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

Clinical Trials

Efficacy and Safety of Fluzoparib Combined With Adjuvant Endocrine Therapy for HR+/HER2- SNF3-subtype Early Breast Cancer (BCTOP-L-A01)

Phase 3

Recruiting

Conditions: Breast Cancer

Interventions: Drug: Fluzoparib
Drug: Anastrozole
Drug: Letrozole
Drug: Exemestane
Drug: Tamoxifen
Drug: Toremifene
Drug: Abemaciclib
Drug: LHRH agonist

First Posted Date: 2023-06-06

Last Posted Date: 2024-02-08

Lead Sponsor: Fudan University

Target Recruit Count: 766

Registration Number: NCT05891093

Locations: 🇨🇳
Sun Yat-sen University Cancer Center, Guangdong, Guangzhou, China
🇨🇳
Shanghai Sixth People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, Shanghai, China
🇨🇳
Fujian Medical University Union Hospital, Fuzhou, Fujian, China

and more 12 locations

Abemaciclib and Letrozole in Patients with Estrogen Receptor-positive Rare Ovarian Cancer

Phase 2

Recruiting

Conditions: Adult Type Granulosa Cell Tumor
Low Grade Serous Ovarian Carcinoma

Interventions: Drug: Abemaciclib
Drug: Letrozole

First Posted Date: 2023-05-24

Last Posted Date: 2025-03-19

Lead Sponsor: Universitaire Ziekenhuizen KU Leuven

Target Recruit Count: 100

Registration Number: NCT05872204

Locations: 🇧🇪
UZ Gent, Gent, Oost-Vlaanderen, Belgium
🇧🇪
UZ Leuven, Leuven, Vlaams-Brabant, Belgium
🇧🇪
CHU de Liège, Liège, Belgium

and more 9 locations

Study of AVZO-021 in Patients With Advanced Solid Tumors

Phase 1

Recruiting

Conditions: Advanced Solid Tumor
HR+/HER2- Breast Cancer
HR+, HER2-, Advanced Breast Cancer
CCNE1 Amplification
Epithelial Ovarian Cancer
Primary Peritoneal Cancer
Fallopian Tube Cancer
Endometrial Cancer
TNBC - Triple-Negative Breast Cancer

Interventions: Drug: AVZO-021
Drug: Palbociclib
Drug: Fulvestrant
Drug: Letrozole
Drug: Ribociclib
Drug: Abemaciclib
Drug: Carboplatin
Drug: Sacituzumab Govitecan-hziy

First Posted Date: 2023-05-19

Last Posted Date: 2025-04-03

Lead Sponsor: Avenzo Therapeutics, Inc.

Target Recruit Count: 430

Registration Number: NCT05867251

Locations: 🇺🇸
Texas Oncology - DFW, Dallas, Texas, United States
🇺🇸
Yale Cancer Center, New Haven, Connecticut, United States
🇺🇸
Florida Cancer Specialists, Sarasota, Florida, United States

and more 6 locations

A Study of GB491 in Combination With Letrozole in Patients With HR Positive and HER2 Negative Advanced Breast Cancer

Phase 3

Recruiting

Conditions: Breast Cancer

Interventions: Drug: GB491 combined with Letrozole
Drug: Placebo combined with Letrozole

First Posted Date: 2023-05-09

Last Posted Date: 2023-05-09

Lead Sponsor: Genor Biopharma Co., Ltd.

Target Recruit Count: 350

Registration Number: NCT05851014

Locations: 🇨🇳
Xingtai People's Hospital, Xingtai, Hebei, China
🇨🇳
Hubei Cancer Hospital, Wuhan, Hubei, China
🇨🇳
Hunan Cancer Hospital, Changsha, Hunan, China

and more 49 locations

Impact of Co Enzyme Q10 as Adjuvant Therapy to Letrozole on Spermiogram

Phase 2

Completed

Conditions: Male Reproductive Problem
Infertility, Male

Interventions: Drug: Letrozole tablets
Dietary Supplement: Coenzyme Q10 table

First Posted Date: 2023-05-06

Last Posted Date: 2025-02-19

Lead Sponsor: Al-Mustansiriyah University

Target Recruit Count: 74

Registration Number: NCT05847257

Locations: 🇮🇶
specialized center of infertility/ Nahrain University, Baghdad, Iraq

Monotherapy With Letrozole in Tubal Pregnancy

Not Applicable

Completed

Conditions: Tubal Pregnancy Unruptured

Interventions: Drug: MTX as monotherapy
Drug: Letrozole as monotherapy

First Posted Date: 2023-05-03

Last Posted Date: 2023-11-18

Lead Sponsor: Jagiellonian University

Target Recruit Count: 22

Registration Number: NCT05839561

Locations: 🇵🇱
Jagiellonian University Medical College, Department of Gynecology and Obstetrics, Clinic of Gynecological Endocrinology, Krakow, Poland

Phase IIIb Study of Ribociclib + ET in Early Breast Cancer

Phase 3

Recruiting

Conditions: Early Breast Cancer

Interventions: Drug: Ribociclib
Drug: Letrozole
Drug: Ansastrozole
Drug: Goserelin
Drug: Leuprolide
Drug: Exemestane

First Posted Date: 2023-04-24

Last Posted Date: 2025-05-21

Lead Sponsor: Novartis Pharmaceuticals

Target Recruit Count: 1400

Registration Number: NCT05827081

Locations: 🇺🇸
Ocala Research Institute, Inc, Ocala, Florida, United States
🇺🇸
Alaska Oncology and Hematology LLC, Anchorage, Alaska, United States
🇺🇸
Washington Hospital Center, Washington, District of Columbia, United States

and more 7 locations