In a nutshell
This article reviewed data from recent clinical trials investigating the drug pertuzumab (perjeta) as treatment for metastatic HER2+ breast cancer.
Some background
HER2 (human epidermal growth factor receptor 2) is a protein found on the surface of some cancer cells. This complex responds to molecules called growth factors, and stimulates aggressive cancer growth and spread. When breast cancer cells possess this complex, the cancer is referred to as a HER2-positive (HER2+) breast cancer.
Trastuzumab (herceptin) was the first drug approved to target the HER2 pathway, has been shown to increase survival, and is currently the standard of care in the treatment of HER2+ breast cancer patients. However, some patients fail to benefit from trastuzumab treatment, explaining the need for additional HER2 targeted therapies.
Permutuzab is a recently approved drug that also targets the HER2 pathway. It works by blocking the activation of the HER2 complex (a process known as dimerization) in a different manner than pertuzumab. Early trials have suggested that the addition of pertuzumab to trastuzumab (a strategy known as dual blockade) may be more effective at delaying cancer progression than either drug given alone.
Methods & findings
A recent phase III trial reviewed in this article included 808 women diagnosed with HER2+ metastatic breast cancer. Chemotherapy with dual HER2 blockade (pertuzumab and trastuzumab) was compared to treatment with chemotherapy and trastuzumab plus a placebo. Results showed that dual HER2 blockade showed better response rates to treatment, and significantly increased progression-free survival (PFS; the length of time between treatment and until the disease worsens or progresses).
80.2% of patients receiving dual HER2 blockade responded to treatment (assessed by tumor shrinkage), compared to 69.3% of patients receiving trastuzumab alone. Average PFS with dual blockade treatment was 18.5 months, compared to only 12.4 months with trastuzumab.
The bottom line
This review concluded that pertuzumab, when received in addition to trastuzumab, provides a substantial benefit to the prognosis of HER2-positive metastatic breast cancer patients.
What’s next?
Consult with your physician regarding the benefits of dual HER2 blockade in the treatment of breast cancer.
Published By :
Clinical Cancer Research
Date :
Aug 13, 2013
