A phase III clinical trial sponsored by Genentech using a combination of chemotherapy drugs showed unprecedented results in patients with metastatic HER2-positive breast cancer. The outcome of this study is published in the February issue of the prestigious New England Journal of Medicine. The trial enrolled over 800 patients with metastatic HER2-positive breast cancer and randomly assigned them to treatment group (pertuzumab + trastuzumab + docetaxel) or control group (placebo + trastuzumab + docetaxel). The treatment group extended lives by close to 16 months compared to the control group, a result that is so impressive that “doctors have rushed to make it standard therapy”. In addition, pertuzumab treatment group did not present more side effects in comparison to the control group.
Pertuzumab (Perjeta) and trastuzumab (Herceptin) are both humanized monoclonal antibodies developed by Genentech to combat HER2-positive cancer cells. These two antibodies target different HER2 epitopes, consequently the combination of these two antibodies results in more comprehensive signaling blockade. Preclinical experiments showed that combining pertuzumab and trstuzumab led to greater activity than that with either antibody alone. Importantly, combination therapy with these two antibodies and docetaxel resulted in higher efficacy among patients receiving neoadjuvant therapy in another clinical trial, which provided the basis for Perjeta’s first FDA approval in 2013 for use in combination with Herceptin and docetaxel in patients with HER2-positive early breast cancer. With this exciting and unprecedented result, Perjeta and Herceptin combination is poised to become the most powerful targeted therapy for HER2-positive cancers, a type of cancer notorious for aggressiveness and therapy-resistance.
Genentech, based in San Francisco, California is a member of the Roche Group. HER2 (human epidermal growth factor receptor 2) is an oncogene and it is over-expressed in about 20% breast cancers. Breast cancer in women is the second most common type of cancer in the US. According to the American Cancer Society, about 231,840 new cases of invasive breast cancer will be diagnosed in women and about 40,290 women will die from breast cancer in 2015 in the US. Worldwide, breast is one of the 5 most common sites diagnosed with cancer.