A major trial of the drug Olaparib has found it cuts the likelihood of hereditary breast cancer returning after treatment.
The results, published in the New England Journal of Medicine and presented online at the American Society of Clinical Oncology, showed how the drug reduced the relative risk of invasive recurrence, second cancers or death by 42%.
The trial was stopped early after two and half years instead of the planned ten years after the impact of the drug became clear.
At three years, 85.9% of patients treated with Olaparib, otherwise known as Lynparza, remained alive and free of invasive breast cancer and second cancers versus 77.1% on placebo.
The findings from the major OlympiA phase III trial suggest that olaparib, which exploits a genetic weakness in cancer cells, could become a new treatment option to reduce the risk of recurrence or metastasis in women with inherited forms of high-risk early breast cancer – and could lead to more patients being cured. The trial was led by Professor Andrew Tutt, Professor of Oncology at King's.
Olaparib works by stopping cancer cells from being able to repair their DNA by inhibiting a molecule called PARP – causing cancer cells to die. It works particularly well for patients with faulty versions of the BRCA1 or BRCA2 genes – which are normally involved in another system for repairing DNA. Cancer cells cannot survive if they do not have functioning DNA repair involving either PARP, or BRCA1 or BRCA2.
We are thrilled that our global academic and industry partnership has been able to help identify a possible new treatment for women with early stage breast cancer who have mutations in their BRCA1 or BRCA2 genes. Olaparib has the potential to be used as a follow-on to all the standard initial breast cancer treatments to reduce the rate of life-threatening recurrence and cancer spread for many patients identified through genetic testing to have mutations in these genes.– Professor Tutt, from the Breast Cancer Now Research Unit
He added: "Women with early-stage breast cancer who have inherited BRCA mutations are typically diagnosed at a younger age. Up to now, there has been no treatment that specifically targets these mutations to reduce the risk of recurrence beyond the standard treatments available for early breast cancer. This major international study coordinated by the Breast International Group shows that giving olaparib for a year after completion of chemotherapy to patients with BRCA1 and 2 mutations increases the chances that they will remain free of invasive or metastatic cancer. These results reinforce how collaborative cancer research deepens our understanding of treating familial cancers and shows the value of testing for these mutations in patients with early breast cancer."
