AstraZeneca has unveiled new data showing a significant reduction in the risk of death or disease progression in certain patients with breast cancer taking its PARP inhibitor Lynparza.

Results of the Phase III OlympiAD trial, presented at the Amercian Society of Clinical Oncology Meeting, showed that patients with HER2-negative germline BRCA1 or BRCA2-mutated breast cancer treated with Lynparza (olaparib) had a 42-percent reduced risk of disease worsening or death compared to those who received chemotherapy.

Also, the objective response rate (ORR) was more than doubled, with 59.9 percent of patients in the Lynparza arm showing response to treatment, compared to 28.8 percent of patients treated with chemotherapy, while no new safety signals were identified.

Earlier this year, AZ announced that the trial had met its primary endpoint of showing a significant improvement in progression-free survival in patients taking the drug.

“The OlympiAD data presented today demonstrate the benefit of olaparib in delaying the progression of advanced BRCA-mutated breast cancer. With few alternatives available, a targeted non-chemotherapy oral treatment in this setting could be a beneficial new option for patients,” said Mark Robson, clinic director of the Clinical Genetics Service at Memorial Sloan Kettering Cancer Center, New York and principal investigator of OlympiAD.

Sean Bohen, AZ’ chief medical officer, said the results “mark the first time a targeted therapy shows benefit over the current standard of care for patients with HER2-negative gBRCA-mutated metastatic breast cancer,” and also represent an important milestone for drug as “the first positive Phase III trial in which a PARP inhibitor has shown a significant benefit for patients outside of ovarian cancer.”

In the EU, Lynparza is approved as maintenance treatment for adults with platinum-sensitive relapsed BRCA-mutated (germline and/or somatic) high grade serous epithelial ovarian, fallopian tube or primary peritoneal cancer who are in response (complete or partial) to platinum-based chemotherapy. It is also approved in the US as monotherapy in patients with deleterious or suspected deleterious germline BRCA-mutated advanced ovarian cancer who have been treated with three or more prior lines of chemotherapy.

The drug is also currently being assessed in a separate non-metastatic breast cancer Phase III study called OLYMPIA.