Exemestane.

▴ Exemestane is a steroidal agent which causes inactivation of the aromatase enzyme by binding irreversibly to the substrate binding site. ▴ Oral exemestane 25 mg/day inactivates peripheral aromatase activity (~98% inactivation) and reduces basal plasma estrone, estradiol and estrone sulphate levels by 85 to 95% in postmenopausal women with advanced breast cancer. ▴ Phase II trials indicate that oral exemestane 25 mg/day is an effective second- or third-line agent in the treatment of postmenopausal women with advanced breast cancer (achieving an objective response in up to 28 and 26% of patients, respectively). ▴ Results from a phase III trial indicate that exemestane achieves a similar objective response rate to megestrol as a second-line therapy; however, exemestane achieved a significantly longer duration of overall success, time to disease progression and survival time. ▴ Exemestane is at least as well tolerated as megestrol, but is associated with significantly fewer bodyweight changes, mainly bodyweight gain (≥10%). Other common adverse events are hot flushes, nausea and fatigue. [ABSTRACT FROM AUTHOR]