tamoxifen citrate (Tamoxifen)

H. Lee Moffitt Cancer Center and Research Institute · FDA-approved active Small molecule

tamoxifen citrate (Tamoxifen) is a Selective estrogen receptor modulator (SERM) Small molecule drug developed by H. Lee Moffitt Cancer Center and Research Institute. It is currently FDA-approved for Hormone receptor-positive (HR+) breast cancer, adjuvant treatment, Metastatic breast cancer, HR+, Breast cancer risk reduction in high-risk women. Also known as: Nolvadex, Tam, Tamoxifen.

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 (HR+) breast cancer, adjuvant treatment, Metastatic breast cancer, HR+, Breast cancer risk reduction in high-risk women.

At a glance

Generic name	tamoxifen citrate (Tamoxifen)
Also known as	Nolvadex, Tam, Tamoxifen
Sponsor	H. Lee Moffitt Cancer Center and Research Institute
Drug class	Selective estrogen receptor modulator (SERM)
Target	Estrogen receptor alpha (ERα)
Modality	Small molecule
Therapeutic area	Oncology
Phase	FDA-approved

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. In estrogen receptor-positive breast cancers, this blockade halts cell division and can induce apoptosis. Tamoxifen also has partial agonist activity in some tissues, which accounts for its effects on bone density and thromboembolic risk.

Approved indications

• Hormone receptor-positive (HR+) breast cancer, adjuvant treatment
• Metastatic breast cancer, HR+
• Breast cancer risk reduction in high-risk women
• Ductal carcinoma in situ (DCIS)

Common side effects

• Hot flashes
• Vaginal discharge
• Nausea
• Venous thromboembolism (DVT/PE)
• Endometrial cancer
• Vaginal bleeding
• Fatigue
• Mood changes/depression

Key clinical trials

• Acolbifene Versus Low Dose Tamoxifen for the Prevention of Breast Cancer in Premenopausal Women at High Risk for Development of Breast Cancer (PHASE2)
• Finding the Best Tamoxifen Dose for Breast Cancer Risk Reduction in Premenopausal Women, RENAISSANCE Trial (PHASE2)
• Drug Repurposing in Thyroid Carcinoma: a Feasibility Trial (PHASE1)
• Tamoxifen Citrate or Z-Endoxifen Hydrochloride in Treating Patients With Locally Advanced or Metastatic, Estrogen Receptor-Positive, HER2-Negative Breast Cancer (PHASE2)
• A Study of Elacestrant Versus Standard Endocrine Therapy in Women and Men With ER+,HER2-, Early Breast Cancer With High Risk of Recurrence (PHASE3)
• Letrozole After Tamoxifen in Treating Women With Breast Cancer (PHASE3)
• Hormone Therapy With or Without Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Negative Breast Cancer (The TAILORx Trial) (PHASE3)
• Low Dose Tamoxifen With or Without Omega-3 Fatty Acids for Breast Cancer Risk Reduction (PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Source	Used for
ClinicalTrials.gov	Trial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• tamoxifen citrate (Tamoxifen) CI brief — competitive landscape report
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Frequently asked questions about tamoxifen citrate (Tamoxifen)

What is tamoxifen citrate (Tamoxifen)?

tamoxifen citrate (Tamoxifen) is a Selective estrogen receptor modulator (SERM) drug developed by H. Lee Moffitt Cancer Center and Research Institute, indicated for Hormone receptor-positive (HR+) breast cancer, adjuvant treatment, Metastatic breast cancer, HR+, Breast cancer risk reduction in high-risk women.

How does tamoxifen citrate (Tamoxifen) work?

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

What is tamoxifen citrate (Tamoxifen) used for?

tamoxifen citrate (Tamoxifen) is indicated for Hormone receptor-positive (HR+) breast cancer, adjuvant treatment, Metastatic breast cancer, HR+, Breast cancer risk reduction in high-risk women, Ductal carcinoma in situ (DCIS).

Who makes tamoxifen citrate (Tamoxifen)?

tamoxifen citrate (Tamoxifen) is developed and marketed by H. Lee Moffitt Cancer Center and Research Institute (see full H. Lee Moffitt Cancer Center and Research Institute pipeline at /company/h-lee-moffitt-cancer-center-and-research-institute).

Is tamoxifen citrate (Tamoxifen) also known as anything else?

tamoxifen citrate (Tamoxifen) is also known as Nolvadex, Tam, Tamoxifen.

What drug class is tamoxifen citrate (Tamoxifen) in?

tamoxifen citrate (Tamoxifen) belongs to the Selective estrogen receptor modulator (SERM) class. See all Selective estrogen receptor modulator (SERM) drugs at /class/selective-estrogen-receptor-modulator-serm.

What development phase is tamoxifen citrate (Tamoxifen) in?

tamoxifen citrate (Tamoxifen) is FDA-approved (marketed).

What are the side effects of tamoxifen citrate (Tamoxifen)?

Common side effects of tamoxifen citrate (Tamoxifen) include Hot flashes, Vaginal discharge, Nausea, Venous thromboembolism (DVT/PE), Endometrial cancer, Vaginal bleeding.

What does tamoxifen citrate (Tamoxifen) target?

tamoxifen citrate (Tamoxifen) targets Estrogen receptor alpha (ERα) and is a Selective estrogen receptor modulator (SERM).

Related

• Drug class: All Selective estrogen receptor modulator (SERM) drugs
• Target: All drugs targeting Estrogen receptor alpha (ERα)
• Manufacturer: H. Lee Moffitt Cancer Center and Research Institute — full pipeline
• Therapeutic area: All drugs in Oncology
• Indication: Drugs for Hormone receptor-positive (HR+) breast cancer, adjuvant treatment
• Indication: Drugs for Metastatic breast cancer, HR+
• Indication: Drugs for Breast cancer risk reduction in high-risk women
• Also known as: Nolvadex, Tam, Tamoxifen