Letrozole is an aromatase inhibitor and antiestrogen used mainly for hormone receptor-positive breast cancer in postmenopausal women. It is marketed under the brand name Femara and used in adjuvant, extended adjuvant, and advanced disease settings. The U.S. approval history begins in the 1990s.
Multiple phase 3 breast cancer trials reported significant findings in early 2026, including positive results for novel therapies across different subtypes. Key data includes progression-free survival benefits for palbociclib in HR-positive, HER2-positive advanced breast cancer and investigations of antibody-drug conjugates and combination therapies. Full trial findings are expected to be presented at upcoming medical meetings.
The FDA has accepted Roche's new drug application for giredestrant plus everolimus to treat ER-positive, HER2-negative, ESR1-mutated advanced breast cancer following prior endocrine therapy, with a decision expected by December 18, 2026.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT07604571 |
Study of IEV407 as Single Agent or in Combination in Patients With Advanced HR+/HER2- Breast Cancer |
NOT_YET_RECRUITING | PHASE1 |
| NCT07604272 |
Reversing InGuinal Hernia Trial: The Evaluation of Sex Hormones to Reverse Inguinal Hernias in Males |
NOT_YET_RECRUITING | PHASE1 |
| NCT07570966 |
Study of ERW316 as a Single Agent or in Combination With Endocrine Therapy in Patients With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors |
NOT_YET_RECRUITING | PHASE1/PHASE2 |
| NCT07492641 |
BGB-43395 Plus Letrozole Versus CDK4/6i Plus Letrozole for Patients With Advanced or Metastatic HR+/HER2- Breast Cancer Who Have Not Received Prior Treatment for Advanced or Metastatic Disease |
RECRUITING | PHASE3 |
| NCT07492394 |
Dalpiciclib With or Without Entinostat and Letrozole in HR+/HER2- Early Breast Cancer |
RECRUITING | PHASE2 |
| NCT07394946 |
Neoadjuvant Letrozole in Postmenopausal Women With Hormone Receptor-Positive, HER2-Negative, Node Positive, Early-Stage Breast Cancer. |
NOT_YET_RECRUITING | PHASE2 |
| NCT07391774 |
Testing Whether Hormone Therapy With Ribociclib is as Effective as Chemotherapy Followed by Hormone Therapy With Ribociclib for the Treatment of High Anatomic Stage Breast Cancer With Low Recurrence Risk, The RxFINE-Low Trial |
NOT_YET_RECRUITING | PHASE3 |
| NCT07305246 |
Clinical Study of SHR-A1811 With or Without Letrozole in Neoadjuvant Therapy for Early-Stage HR-Positive, HER2-Low Breast Cancer |
NOT_YET_RECRUITING | PHASE2 |
| NCT07288359 |
Study of GVV858 as a Single Agent or in Combination With Endocrine Therapy in Patients With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors |
RECRUITING | PHASE1/PHASE2 |
| NCT07183787 |
Letrozole vs Danazol for Endometriosis-Related Pain: Randomized Trial |
COMPLETED | PHASE2 |
