Roche announced that data from a new study show that the addition of Herceptin (trastuzumab) to the hormonal therapy, Arimidex (anastrozole), increases the length of time that patients live without their cancer progressing (progression-free survival) for patients whose advanced breast cancer is hormone receptor-positive, as well as HER2-positive.
Hormone receptor-positive breast cancer affects two-thirds of patients with breast cancer and is typically considered 'lower-risk' due to successful treatment with hormonal therapies. However, up to a quarter of these breast cancers are also HER2-positive, an aggressive form of the disease that requires special and immediate attention because the tumours are fast-growing and there is a higher likelihood of relapse. This was the first randomised study in this specific subset of 'co-positive' patients, whose prognosis has been uncertain thus far.
Eduard Holdener, global head of Roche Pharma development said, "We are glad to learn from this study that the combination therapy offers a new treatment regimen for these breast cancer patients who suffer from an extremely aggressive form of the disease. We will now work with trial investigators to analyse the full set of data from this trial, and submit it for presentation at an upcoming medical meeting in the second half of 2006. We will start preparations to file these data with health authorities around the world."
To date, over 230,000 patients with HER2-positive breast cancer have been treated with Herceptin worldwide. Herceptin consistently benefits patients regardless of whether it is given in the early stage or advanced settings, or whether it is in combination with chemotherapy, hormonal therapy, or as a single agent.
In HER2-positive breast cancer, increased quantities of the HER2 protein are present on the surface of the tumour cells. This is known as 'HER2 positivity.' High levels of HER2 are present in a particularly aggressive form of the disease which responds poorly to chemotherapy. Research shows that HER2-positivity affects approximately 20% - 30%4 of women with breast cancer.
Herceptin is a humanised antibody, designed to target and block the function of HER2, a protein produced by a specific gene with cancer-causing potential. In addition to its efficacy in the early-stage breast cancer setting, Herceptin also has demonstrated improved survival in the advanced (metastatic) setting, where its addition to chemotherapy allows patients to live up to one-third longer than chemotherapy alone.
Herceptin received approval in the European Union in May 2006 for use in early-stage HER2-positive patients following standard chemotherapy.
Herceptin is marketed in the United States by Genentech, in Japan by Chugai and internationally by Roche. Since 1998, Herceptin has been used to treat over 230,000 HER2-positive breast cancer patients worldwide.