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

Study of Breast Cancer Prevention by Letrozole in High Risk Women

Phase 2

Completed

Conditions: Breast Cancer

Interventions: Drug: Placebo
Drug: Letrozole

First Posted Date: 2007-12-24

Last Posted Date: 2023-06-12

Lead Sponsor: Carol Fabian, MD

Target Recruit Count: 55

Registration Number: NCT00579826

Locations: 🇺🇸
University of Kansas Medical Center, Kansas City, Kansas, United States

Sorafenib and Letrozole, Anastrozole, or Exemestane in Treating Postmenopausal Women With Estrogen Receptor-Positive and/or Progesterone Receptor-Positive Metastatic Breast Cancer

Phase 2

Terminated

Conditions: Breast Cancer

Interventions: Drug: anastrozole
Drug: exemestane
Drug: letrozole
Other: placebo
Drug: sorafenib tosylate

First Posted Date: 2007-12-14

Last Posted Date: 2016-02-05

Lead Sponsor: Mayo Clinic

Target Recruit Count: 4

Registration Number: NCT00573755

Locations: 🇺🇸
Mayo Clinic in Arizona, Scottsdale, Arizona, United States
🇺🇸
Mayo Clinic in Florida, Jacksonville, Florida, United States
🇺🇸
Mayo Clinic, Rochester, Minnesota, United States

Mid-luteal Phase Synchronization of Ovarian Folliculogenesis in Women

Not Applicable

Completed

Conditions: Ovarian Follicle

Interventions: Drug: Marvelon
Drug: Letrozole
Drug: Nuvaring

First Posted Date: 2007-11-29

Last Posted Date: 2010-04-22

Lead Sponsor: University of Saskatchewan

Target Recruit Count: 41

Registration Number: NCT00565240

Locations: 🇨🇦
Royal University Hospital, Saskatoon, Saskatchewan, Canada

Letrozole in Preventing Cancer in Postmenopausal Women Who Have Received 4-6 Years of Hormone Therapy for Hormone Receptor-Positive, Lymph Node-Positive, Early-Stage Breast Cancer

Phase 3

Completed

Conditions: Breast Cancer

Interventions: Drug: Letrozole

First Posted Date: 2007-11-04

Last Posted Date: 2020-03-11

Lead Sponsor: ETOP IBCSG Partners Foundation

Target Recruit Count: 4884

Registration Number: NCT00553410

Locations: 🇨🇭
Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
🇦🇹
Innsbruck Universitaetsklinik, Innsbruck, Austria
🇺🇸
Dana-Farber/Harvard Cancer Center at Dana-Farber Cancer Institute, Boston, Massachusetts, United States

and more 160 locations

Intermittent Letrozole Therapy in Postmenopausal Women With Metastatic Breast Cancer

Phase 2

Terminated

Conditions: Breast Cancer

Interventions: Drug: Letrozole

First Posted Date: 2007-10-26

Last Posted Date: 2017-03-22

Lead Sponsor: Massachusetts General Hospital

Target Recruit Count: 3

Registration Number: NCT00549822

Locations: 🇺🇸
Dana-Farber Cancer Institute, Boston, Massachusetts, United States
🇺🇸
Massachusetts General Hospital, Boston, Massachusetts, United States

Bevacizumab + Endocrine Treatment vs Endocrine Treatment as First Line in Postmenopausal Women

Phase 3

Completed

Conditions: Breast Cancer

Interventions: Drug: Letrozole
Drug: Bevacizumab
Drug: Fulvestrant

First Posted Date: 2007-10-17

Last Posted Date: 2023-03-31

Lead Sponsor: Spanish Breast Cancer Research Group

Target Recruit Count: 380

Registration Number: NCT00545077

Locations: 🇩🇪
Universitätsklinikum Essen, Essen, Germany
🇩🇪
Klinikum Bayreuth, Bayreuth, Germany
🇩🇪
Universitätsklinikum Charité, Berlin, Germany

and more 65 locations

Study of Anastrozole, Letrozole, or Exemestane With or Without Tamoxifen in Treating Postmenopausal Women With Hormone-Responsive Breast Cancer That Has Been Completely Removed By Surgery

Phase 3

Conditions: Breast Cancer

Interventions: Drug: exemestane
Drug: letrozole
Drug: anastrozole
Drug: tamoxifen citrate

First Posted Date: 2007-10-08

Last Posted Date: 2020-02-07

Lead Sponsor: Gruppo Italiano Mammella (GIM)

Target Recruit Count: 3697

Registration Number: NCT00541086

Locations: 🇮🇹
Federico II University Medical School, Naples, Italy
🇮🇹
Istituto Nazionale per lo Studio e la Cura dei Tumori, Naples, Italy
🇮🇹
Seconda Universita di Napoli, Naples, Italy

and more 2 locations