Today, the FDA approved approved talazoparib (Talzenna), a drug of the PARP inhibitor class for breast cancer patients who possess harmful (or suspected harmful) BRCA1 mutations in the context of locally advanced or metastatic breast cancer. Importantly, before approval for the new drug, patients must undergo testing with an FDA-approved companion test from Myriad Genetics, the BRACAnalysis CDx test, which was also granted approval.
The FDA based its approvals on data from the open-label, phase 3 EMBRACA trial which was designed to evaluate Talzenna compared with chemotherapy in 431 patients with HER2-negative, germline BRCA-mutant locally advanced or metastatic breast cancer.
Breast cancer patient participants could have no more than three prior chemotherapy regimens for locally advanced or metastatic disease, and they were required to have received treatment with an anthracycline and/or taxane (unless they were not eligible for that treatment) in the neoadjuvant (before treatment), adjuvant (during treatment) and/or metastatic (Stage IV breast cancer) setting.
Estimated average progression-free survival (time to disease progression or death) in the Talzenna arm was 8.6 months compared to 5.6 months in the chemotherapy arm.
Talzenna is the second PARP inhibitor to be approved for the treatment of breast cancer. Lynparza (olaparib) was the first drug in the PARP class to be approved for breast cancer.
The prescribing information for Talzenna includes warnings and precautions for myelodysplastic syndrome/acute myeloid leukemia, myelosuppression, and embryo-fetal toxicity. The most common side effects were fatigue, anemia, nausea, neutropenia, headache, thrombocytopenia, vomiting, alopecia, diarrhea and decreased appetite.