Regulators on both sides of the Atlantic have accepted for review Pfizer’s PARP inhibitor talazoparib as a treatment for women with a hereditary BRCA mutation.

The submission is based on data from the EMBRACA trial, which pitted the drug against chemotherapy in patients with germline (inherited) BRCA-mutated (gBRCAm), HER2-negative locally advanced or metastatic breast cancer.

The study met its primary endpoint, showing superior progression-free survival (PFS) with talazoparib versus chemotherapy (physician’s choice), which was consistent across prespecified subgroups, including those who had a history of brain metastases, and those previously treated with chemotherapy.

Median PFS was 8.6 months for patients in the talazoparib arm versus 5.6 months for those receiving chemo, while patients receiving the PARP inhibitor were 45.8 percent less likely to have disease progression.

On the safety side, grade 3 or higher adverse reactions with talazoparib that occurred with a frequency of at least 10 percent were anemia (35 percent), neutropenia (17 percent) and thrombocytopenia (17 percent).

Mace Rothenberg, chief development officer, Oncology, Pfizer Global Product Development, said the filing acceptances in the US and EU are an example of the success of the firm’s precision medicine approach to drug development, in this case targeting the faulty DNA damage repair process linked with BRCA mutations.

“We are now one step closer to offering a potential alternative to chemotherapy for these patients,” he noted.

In the US, the submission has been assigned a priority review, which should significantly shorten the time frame for regulatory assessment.

Pfizer picked up rights to talazoparib via its $14-billion purchase of Medivation in 2016.