MSD and AstraZeneca’s Lynparza will be the first PARP inhibitor to be reviewed in Europe for the treatment of breast cancer, after the European Medicines Agency validated the drug’s marketing application in this setting.

The companies are seeking permission to market the drug for use in patients with deleterious or suspected deleterious BRCA-mutated, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer who have been previously treated with chemotherapy in the neoadjuvant, adjuvant or metastatic setting.

Should Lynparza (olaparib) be allowed onto the market, identification of a patient’s BRCA status would become “a critical step” in disease management in addition to their hormone receptor and HER2 status, the firms note.

The submission rides on results of the Phase III OlympiAD trial, which showed that the PARP inhibitor significantly prolonged progression-free survival compared with chemotherapy (median 7.0 versus 4.2 months) and reduced the risk of disease progression or death by 42 percent.

While treatment options have expanded over the last thirty years, there is still no cure for patients diagnosed with MBC and only 26.9 percent of patients survive for five years after diagnosis, highlighting the unmet need in the area.

US regulators green-lighted Lynparza for use in the treatment of BRCA-mutated HER2-negative metastatic breast cancer back in January, making it the first PARP inhibitor to be approved beyond ovarian cancer.

Olaparib was first developed as a cancer treatment following landmark research by UK scientists at the Breast Cancer Now Research Centre at The Institute of Cancer Research, London in 2005, who showed for the first time that cancer cells with BRCA1 and BRCA2 mutations were very sensitive to PARP inhibitors.

The drug was approved for ovarian cancer on both sides of the Atlantic in 2014.