Pfizer's Aromasin little different to tamoxifen in disease progression for breast cancer patients

Global pharmaceutical behemoth Pfizer announced disappointing results at the San Antonio Breast Cancer Symposium, USA, on Friday from an exploratory analysis of the Intergroup Exemestane Study (IES) at a median follow-up of 91 months in estrogen-receptor positive (ER+) or estrogen-receptor unknown (ER-unknown) women that looked at breast cancer free survival (BCFS) and censored deaths that occurred prior to breast cancer relapse.

These data showed that women who switched to Aromasin (exemestane tablets) after 2.5 years of tamoxifen experienced a 19% reduction in risk of breast cancer recurrence (HR=0.81 95% CI (0.71, 0.92); p<0.001) compared to those who continued on tamoxifen for a full five years of treatment. >

Separately, results from the Tamoxifen, Exemestane, Adjuvant, Multicenter (TEAM) study did not show a difference in disease free survival (DFS) in women who took Aromasin for five years compared to those who switched from tamoxifen to Aromasin after two to three years (HR=0.97 (95% CI 0.88-1.08); P=0.604). However, the company said that data continue to underscore the benefits of Aromasin for postmenopausal women with hormone-receptor positive/unknown early breast cancer.