Letrozole

Generic Name: Letrozole

Brand Names: Femara, Kisqali Femara Co-pack

Drug Type: Small Molecule

Chemical Formula: C_₁₇H_₁₁N_₅

CAS Number: 112809-51-5

Unique Ingredient Identifier: 7LKK855W8I

Background: Letrozole, or CGS 20267, is an oral non-steroidal type II aromatase inhibitor first described in the literature in 1990. It is a third generation aromatase inhibitor like exemestane and anastrozole, meaning it does not significantly affect cortisol, aldosterone, and thyroxine.

Letrozole was granted FDA approval on 25 July 1997.

Indication: Letrozole is indicated to treat postmenopausal women with hormone receptor (HR) positive early breast cancer, postmenopausal women with early breast cancer who have periviously been treated with tamoxifen, and postmenopausal women with HR+ or unknown advanced breast cancer. Letrozole, given with ribociclib, is indicated to treat pre, peri, and postmenopausal women with HR+ and human epidermal growth factor 2 (HER2) negative advanced or metastatic breast cancer.

Associated Conditions: Advanced Breast Cancer, Anovulatory cycle, Epithelial Ovarian Cancer, HR+, HER2-, Advanced Breast Cancer, Stage I Breast Cancer, Metastatic HR + HER2 - breast cancer

Associated Therapies: -

Clinical Trials

Letrozole in Breast Cancer Who Have Received 5 Years of Aromatase Inhibitor Therapy

Phase 3

Completed

Conditions: Breast Cancer

Interventions: Other: placebo
Drug: letrozole

First Posted Date: 2008-09-18

Last Posted Date: 2023-08-25

Lead Sponsor: Canadian Cancer Trials Group

Target Recruit Count: 1918

Registration Number: NCT00754845

Locations: 🇨🇦
CancerCare Manitoba, Winnipeg, Manitoba, Canada
🇨🇦
Lakeridge Health Oshawa, Oshawa, Ontario, Canada
🇨🇦
Niagara Health System, St. Catharines, Ontario, Canada

and more 40 locations

A Study for Safety and Effectiveness of IMC-A12 by Itself or Combined With Antiestrogens to Treat Breast Cancer

Phase 2

Completed

Conditions: Metastatic Breast Cancer

Interventions: Biological: IMC-A12 (cixutumumab)
Drug: tamoxifen
Drug: Anastrozole
Drug: Letrozole
Drug: Exemestane
Drug: Fulvestrant

First Posted Date: 2008-08-06

Last Posted Date: 2018-06-06

Lead Sponsor: Eli Lilly and Company

Target Recruit Count: 93

Registration Number: NCT00728949

Locations: 🇺🇸
ImClone Investigational Site, Nashville, Tennessee, United States

Study Of Letrozole With Or Without Palbociclib (PD-0332991) For The First-Line Treatment Of Hormone-Receptor Positive Advanced Breast Cancer

Phase 2

Completed

Conditions: Breast Cancer

Interventions: Drug: letrozole
Drug: PD 0332991

First Posted Date: 2008-07-24

Last Posted Date: 2019-11-04

Lead Sponsor: Pfizer

Target Recruit Count: 177

Registration Number: NCT00721409

Locations: 🇺🇸
Central Hematology Oncology Medical group Inc., Alhambra, California, United States
🇺🇸
TORI -US Central Administration (Regulatory Management), Los Angeles, California, United States
🇺🇸
TORI -US Central Administration, Los Angeles, California, United States

and more 87 locations

Effect of Aromatase Inhibitor Therapy on Blood Vessel Function in Postmenopausal Women With Breast Cancer

Completed

Conditions: Breast Cancer

Interventions: Procedure: assessment of therapy complications
Drug: anastrozole
Drug: exemestane
Drug: letrozole

First Posted Date: 2008-07-22

Last Posted Date: 2024-01-02

Lead Sponsor: Mayo Clinic

Target Recruit Count: 109

Registration Number: NCT00719966

Locations: 🇺🇸
Mayo Clinic, Rochester, Minnesota, United States

Pregnancy in Polycystic Ovary Syndrome II

Phase 3

Completed

Conditions: Polycystic Ovary Syndrome
Pregnancy

Interventions: Drug: Clomiphene citrate
Drug: Letrozole

First Posted Date: 2008-07-21

Last Posted Date: 2018-06-14

Lead Sponsor: Yale University

Target Recruit Count: 750

Registration Number: NCT00719186

Locations: 🇺🇸
Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States
🇺🇸
University of Colorado, Aurora, Colorado, United States
🇺🇸
Yale University, New Haven, Connecticut, United States

and more 9 locations

BIBW 2992 and Letrozole in Hormonoresistant Metastatic Breast Cancer

Phase 2

Completed

Conditions: Breast Neoplasms

Interventions: Drug: BIBW 2992
Drug: Letrozole

First Posted Date: 2008-07-02

Last Posted Date: 2013-12-30

Lead Sponsor: Boehringer Ingelheim

Target Recruit Count: 28

Registration Number: NCT00708214

Locations: 🇫🇷
1200.5.3306A Boehringer Ingelheim Investigational Site, Caen Cedex, France
🇫🇷
1200.5.3304A Boehringer Ingelheim Investigational Site, Nice Cedex 2, France
🇫🇷
1200.5.3302A Boehringer Ingelheim Investigational Site, Saint Cloud, France

and more 2 locations

Randomized Phase II Trial of Letrozole With or Without Dasatinib as First and Second-line Treatment for Hormone Receptor-positive, HER2-negative Post-menopausal Breast Cancer That is Unresectable, Locally Recurrent or Metastatic

Phase 2

Completed

Conditions: Metastatic Breast Cancer

Interventions: Drug: Dasatinib
Drug: Letrozole

First Posted Date: 2008-06-12

Last Posted Date: 2016-06-13

Lead Sponsor: Bristol-Myers Squibb

Target Recruit Count: 120

Registration Number: NCT00696072

Locations: 🇺🇸
Florida Cancer Institute - New Hope, Hudson, Florida, United States
🇺🇸
Arizona Oncology Associates D.B.A. Hematology Oncology, Tucson, Arizona, United States
🇺🇸
Central Indiana Cancer Centers, Carmel, Indiana, United States

and more 20 locations

Rheumatological Evaluation of Anastrozole and Letrozole as Adjuvant Treatment in Post-menopausal Women With Breast Cancer

Phase 4

Completed

Conditions: Breast Cancer

Interventions: Drug: letrozole

First Posted Date: 2008-06-03

Last Posted Date: 2021-06-09

Lead Sponsor: Novartis Pharmaceuticals

Target Recruit Count: 261

Registration Number: NCT00688909

Locations: 🇺🇸
Tenessee Oncology, Nashville, Tennessee, United States
🇺🇸
Cancer Care of Kansas, Wichita, Kansas, United States
🇺🇸
Augusta Oncology, Augusta, Georgia, United States

and more 45 locations