News about Combined HER2 Treatment

Among women with metastatic, HER2-positive breast cancer, treatment with a combination of HER2-targeted therapies may produce better outcomes than treatment with only a single HER2-targeted therapy. These results were published in the New England Journal of Medicine and were also presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium.    

Approximately 20-25% of breast cancers overexpress (make too much of) a protein known as HER2. Fortunately, the development of drugs that specifically target HER2-positive breast cancer has improved outcomes. These drugs include Herceptin® (trastuzumab), Tykerb® (lapatinib), and the investigational drug pertuzumab.    

To explore whether treatment with both Herceptin and pertuzumab can improve outcomes among women with metastatic, HER2-positive breast cancer, researchers conducted a study among 808 patients. All patients received Herceptin and chemotherapy, and some patients also received pertuzumab.    

• The addition of pertuzumab delayed cancer progression. Survival without cancer progression was 12.4 months among patients treated with only Herceptin and chemotherapy, and 18.5 months among patients treated with Herceptin, chemotherapy, and pertuzumab. 
• The addition of pertuzumab was generally well tolerated by patients, although patients in the pertuzumab group were more likely to experience febrile neutropenia (low-white blood cell count accompanied by fever) and diarrhea. 

These results suggest adding pertuzumab to Herceptin and chemotherapy may improve outcomes among women with metastatic, HER2-positive breast cancer. 

Studies are also exploring the use of pertuzumab in early-stage breast cancer. 

Reference: Baselga J, Cortes J, Kim S-B. Pertuzumab plus trastuzumab plus doxetaxel for metastatic breast cancer. New England Journal of Medicine. Early online publication December 7, 2011.