EU approves Talzenna for HER2- breast cancer

Pfizer Inc. announced that the European Commission approved Talzenna (talazoparib), an oral poly (ADP-ribose) polymerase (PARP) inhibitor, as monotherapy for the treatment of adult patients with germline breast cancer susceptibility gene (gBRCA)1/2-mutations, who have human epidermal growth factor receptor 2-negative (HER2-) locally advanced (LA) or metastatic breast cancer (MBC). Patients should have been previously treated with an anthracycline and/or a taxane in the (neo)adjuvant, locally advanced or metastatic setting unless patients were not suitable for these treatments. Patients with hormone receptor-positive (HR+) breast cancer should have been treated with a prior endocrine-based therapy, or be considered unsuitable for endocrine-based therapy. This approval follows the medicine’s approval by the FDA in October 2018.

The European Commission’s approval of Talzenna, which was acquired as part of Pfizer’s acquisition of Medivation, is based on results from the EMBRACA trial - the largest Phase III study of a PARP inhibitor in gBRCA-mutated, HER2- LA or MBC. The global trial evaluated once-daily Talzenna compared to physician’s choice standard chemotherapy (capecitabine, eribulin, gemcitabine or vinorelbine) in patients with an inherited BRCA1/2 mutation in triple-negative or HR+/HER2- LA or MBC who may have received up to three prior cytotoxic chemotherapy regimens for their advanced disease. The primary endpoint was progression-free survival (PFS), as assessed by blinded independent central review (BICR).

Comment: Breast cancer is the first indication for Talzenna, although it is also in Phase III for prostate cancer in combination with Xtandi or Johnson & Johnson's Zytiga. Pfizer’s expansion plans for talazoparib include early triple-negative breast cancer and DNA damage repair-deficient prostate cancer, as well as combination use with its PD-L1 inhibitor Bavencio.