprehensive Cancer Center.

The combination of CYC065 with eribulin resulted in less viable triple-negative breast cancer cells, smaller tumour colonies, decreased cell migration and small tumour size in an animal model. UM researchers also identified transcription factors that were affected by CYC065. These processes probably work together to promote cancer cell death.

“We have begun to identify a network of vulnerable and targetable signalling components within the triple-negative cancer cells that can be exploited with CDK inhibitor and chemotherapy treatment to promote triple-negative breast cancer cell death,” Jeruss said.

The next step is for researchers to develop a clinical trial to test the drug combination in patients with triple-negative breast cancer, said Jeruss.