Issue link: http://viewer.e-digitaleditions.com/i/85232
UPDATE ON HERCEPTIN IN METASTATIC BREAST CANCER: The COMPLETE trial This study compared Tykerb (lapatinib) and Herceptin both given with chemotherapy as initial treatment for metastatic breast cancer. The study was stopped early as patients on Herceptin did better than those on Tykerb. Patients confirmed as having HER2 positive metastatic breast cancer who received Tykerb progressed (that is, their cancer continued to spread) nearly five months earlier, on average, than in patients who received Herceptin. Patients on Tykerb also had more side effects during treatment than those who received Herceptin with more patients stopping due to side effects. NEW TREATMENTS EMERGING IN 2012: The CLEOPATRA trial This study was reported at the San Antonio Breast Cancer conference at the end of last year. It looked at a new medicine in HER2 breast cancer called Pertuzumab (per-too-zoo-mab). The study showed that when Pertuzumab was added to Herceptin and chemotherapy as initial (first line) treatment of HER2 metastatic breast cancer, it extended the time before the cancer progressed (continued to grow) by six months. On average patients were treated for 18 months before progressing compared to 12 months in patients on Herceptin plus chemotherapy alone. In context, when Herceptin was first introduced it extended time until progression by three - six months. Importantly, there appears to be only a few additional side effects when Pertuzumab is added. This appears to be an important breakthrough for first line treatment of HER2 positive metastatic breast cancer. However overall survival has not yet been reported and longer follow-up will be important. This medicine is not registered or available in New Zealand yet. The EMILIA trial This study reported at the American Society of Clinical Oncology (ASCO) meeting in June. It looked at a new medicine called Trastuzumab Emtansine (em-tan-zine) or T-DM1. T-DM1 is a combination of trastuzumab or Herceptin with emtanzine or DM1. DM1 is a highly potent cytotoxic (kill cells) medicine which is too toxic to give on its own. By attaching the DM1 to HER2 is a receptor that is found on all normal cells and in HER2 positive breast cancer it is found in numbers many times higher than normal cells. Herceptin it can be targeted to the HER2 cancer cells, a bit like a smart bomb. The study compared T-DM1 with the second line metastatic cancer treatment of Tykerb and another chemotherapy medicine called Xeloda (capecitabine). Second line treatments are given only after women have progressed on their initial or first line treatment. The study showed that T-DM1 alone was more effective than Tykerb plus Xeloda. The average time before a women's cancer progressed was increased by three months. Importantly, patients experience few serious side effects on T-DM1. There are currently no funded HER2 targeted agents in New Zealand in second line metastatic breast cancer. T-DM1 is also currently not registered or available in New Zealand. These trials are only a selection of new data in HER2 breast cancer but are those likely to have the biggest impact for patients.