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

GnRHa + Letrozole in Obese Progestin-insensitive Endometrial Atypical Hyperplasia Patients

Phase 2

Recruiting

Conditions: Obesity
Progesterone Resistance
Atypical Endometrial Hyperplasia

Interventions: Drug: GnRH antagonist
Drug: Letrozole 2.5mg

First Posted Date: 2024-04-30

Last Posted Date: 2024-08-01

Lead Sponsor: Xiaojun Chen

Target Recruit Count: 29

Registration Number: NCT06390904

Locations: 🇨🇳
Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China
🇨🇳
Tenth People's Hospital of Tongji University, Shanghai, Shanghai, China

Saruparib (AZD5305) Plus Camizestrant Compared With CDK4/6 Inhibitor Plus Endocrine Therapy or Plus Camizestrant in HR-Positive, HER2-Negative (IHC 0, 1+, 2+/ ISH Non-amplified), BRCA1, BRCA2, or PALB2m Advanced Breast Cancer

Phase 3

Recruiting

Conditions: Advanced Breast Cancer

Interventions: Drug: Saruparib (AZD5305)
Drug: Camizestrant
Drug: Abemaciclib
Drug: Ribociclib
Drug: Palbociclib
Drug: Fulvestrant
Drug: Letrozole
Drug: Anastrozole
Drug: Exemestane

First Posted Date: 2024-04-24

Last Posted Date: 2025-05-15

Lead Sponsor: AstraZeneca

Target Recruit Count: 500

Registration Number: NCT06380751

Locations: 🇬🇧
Research Site, Taunton, United Kingdom

GnRHa + Letrozole in Obese Progestin-insensitive Endometrial Cancer Patients

Phase 2

Recruiting

Conditions: Atypical Endometrial Hyperplasia
Progesterone Resistance
Obesity
Endometrial Neoplasms

Interventions: Drug: GnRH antagonist
Drug: Letrozole 2.5mg

First Posted Date: 2024-04-23

Last Posted Date: 2024-08-01

Lead Sponsor: Xiaojun Chen

Target Recruit Count: 29

Registration Number: NCT06379113

Locations: 🇨🇳
Tenth People's Hospital of Tongji University, Shanghai, Shanghai, China
🇨🇳
Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China

Letrozole Alone Protocol Versus Using Letrozole and HCG Protocol

Phase 1

Completed

Conditions: PCOS (Polycystic Ovary Syndrome) of Bilateral Ovaries

Interventions: Drug: Letrozole tablets

First Posted Date: 2024-04-16

Last Posted Date: 2024-04-16

Lead Sponsor: Egymedicalpedia

Target Recruit Count: 132

Registration Number: NCT06367712

Locations: 🇪🇬
Ahmed Maher Teaching Hospital, Cairo, Egypt

ALPINE: Maintenance Letrozole/Abemaciclib Vs Pembrolizumab

Phase 2

Recruiting

Conditions: Endometrial Cancer
Recurrent Endometrial Cancer
TP53

Interventions: Drug: Abemaciclib
Drug: Pembrolizumab
Drug: Letrozole

First Posted Date: 2024-04-15

Last Posted Date: 2024-10-31

Lead Sponsor: Dana-Farber Cancer Institute

Target Recruit Count: 76

Registration Number: NCT06366347

Locations: 🇺🇸
Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
🇺🇸
Brigham and Women's Hospital, Boston, Massachusetts, United States
🇺🇸
Dana-Farber Cancer Institute, Boston, Massachusetts, United States

and more 3 locations

Use of Letrozole for Ectopic Pregnancy

Phase 4

Recruiting

Conditions: Ectopic Pregnancy

Interventions: Drug: Methotrexate Sodium
Drug: Letrozole tablets

First Posted Date: 2024-04-09

Last Posted Date: 2024-04-09

Lead Sponsor: Hospital de Clinicas de Porto Alegre

Target Recruit Count: 130

Registration Number: NCT06354439

Locations: 🇧🇷
Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil

Breast Cancer & Antiestrogenic Therapy & Brain

Not yet recruiting

Conditions: Breast Cancer Female
Healthy Female
Menopause
Anti-estrogenic Therapy

Interventions: Drug: Tamoxifen
Drug: Letrozole
Drug: Letrozole + GnRH

First Posted Date: 2024-04-04

Last Posted Date: 2024-04-04

Lead Sponsor: International Research Training Group 2804

Target Recruit Count: 180

Registration Number: NCT06346457

Locations: 🇩🇪
University of Tuebingen; Department of Psychiatry & Psychotherapy Tuebingen, Tuebingen, BW, Germany

Assessing the Efficacy and Safety of Anti-HER2 Therapy in Nigerian Women With HER2+ Breast Cancer Before and After Surgery

Phase 2

Not yet recruiting

Conditions: Human Epidermal Growth Factor 2 Negative Carcinoma of Breast
HER2-positive Breast Cancer
Breast Cancer

Interventions: Drug: Trastuzumab emtansine
Drug: Pertuzumab Injection
Drug: Docetaxel
Drug: Tamoxifen
Drug: Letrozole
Drug: Goserelin

First Posted Date: 2024-04-04

Last Posted Date: 2025-05-06

Lead Sponsor: University of Chicago

Target Recruit Count: 74

Registration Number: NCT06348134

Locations: 🇳🇬
Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Osun, Nigeria
🇺🇸
University of Chicago, Chicago, Illinois, United States