Hot on the heels of positive clinical trial results for a new therapy come the requests for economic information. Decision-makers need such data to determine the potential economic impact of providing the new therapy to patients. This demand for economic data was the challenge facing economists at Hoffmann-La Roche in Canada after the presentation of phase III data for trastuzumab at the 1998 ASCO meeting.*To meet this demand, the company developed a model for predicting expenditures for adopting the new monoclonal antibody in the treatment of metastatic breast cancer. The model was presented at EORTC's 2nd European Conference on the Economics of Cancer [Brussels, Belgium; September 2000].*