Exemestane

Exemestane Report

Name: Exemestane Name (English): Exemestane DrugBank ID: DB00990 Type: Small Molecule CAS Number: 107868-30-4

Exemestane is an irreversible, steroidal aromatase inhibitor. It is indicated for the adjuvant treatment of postmenopausal women with estrogen receptor-positive early breast cancer and for the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following anti-estrogen therapy. Exemestane works by binding to and inactivating the aromatase enzyme, which is responsible for the final step in estrogen biosynthesis. This leads to a significant reduction in circulating estrogen levels.

Pharmacokinetics: Exemestane is rapidly absorbed after oral administration, with peak plasma concentrations reached within 2 hours. It is extensively metabolized in the liver, primarily via CYP3A4, and the metabolites are excreted in both urine and feces. The elimination half-life is approximately 9 hours. Food can increase the extent of absorption.

Mechanism of Action: Exemestane is a steroidal aromatase inhibitor. It acts as a false substrate for the aromatase enzyme, leading to its irreversible inactivation. By inhibiting aromatase, exemestane reduces the production of estrogen in postmenopausal women, where the primary source of estrogen is the conversion of androgens to estrogens by aromatase in peripheral tissues.

Indications:

• Adjuvant treatment of postmenopausal women with estrogen receptor-positive early breast cancer, either as initial adjuvant therapy or following 2-3 years of tamoxifen. It is also indicated for extending adjuvant treatment in women who have received 5 years of tamoxifen.
• Treatment of advanced breast cancer in postmenopausal women whose disease has progressed following anti-estrogen therapy. Efficacy has not been demonstrated in patients with estrogen receptor-negative status.