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Aromasin (exemestane)

Pfizer · FDA-approved active Small molecule

Exemestane irreversibly inhibits aromatase, the enzyme that converts androgens to estrogen in postmenopausal women, thereby reducing circulating estrogen levels.

Exemestane irreversibly inhibits aromatase, the enzyme that converts androgens to estrogen in postmenopausal women, thereby reducing circulating estrogen levels. Used for Hormone receptor-positive breast cancer in postmenopausal women (adjuvant and metastatic settings), Extended adjuvant therapy following tamoxifen in postmenopausal women with early-stage breast cancer.

At a glance

Generic nameAromasin (exemestane)
Also known asAromasin, exemestane
SponsorPfizer
Drug classAromatase inhibitor (steroidal)
TargetAromatase (CYP19A1)
ModalitySmall molecule
Therapeutic areaOncology
PhaseFDA-approved

Mechanism of action

Aromatase is the primary source of estrogen production in postmenopausal women, and many breast cancers depend on estrogen for growth. By irreversibly binding to and inactivating aromatase, exemestane depletes systemic estrogen, starving estrogen-dependent breast cancer cells. This mechanism is distinct from reversible aromatase inhibitors and represents a steroidal approach to hormone deprivation therapy.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results