News briefs from breast cancer meeting

In further news from the the San Antonio Breast Cancer Symposium (SABCS) that took place in Texas, USA (see also The Pharma Letter December 9), UK pharma giant GlaxoSmithKline (LSE: GSK) presented Phase III trial data showing that Tykerb (lapatinib), currently approved for the treatment of advanced or metastatic breast cancer, in the delayed adjuvant setting in women with HER2 positive breast cancer failed to significantly improve disease-free survival (DFS) compared to placebo.

The primary objective of the study, dubbed TEACH (Tykerb Evaluation After Chemotherapy), was to compare disease-free survival (DFS) between women receiving lapatinib and those on placebo. More than ,3000 women who completed neo-adjuvant or adjuvant chemotherapy, did not receive trastuzumab and did not have evidence of disease were randomized to receive lapatinib or placebo for up to 12 months or until a DFS event, defined as objective disease recurrence, a second primary cancer, contralateral breast cancer or death from any cause.

After a median follow up of four years, DFS events occurred in 13% of patients in the lapatinib arm and 17% of patients in the placebo arm of the trial (Hazard Ratio = 0.83 95% Confidence Interval, 0.70 to 1.00; stratified log-rank 2-sided p=0.053). Therefore, although an improvement in disease-free survival in favor of lapatinib was observed, this result did not meet the pre-specified criteria for statistical significance.