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Tamoxifen alone

Austrian Breast & Colorectal Cancer Study Group · Phase 3 active Small molecule

Tamoxifen is a selective estrogen receptor modulator (SERM) that blocks estrogen binding to its receptor on breast cancer cells, inhibiting their growth.

Tamoxifen is a selective estrogen receptor modulator (SERM) that blocks estrogen binding to its receptor on breast cancer cells, inhibiting their growth. Used for Hormone receptor-positive breast cancer (adjuvant and metastatic), Breast cancer prevention in high-risk women.

At a glance

Generic nameTamoxifen alone
Also known asNolvadex
SponsorAustrian Breast & Colorectal Cancer Study Group
Drug classSelective estrogen receptor modulator (SERM)
TargetEstrogen receptor alpha (ERα)
ModalitySmall molecule
Therapeutic areaOncology
PhasePhase 3

Mechanism of action

Tamoxifen competitively binds to estrogen receptors (ER) on hormone-responsive breast cancer cells, preventing endogenous estrogen from activating these receptors and promoting cell proliferation. By blocking ER signaling, it induces cell cycle arrest and apoptosis in ER-positive breast cancer cells. It has mixed agonist/antagonist activity depending on tissue type, acting as an antagonist in breast tissue but with some agonist effects in other tissues.

Approved indications

Common side effects

Key clinical trials

Primary sources

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