FDA approves Perjeta for late-stage breast cancer

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The FDA recently approved a new drug for treatment of late-stage breast cancer. | FILE PHOTO

The U.S. Food and Drug Administration has approved Perjeta, a new anti-HER2 therapy, to treat patients with HER2-positive late-stage (metastatic) breast cancer.

Intended for patients who have not received prior treatment for metastatic breast cancer with an anti-HER2 therapy or chemotherapy, Perjeta, pronounced pertuzumab, is combined with trastuzumab, another anti-HER2 therapy, and docetaxel, a type of chemotherapy.

HER2 is a protein involved in normal cell growth. It is found in increased amounts on some types of cancer cells (HER2-positive), including some breast cancers.

Breast cancer is the second leading cause of cancer-related death among women. This year an estimated 226,870 women will be diagnosed with breast cancer, and 39,510 will die from the disease. About 20 percent of breast cancers have increased amounts of the HER2 protein.

Perjeta is a humanized monoclonal antibody, manufactured through biotechnology methods. It is administered intravenously and is believed to work by targeting a different part of the HER-protein than trastuzumab, resulting in further reduction in growth and survival of HER2-positive breast cancer cells.

“Since trastuzumab was first approved more than a decade ago, continued research has allowed us to better understand the role HER2 plays in breast cancer,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “This research provided the background to combine two targeted drugs — trastuzumab and Perjeta with docetaxel to slow disease progression in breast cancer.”

The safety and effectiveness of Perjeta were evaluated in a single clinical trial involving 808 patients with HER2-positive metastatic breast cancer who were tested prior to treatment to determine if the HER2 protein was increased. Patients were randomly assigned to receive Perjeta, trastuzumab and docetaxel or trastuzumab and docetaxel with a placebo.

The study was designed to measure the length of time a patient lived without the cancer progressing; this is known as progression-free survival (PFS). Those treated with the combination containing Perjeta had a median PFS of 18.5 months, while those treated with the combination containing placebo had a median PFS of 12.4.

Perjeta is marketed by South San Francisco-based Genentech, a member of the Roche Group.