While awareness and support for breast cancer research is at an all-time high and Canadians "think pink," one-quarter of Canadian women are still not convinced a breast cancer diagnosis may be fatal.2 Yet, breast cancer can be a very aggressive disease and claims the lives of 100 Canadian women every week.3
For women with HER2-postive metastatic (or advanced) breast cancer, a particularly aggressive and hard-to-treat form of the disease,4 a new first-in-class biological therapy has been approved by Health Canada. PERJETA (pertuzumab), in combination with the current standard of care, HERCEPTIN® (trastuzumab) and docetaxel chemotherapy, is approved for the treatment of patients with HER2-positive metastatic breast cancer (mBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease.1
Women with metastatic HER2-positive breast cancer are at an increased risk of their disease worsening, and ultimately death,5,6 and therefore need innovative and effective therapies that will give them more time with family and friends.
According to Dr. Christine Brezden-Masley, medical oncologist and Head of the Division of Hematology-Oncology, St. Michael's Hospital and CLEOPATRA clinical trial investigator, PERJETA represents a substantial advancement in the treatment of HER2-positive metastatic breast cancer. She states: "since the approval of HERCEPTIN over 10 years ago, we have not had a therapy show such significant benefits in extending survival, and with manageable side effects. PERJETA is a unique treatment. It builds on the success of HERCEPTIN and takes it further."
The approval of PERJETA is based on results from the Phase III CLEOPATRA study. In the study, people who received a combination of PERJETA, HERCEPTIN and docetaxel chemotherapy lived a median 6.1 months longer without their cancer getting worse (progression-free survival or PFS) compared to the current standard of care, HERCEPTIN plus docetaxel chemotherapy, alone (median PFS 18.5 months versus 12.4 months; HR=0.62; p<0.0001).1,7
In fact, the combination of PERJETA, HERCEPTIN and docetaxel chemotherapy significantly extended the lives of people with previously untreated HER2-positive metastatic breast cancer (overall survival) compared to HERCEPTIN, docetaxel chemotherapy and placebo. The risk of death was reduced by 34 per cent for people on the PERJETA arm of the study, compared to those who received HERCEPTIN and docetaxel chemotherapy alone (HR=0.66; p=0.0008). At the time of data analysis, median overall survival had not yet been reached because more than half of the patients receiving the PERJETA combination were still alive.8
Betty Power is living with HER2-positive mBC and has been taking PERJETA since August 2012 as part of the CLEOPATRA study. "Having a new treatment option is a huge step for women with metastatic breast cancer," says Ms. Power. "Being in the CLEOPATRA trial gave me access to PERJETA and now that Health Canada has approved it, more women could benefit from it."
The combination of PERJETA, HERCEPTIN and chemotherapy is thought to provide a more comprehensive blockade of HER2 signalling pathways. While HERCEPTIN blocks the "survive and multiply" signals sent by HER2 receptors, PERJETA is designed to prevent the HER2 receptor from pairing or 'dimerizing' with other HER receptors on the surface of cells. This process is believed to play a role in tumour growth and survival. Binding of PERJETA to HER2 may also signal the body's immune system to destroy the cancer cells.
Leger research revealed nearly half of Canadian women did not believe women with advanced breast cancer in Canada have all the treatment options they need.2 This sentiment is shared by patient groups like Rethink Breast Cancer, a breast cancer charity dedicated to boldly and creatively raising awareness of the disease, and who are committed to ensuring all breast cancer patients in Canada receive the best treatments available.
"Until there are no women dying from breast cancer, more treatments are needed," says MJ DeCoteau, Executive Director, Rethink Breast Cancer. "It is so important that new, effective treatments like PERJETA are quickly available for all women with HER2-positive metastatic breast cancer, so they receive the best defence against their disease."
The Canadian Breast Cancer Network (CBCN), a national network of organizations and individuals committed to the best quality of life for all Canadians affected by the disease, agrees. "HER2-positive metastatic breast cancer is an aggressive disease that requires aggressive action," says Cathy Ammendolea, Board Chair at CBCN and breast cancer survivor. "We're pleased Canadian women will have a new option that has been shown to prolong a woman's life, while keeping the disease from advancing."