Herceptin trastuzumab: Phase III data

The open-label, international Phase III ALTTO trial in 8,381 patients with HER2-positive early breast cancer showed that adjuvant treatment with oral Tykerb lapatinib plus IV Herceptin trastuzumab missed the primary endpoint of improving DFS vs. Herceptin alone. Specifically, Tykerb plus Herceptin led to a 4-year DFS rate of 88% vs. 86% for Herceptin alone (p=0.048). The primary endpoint was designed to test for superiority of Tykerb plus Herceptin vs. Herceptin alone with a p-value of <=0.025. Additionally, Herceptin followed by Tykerb led to a 4-year DFS rate of 87% vs. 86% for Herceptin alone (p=0.061). The trial was designed to evaluate non-inferiority of Herceptin followed by Tykerb vs. Herceptin alone with a p-value of <=0.025. The most common adverse events reported were diarrhea (75% for Tykerb plus Herceptin vs. 20% for Herceptin alone), rash (55% vs. 20%) and hepatobiliary (23% vs. 16%). The incidence of grade >=3 diarrhea was increased in all Tykerb-containing treatment arms vs. Herceptin alone. Data were presented at the American Society of Clinical Oncology meeting in Chicago. ...