Breast cancer breakthrough: what is olaparib, the drug used for treatment in successful new trial?

Scientists believe they’ve made a significant breakthrough in breast cancer treatment through use of targeted cancer drug olaparib.

A major trial into use of the drug has shown that giving olaparib to women following chemotherapy significantly reduces the risk of inherited breast cancer returning or spreading.

The trial showed that 85.9% of patients were free of their cancer after a median average of 2.5 years following treatment, compared with 77.1% who had received a placebo. Overall, this represented a 42% overall drop in the risk of cancer returning.

Similarly, 87.5% of olaparib patients were alive and free of disease which had spread to other parts of their body, compared with 80.4% who were given a placebo, a 43% drop in the risk of cancer spreading via distant metastases.

Until recently, olaparib was only used to treat advanced cancers, but scientists running the study say it demonstrates the effectiveness of the drug at the early or “curative” stage.

Results of the study, conducted by a number of international partners, were published in the

The New England Journal of Medicine.

The ICR said the trial suggested 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”.

OlympiA steering committee chair Professor Andrew Tutt, professor of oncology at the ICR, said in a statement: “We are thrilled that our global academic and industry partnership in OlympiA has been able to help identify a possible new treatment option for women with early-stage breast cancer who have inherited mutations in their BRCA1 or BRCA2 genes.

“Women with early-stage breast cancer who have inherited BRCA1 or BRCA2 mutations are typically diagnosed at a younger age. Up to now, there has been no treatment that specifically targets the unique biology of these cancers to reduce the rate of recurrence, beyond initial treatment such as surgery, hormone treatment, radiotherapy and chemotherapy.

“This major international study coordinated by the Breast International Group shows that giving olaparib for a year to patients with inherited BRCA mutations after they have completed initial treatment increases the chances that they will remain free of invasive or metastatic breast cancer.”