Tamoxifen

Generic Name: Tamoxifen

Brand Names: Soltamox

Drug Type: Small Molecule

Chemical Formula: C_₂₆H_₂₉NO

CAS Number: 10540-29-1

Unique Ingredient Identifier: 094ZI81Y45

Background: Tamoxifen is a non-steroidal antiestrogen used to treat estrogen receptor positive breast cancers as well as prevent the incidence of breast cancer in high risk populations. Tamoxifen is used alone or as an adjuvant in these treatments. Tamoxifen may no longer be the preferred treatment for these types of cancers as patients generally have better survival, side effect profiles, and compliance with anastrozole.

Tamoxifen was granted FDA approval on 30 December 1977.

Indication: Tamoxifen is indicated to treat estrogen receptor positive metastatic breast cancer in adults, as an adjuvant in the treatment of early stage estrogen receptor positive breast cancer in adults, to reduce the risk of invasive breast cancer after surgery and radiation in adult women with ductal carcinoma in situ.

Associated Conditions: Breast Cancer, Contralateral Breast Cancer, Desmoid Tumor, Early Stage Estrogen Receptor (ER) Positive Breast Cancer, Gynecomastia, Invasive Breast Cancer, Ovarian Cancer, Puberty, Precocious, Metastatic Estrogen Receptor Positive Breast Cancer

Associated Therapies: Ovulation induction therapy

Clinical Trials

A Study Evaluating the Efficacy and Safety of Giredestrant Plus Everolimus Compared With the Physician's Choice of Endocrine Therapy Plus Everolimus in Participants With Estrogen Receptor-Positive, HER2-Negative, Locally Advanced or Metastatic Breast Cancer (evERA Breast Cancer)

Phase 3

Active, not recruiting

Conditions: Estrogen Receptor (ER)-Positive, HER2-negative, Locally Advanced or Metastatic Breast Cancer

Interventions: Drug: Giredestrant
Drug: Exemestane
Drug: Fulvestrant
Drug: Everolimus
Drug: LHRH Agonist
Drug: Tamoxifen
Drug: Dexamethasone Mouth Rinse

First Posted Date: 2022-04-01

Last Posted Date: 2025-04-15

Lead Sponsor: Genentech, Inc.

Target Recruit Count: 320

Registration Number: NCT05306340

Locations: 🇯🇵
Nagoya University Hospital, Aichi, Japan
🇿🇦
Medical Oncology Centre of Rosebank, Johannesburg, South Africa
🇪🇸
Complejo Hospitalario Universitario A Coruña (CHUAC, Materno Infantil), Oncología, La Coruña, LA Coruna, Spain

and more 175 locations

Roll-over Study to Allow Continued Access to Ribociclib

Phase 4

Recruiting

Conditions: Metastatic Breast Cancer

Interventions: Drug: Ribociclib
Drug: Letrozole
Drug: Anastrozole
Drug: Goserelin
Drug: Tamoxifen
Drug: Fulvestrant

First Posted Date: 2021-12-17

Last Posted Date: 2025-05-15

Lead Sponsor: Novartis Pharmaceuticals

Target Recruit Count: 137

Registration Number: NCT05161195

Locations: 🇺🇸
University Hospitals of Cleveland Seidman Cancer Center, Cleveland, Ohio, United States
🇺🇸
Oklahoma Cancer Specialists and Research Institute, Tulsa, Oklahoma, United States
🇺🇸
Millennium Research Clin Develop, Houston, Texas, United States

and more 14 locations

Tamoxifen and SUBA-Itraconzole Combination Testing in Ovarian Cancer

Phase 1

Active, not recruiting

Conditions: Ovarian Cancer

Interventions: Drug: SUBA-itraconazole
Drug: Tamoxifen

First Posted Date: 2021-12-14

Last Posted Date: 2025-05-15

Lead Sponsor: Anthony Joshua, FRACP

Target Recruit Count: 44

Registration Number: NCT05156892

Locations: 🇦🇺
Kinghorn Cancer Centre, St. Vincent's Hospital, Sydney, New South Wales, Australia

Neoadjuvant Endocrine Therapy in ER-positive, HER2-negative Early Stage Breast Cancer

Phase 2

Recruiting

Conditions: Node-negative Breast Cancer
Breast Carcinoma
Breast Cancer
HER2-negative Breast Cancer

Interventions: Drug: Anastrozole 1mg
Drug: Letrozole 2.5mg
Drug: Exemestane 25 mg
Drug: Tamoxifen

First Posted Date: 2021-12-09

Last Posted Date: 2025-03-30

Lead Sponsor: Irada Ibrahim-zada

Target Recruit Count: 70

Registration Number: NCT05150652

Locations: 🇺🇸
University of Kentucky Markey Cancer Center, Lexington, Kentucky, United States

Therapeutic Dose Monitoring (TDM) of Tamoxifen

Phase 2

Conditions: Breast Carcinoma
Cancer of Breast
Malignant Neoplasm of Breast
Breast Tumors
Breast Cancer

Interventions: Drug: Tamoxifen 20 mg

First Posted Date: 2021-11-24

Last Posted Date: 2022-05-25

Lead Sponsor: Karolinska University Hospital

Target Recruit Count: 40

Registration Number: NCT05133674

Locations: 🇸🇪
Karolinska University Hospital, Stockholm, Sweden

Neoadjuvant Treatment of Breast Cancer

Not yet recruiting

Conditions: Breast Cancer

Interventions: Drug: Tamoxifen
Drug: Goserelin
Drug: Letrozole 2.5Mg Tab
Drug: Epirubicin
Drug: cyclophosphamide
Drug: Capecitabine
Drug: Docetaxel
Drug: paclitaxel
Drug: trastuzumab
Drug: pertuzumab

First Posted Date: 2021-11-23

Last Posted Date: 2021-11-23

Lead Sponsor: National Institute of Oncology, Hungary

Target Recruit Count: 300

Registration Number: NCT05131893

Locations: 🇭🇺
National Institute of Oncolgy, Budapest, Hungary

Study of Amcenestrant (SAR439859) Versus Tamoxifen for Patients With Hormone Receptor-positive (HR+) Early Breast Cancer, Who Have Discontinued Adjuvant Aromatase Inhibitor Therapy Due to Treatment-related Toxicity

Phase 3

Terminated

Conditions: Breast Cancer

Interventions: Drug: Tamoxifen
Drug: Amcenestrant
Drug: Tamoxifen-matching placebo
Drug: Amcenestrant-matching placebo

First Posted Date: 2021-11-22

Last Posted Date: 2023-06-22

Lead Sponsor: Sanofi

Target Recruit Count: 3

Registration Number: NCT05128773

Locations: 🇨🇳
Investigational Site Number :1561599, Haikou, China
🇨🇱
Investigational Site Number :1521622, Santiago, Reg Metropolitana De Santiago, Chile