Herceptin® (trastuzumab) is a monoclonal antibody therapy that directly targets the HER2 protein of breast tumors and offers survival benefit for women with breast cancer that over-expresses HER2. The combined results of two large clinical trials indicate that adding trastuzumab to standard chemotherapy for early stage HER2-positive breast cancer reduced the recurrence rate and mortality by up to 52%, when compared to chemotherapy alone.
In 2006, the US Food and Drug Administration (FDA) approved trastuzumab for all HER2-positive breast cancers. HER2 over expression detected by IHC, or another method, is required before receiving trastuzumab treatment. Trastuzumab therapy is typically 12 months in duration and the drug cost for 52 weeks is approximately $100,000, with the additional costs of a subsequent 9-12 month post treatment of intravenous chemotherapy. Providing treatment to contraindicated patients burdens them with additional, unnecessary treatment costs if they will not improve with trastuzumab treatment. Administration to contraindicated patients also exposes them to the potential side effect of cardiac toxicity. Thus, due to the high costs associated with treatment and the risk of cardiac toxicity, it is crucial that HER2 results are extremely accurate.