Targeted drug improves survival in early-stage breast cancer

The results from the major phase III OlympiA trial shows the drug improves survival rates in women who have inherited faults in their BRCA1 or BRCA2 genes.

The findings of the study is released today at a virtual plenary session from the European Society of Medical Oncology, with a coordinating effort from the Breast International Group (BIG).

Professor Andrew Tutt, from the School of Cancer & Pharmaceutical Sciences was Chair of the Steering Committee for the study, and was also involved in early laboratory research on PARP inhibitors such as olaparib, and their subsequent clinical development.

"Today's results are great news for many women with inherited breast cancer. Most breast cancers are identified in the early stages and many patients will do very well, but for some, the risk of cancer returning remains unacceptably high, even after chemotherapy," says Tutt.

OlympiA trial researchers studied 1,836 women with HER-2 negative breast cancer, who also had a mutation in their BRCA1 or BRCA2 genes and had undergone standard treatment, including surgery, chemotherapy, hormonal therapies and radiotherapy, where appropriate. Patients were randomly allocated to receive either 300mg twice day of olaparib or a placebo for one year and were then followed up.

The trial will follow participants for a total of 10 years but reported its first results after just two and a half years following a planned review by an independent monitoring committee which found that olaparib reduced the risk of breast cancer returning by 42%.

Professor Tutt, who is also Professor of Oncology at The Institute of Cancer Research in London, said: "OlympiA has shown that after selecting women with inherited BRCA mutations through genetic testing, we can use olaparib to directly target the weakness in their cancer and improve their survival. I hope to see BRCA1 and BRCA2 testing used for more women diagnosed with early-stage breast cancer, so that we can determine who can benefit from this personalized treatment approach. Olaparib provides a much needed new individualized and targeted treatment option to keep more women with inherited breast cancer free of disease and alive and well after their initial treatment."

An estimated 2.3 million people were diagnosed with breast cancer worldwide in 2022, and BRCA1and BRCA2 mutations are found in approximately 5% of breast cancer patients.