A new treatment is being heralded as a ‘smart-bomb’ for breast cancer following very promising studies in a Phase III clinical trial based in the US.
Researchers at the Duke Cancer Institutes administered a new drug ‘T-DM1’ to almost 1000 women with the specific breast cancer type ‘HER-2 positive’, and found it prevented patients’ advanced tumours from progressing while delivering fewer side effects compared to conventional treatments.
“As a clinician who takes care of breast cancer patients, it’s important to have a treatment that is both effective and well tolerated,” said director of the Breast Cancer Clinical Program at the Duke Cancer Institute, Kimberley Blackwell.
“This is a drug that brings us another step closer to treating cancer without the side effects of chemotherapy.”
HER-2 breast cancer is distinguished by high levels of a protein known as ‘human epidermal growth factor’ which promotes cancer cell growth. It accounts for about 20% of invasive breast cancers.
Currently, an antibody called trastuzumab is being used effectively to treat this type of breast cancer, because it seeks out and binds to the HER-2 protein, interfering with its ability to fuel tumour growth.
In T-DM1, scientists have been able to bind trastuzumab directly with chemotherapy. The two agents travel together, targeting the HER-2 proteins, and delivering the chemotherapy to the cell without impacting on surrounding healthy tissue.
“This is a more targeted way of delivering chemotherapy to HER-2 overexpressed cells,” Blackwell said.
“It delivers the drug directly to the cancer cells, while avoiding cells that don’t really need to receive chemotherapy, which keeps patients from getting sick.”
This study showed the average time people on T-DM1 experienced no cancer growth was 9.6 months, compared to 6.4 months for people receiving the current standard treatment.
After two years, 65.4% of the T-DM1 patients were alive, compared to 47.5% in the control group.
The difference is certainly meaningful to those patients with this form of invasive breast cancer. However it does fall just short of a high, predetermined statistical benchmark which would allow this drug to pass straight into pharmaceutical development and distribution.
Researchers will therefore continue to analyse patient survival and are hopeful the benefits will satisfy this benchmark in the very near future.