Therapy of metastatic breast cancer with humanized antibodies against the HER2 receptor protein

The HER2 protein, a member of the epidermal growth factor family, is encode d by the protooncogene c-erbB-2. Its overexpression, occurring in approxima tely one-third of all breast carcinomas, is associated with a poor prognosi s. A humanized mouse antibody against HER, has been developed by genetic en gineering. Here an unspecific human IgG was connected to the recognizing mo use IgG fragment. The allergization typical for allogeneic antibodies does not take place in this context. The effectiveness of this antibody has been confirmed by two international prospective phase III trials that tested it alone and combined with chemotherapy. Both modes of application increased the response rates and the time to progression. Side-effects were rare exce pt for a high rate of cardiac dysfunction when the antibody was combined wi th anthracyclines. The effectiveness and negligible side-effects of the chi meric antibody against HER2 (Herceptin) render it a valuable tool in the tr eatment of breast cancer.