GSK's Tykerb 'to rival Herceptin,' Ph III study

UK drug major GlaxoSmithKline says that its investigational anticancer drug Tykerb (lapatinib ditosylate) increases life expectancy in breast cancer patients who failed treatment with Roche's breakthrough breast cancer drug Herceptin (trastuzumab).

London-headquartered GSK reported late-breaking results from a large, randomized, pivotal Phase III study (EGF100151) of its small-molecule dual kinase inhibitor at the 2006 American Society of Clinical Oncology annual meeting in Atlanta, Georgia, showing that, in combination with another Roche anticancer drug, Xeloda (capecitabine), it nearly doubled time-to-progression versus Xeloda alone (36.9 weeks vs 19.7 weeks; p=0.00032) in women with refractory advanced or metastatic ErbB2 positive breast cancer whose disease had progressed following treatment with Herceptin and other therapies.

A few months ago, GSK stopped enrollment of the study based on the unanimous recommendation of an Independent Data Monitoring Committee because time to disease progression with the regimen exceeded the predefined primary endpoint (Marketletter April 10).