On Sept. 30, 2013, the U.S. Food and Drug Administration (FDA) granted accelerated approval for using the targeted therapy medicine Perjeta (chemical name: pertuzumab) in combination with Herceptin (chemical name: trastuzumab) and Taxotere (chemical name: docetaxel) before surgery to treat HER2-positive, early-stage (the cancer must be larger than 2 cm or cancer must be in the lymph nodes), inflammatory, or locally advanced-stage breast cancer with a high risk of metastasizing or becoming fatal.
Doctors call treatments given before surgery neoadjuvant treatments.
This neoadjuvant Perjeta regimen is the first and only neoadjuvant regimen approved by the FDA to treat breast cancer.
The FDA approved Perjeta to be used in this way based on results from the NEOSPHERE study that found about 40% of women diagnosed with either locally advanced or inflammatory HER2-positive breast cancer who were treated with Perjeta, Herceptin, and Taxotere before surgery had a pathologic complete response compared to women who were treated only with Herceptin and Taxotere. Most women continued to get Herceptin for a year after surgery.
Locally advanced breast cancer is breast cancer that has spread beyond the breast to nearby tissue, such as the skin or the tissue of the chest wall that hadn’t been treated with chemotherapy yet.
One way doctors judge the effectiveness of treatment given before surgery is to look at the tissue removed during surgery to see if any active cancer cells are present. If no active cancer cells are there, doctors call it a “pathologic complete response.” Some doctors believe that a pathologic complete response to neoadjuvant treatment means the cancer is less likely to come back.
HER2-positive breast cancers have too many copies of the HER2/neu gene, which make too much of the HER2 protein. HER2-positive breast cancers tend to be more aggressive than cancers that are HER2-negative. Both Herceptin and Perjeta work against HER2-positive breast cancers by blocking the cancer cells' ability to receive growth signals. Both medicines are given intravenously.
Herceptin, also a targeted therapy medicine, is FDA-approved to treat advanced-stage, HER2-positive breast cancer and to lower the risk of recurrence (the cancer coming back) of early-stage, HER2-positive breast cancer with a high risk of recurrence.
Earlier research suggested that Perjeta could boost Herceptin’s ability to weaken or destroy HER2-positive breast cancers. So this study looked to see how the two medicines could be used together to treat HER2-positive breast cancer before surgery. Doctors sometimes call the Herceptin-Perjeta combination “dual HER2 antibody therapy.”
In June 2012, the FDA approved using Perjeta in combination with Herceptin and Taxotere to treat HER2-positive, metastatic breast cancer that hadn’t been treated with either Herceptin or chemotherapy yet.
In the NEOSPHERE study, researchers randomly assigned 417 women diagnosed with either locally advanced or inflammatory HER2-positive breast cancer to one of four treatment regimens before surgery:
- Herceptin and Perjeta
- Herceptin and Taxotere
- Perjeta and Taxotere
- Herceptin, Perjeta, and Taxotere
After neoadjuvant treatment was done, the women had surgery to remove the cancer. The researchers recorded how many women had a pathologic complete response.
In each treatment group, some women had a pathologic complete response. Still, more women -- about 40% -- had a pathologic complete response in the Herceptin, Perjeta, and Taxotere group. About 21% of the women in the Herceptin and Taxotere group had a pathologic complete response.
The NEOSPHERE study is a phase II trial. Phase II trials look at how effective a treatment is. For Perjeta to receive full FDA approval to be used in the neoadjuvant setting and to treat early-stage breast cancer, results from the ongoing phase III APHINITY trial must be submitted to the FDA for review. Phase III trials compare the safety and effectiveness of a new treatment to the current standard of care. APHINITY is comparing Perjeta, Herceptin, and chemotherapy to Herceptin and chemotherapy to treat HER2-positive, early-stage breast cancer after surgery. The results from the APHINITY trial are expected in 2016.
Like many breast cancer treatments, Herceptin and Perjeta can cause side effects, some of them severe. Problems with heart function or developing heart failure can be side effects of both Herceptin and Perjeta. People receiving these medicines should have their heart function evaluated before and during treatment.
The most common side effects reported by the women who got Perjeta were:
- hair loss
- low white blood cell count
If you’ve been diagnosed with HER2-positive, early-stage, locally advanced, or inflammatory breast cancer with a high risk of metastatic recurrence, you may want to ask your doctor about this approval of Perjeta and whether treatment before surgery with a Perjeta regimen should be part of your treatment plan.