Cancer - Tykerb Response

In March 2007, the FDA approved Tykerb® (lapatinib) for use in combination with Xelodar (capecitabine), another cancer drug, for patients with advanced, metastatic breast cancer that is HER2 positive. In the United States, approximately 8,000 to 10,000 women die from metastatic, HER2 positive breast cancer each year. Tykerb combination treatment is indicated for women who have received prior therapy with other cancer drugs, including an anthracycline, a taxane and Herceptin. Because it has a different mechanism of action, Tykerb works in some HER2 positive breast cancers that have been treated with Herceptin and are no longer benefiting from it. With a minority of patients expected to respond to Tykerb, based on studies referenced in the prescribing information, we believe there will be a significant opportunity to stratify patients based on a biomarker-based test that could be used as an indicator of each patient’s likelihood to respond to Tykerb. We are in the planning phase of developing a biomarker for early response to Tykerb. Like our Herceptin response and Avastin response markers, this test would help doctors determine which patients should continue to receive Tykerb and which patients should switch to alternative treatments.