Pertuzumab, in combination with trastuzumab and chemotherapy (the pertuzumab-based regimen), has been approved by the FDA for adjuvant treatment of HER2-positive early breast cancer at high risk of recurrence.
Patients should receive the adjuvant pertuzumab-based regimen for 1 year (up to 18 cycles). The FDA has also converted the previously granted accelerated approval of the pertuzumab-based regimen to full approval for neoadjuvant treatment of HER2-positive, locally advanced, inflammatory, or early-stage breast cancer (either greater than 2 centimeters in diameter or node-positive). People receiving the neoadjuvant pertuzumab-based regimen should continue pertuzumab and trastuzumab after surgery to complete 1 year of treatment.
The FDA-approved use of the pertuzumab-based regimen for adjuvant treatment of HER2-positive early breast cancer at high risk of recurrence is based on results of the phase III APHINITY study. At the time of the primary analysis with a median of 45.4 months follow-up:
* In the overall study population, pertuzumab, trastuzumab, and chemotherapy significantly reduced the risk of invasive breast cancer recurrence or death by 18 percent compared to trastuzumab and chemotherapy alone (HR=0.82, 95% CI 0.67-1.00, p=0.047).
* High-risk patients included patients such as those with lymph node-positive or hormone receptor-negative breast cancer. The subgroup results were as follows:
* Lymph node-positive subgroup (HR=0.77, 95% CI 0.62-0.96)
* Hormone receptor-negative subgroup (HR=0.76, 95% CI 0.56-1.04)
* Hormone receptor-positive subgroup (HR=0.86, 95% CI 0.66-1.13)
* Lymph node-negative subgroup (HR=1.13, 95% CI 0.68-1.86)
The most common severe (grade 3/4) side effects with the pertuzumab-based regimen are low levels of white blood cells with or without a fever, diarrhea, decrease in certain types of white blood cells, decrease in red blood cells, fatigue, nausea, and mouth blisters or sores. The most common side effects are diarrhea, nausea, hair loss, fatigue, nerve damage, and vomiting.
The supplemental Biologics License Application for the pertuzumab-based regimen for adjuvant treatment of HER2-positive early breast cancer was granted Priority Review, a designation given to medicines the FDA has determined to have the potential to provide significant improvements in the treatment, prevention, or diagnosis of a disease.
Pertuzumab is also approved for use in combination with trastuzumab and docetaxel in people who have HER2-positive metastatic breast cancer and who have not received anti-HER2 therapy or chemotherapy for metastatic breast cancer.