Tykerb/Tyverb+trastuzumab fails to meet primary endpoint in Phase III Breast Cancer trial - GSK

GlaxoSmithKline has announced that the Phase III study of two anti-HER2 agents, Tykerb/Tyverb (lapatinib) and trastuzumab, did not meet the primary endpoint of improved disease free survival (DFS) compared to single agent therapy with trastuzumab as adjuvant treatment for HER2 positive early Breast Cancer. The results showed that at four years, 88 percent of women lived without their disease returning (4-year DFS) in the lapatinib plus trastuzumab arm and 86 percent in the trastuzumab arm. The 4-year DFS rate for the trastuzumab followed by lapatinib arm was 87 percent compared to 86 percent in the trastuzumab arm.

The safety profile was consistent with the established safety profile of the study drugs, with no new safety signals observed. Adverse events (AEs) more frequently reported in the lapatinib plus trastuzumab arm compared to the trastuzumab arm were diarrhoea (75% vs. 20%), rash (55% vs. 20%) and hepatobiliary (23% vs. 16%). These results were presented at the 50th Annual Meeting of the American Society of Clinical Oncology (ASCO).