New HER2-targeting drug Perjeta approved for metastatic breast cancer patients

The FDA has approved Perjeta (pertuzumab) for patients with HER2-positive breast cancer that is metastatic or has recurred locally and can't be surgically removed. Perjeta should be used in combination with Herceptin (trastuzumab) and docetaxel in patients who haven't had a previous therapy or have relapsed after adjuvant treatment.Perjeta is a monoclonal antibody that works by preventing the HER2 receptor from pairing with other HER receptors and stymieing the proliferation of cancer cells. Perjeta and Herceptin are thought to complement one another as they both target HER2 but do so in different areas.The approval comes on the heels of a priority review, which was granted on evidence out of the phase 3 CLEOPATRA trial. 808 previously untreated, metastatic HER2-positive breast cancer patients were randomized to receive either the Perjeta-based regimen or Herceptin plus docetaxel and placebo. Patients in the Perjeta arm had a median progression-free survival of 18.5 months compared with 12.4 months in the Herceptin-docetaxel arm. Side effects include neutropenia, febrile neutropenia and diarrhea.Perjeta is also being studied in early-stage HER2-positive breast cancer and HER2-positive gastric cancer.