Letrozole
Estrogen-Receptor Positive Breast Cancer
Explore 74 assets in Estrogen-Receptor Positive Breast Cancer →Floatz Rating
BB66/100
Confidence
Indicative
Sponsor
National Cancer Institute (NCI)
Modality
Small molecule
Development Phase
Phase 3
Status
Active
Evidence ledger · v0.2
Clinical Evidence
Clinical track record: trial progression, reported outcomes, safety signals, and endpoint quality.
58High confidence
Detailed axis rationale is planned and will be published soon.
| Trial | Phase | Status | N | Primary endpoint | Readout |
|---|---|---|---|---|---|
NCT07391774CT.gov 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 | — | Recruiting | — | — | — |
NCT07085767CT.gov Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer | — | Recruiting | — | — | — |
NCT06346457CT.gov Breast Cancer & Antiestrogenic Therapy & Brain | — | Unknown | — | — | — |
NCT05512364CT.gov Elacestrant for Treating ER+/HER2- Breast Cancer Patients With ctDNA Relapse (TREAT ctDNA) | — | Recruiting | — | — | — |
NCT06065748CT.gov A Study to Evaluate Efficacy and Safety of Giredestrant Compared With Fulvestrant (Plus a CDK4/6 Inhibitor), in Participants With ER-Positive, HER2-Negative Advanced Breast Cancer Resistant to Adjuvant Endocrine Therapy (pionERA Breast Cancer) | — | Recruiting | — | — | — |
NCT06188520CT.gov A First-in-human Dose Escalation and Expansion Study to Evaluate the Safety, and Tolerability of AZD8421 Alone or in Combination in Participants With Selected Advanced or Metastatic Solid Tumors | — | Recruiting | — | — | — |
NCT06016738CT.gov OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer | — | Recruiting | — | — | — |
NCT05826964CT.gov Levels of Circulating Tumor DNA as a Predictive Marker for Early Switch in Treatment for Patients With Metastatic (Stage IV) Breast Cancer | — | Active Not Recruiting | — | — | — |
NCT05163106CT.gov Neoadjuvant Treatment of Locally-advanced Breast Cancer Patients With Ribociclib and Letrozole | — | Completed | — | — | — |
NCT05508906CT.gov Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer | — | Recruiting | — | — | — |
Show 21 more trialsShow fewer
NCT04886531CT.gov Trial of Pre-operative Neratinib and Endocrine Therapy With Trastuzumab in ER-Positive, HER-2 Positive Breast Cancers | — | Recruiting | — | — | — |
NCT06525675CT.gov Study to Evaluate the Extended Overall Survival (OS) Data From PARSIFAL Study (The PARSIFAL-LONG Study) | — | Completed | — | — | — |
NCT04985266CT.gov A Trial of Early Detection of Molecular Relapse With Circulating Tumour DNA Tracking and Treatment With Palbociclib Plus Fulvestrant Versus Standard Endocrine Therapy in Patients With ER Positive HER2 Negative Breast Cancer | — | Recruiting | — | — | — |
NCT04802759CT.gov A Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Participants With Breast Cancer | — | Recruiting | — | — | — |
NCT04551495CT.gov Neoadjuvant Study of Targeting ROS1 in Combination With Endocrine Therapy in Invasive Lobular Carcinoma of the Breast (ROSALINE) | — | Unknown | — | — | — |
NCT04546009CT.gov A Study Evaluating the Efficacy and Safety of Giredestrant Combined With Palbociclib Compared With Letrozole Combined With Palbociclib in Participants With Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer (persevERA Breast Cancer) | — | Active Not Recruiting | — | — | — |
NCT03554044CT.gov T-VEC With Chemotherapy or Endocrine Therapy in Treating Participants With HER2- Negative Breast Cancer | — | Completed | — | — | — |
NCT03691493CT.gov Radiation Therapy, Palbociclib, and Hormone Therapy in Treating Breast Cancer Patients With Bone Metastasis | — | Completed | — | — | — |
NCT03633331CT.gov Palbociclib and Letrozole or Fulvestrant in Treating Patients With Estrogen Receptor Positive, HER2 Negative Metastatic Breast Cancer | — | Completed | — | — | — |
NCT03128619CT.gov Copanlisib, Letrozole, and Palbociclib in Treating Patients With Hormone Receptor Positive HER2 Negative Stage I-IV Breast Cancer | — | Terminated | — | — | — |
NCT02947685CT.gov Randomized, Open Label, Clinical Study of the Targeted Therapy, Palbociclib, to Treat Metastatic Breast Cancer | — | Active Not Recruiting | — | — | — |
NCT02657928CT.gov Ribociclib and Letrozole in Treating Patients With Relapsed ER Positive Ovarian, Fallopian Tube, Primary Peritoneal, or Endometrial Cancer | — | Completed | — | — | — |
NCT02648477CT.gov Pembrolizumab and Doxorubicin Hydrochloride or Anti-Estrogen Therapy in Treating Patients With Triple-Negative or Hormone Receptor-Positive Metastatic Breast Cancer | — | Completed | — | — | — |
NCT02269670CT.gov Phase II Study of Everolimus Beyond Progression | — | Terminated | — | — | — |
NCT02152943CT.gov Everolimus, Letrozole and Trastuzumab in HR- and HER2/Neu-positive Patients | — | Completed | — | — | — |
NCT01791478CT.gov BYL719 and Letrozole in Post-Menopausal Patients With Hormone Receptor-Positive Metastatic Breast Cancer | — | Active Not Recruiting | — | — | — |
NCT02000375CT.gov A Phase II Study Evaluating the Role of Androgen Receptors as Targets for Therapy of Pre-treated Post-menopausal Patients With ER/PgR-negative/AR-positive or ER and/or PgRpositive/ AR-positive Metastatic Breast Cancer (ARTT) | — | Terminated | — | — | — |
NCT01709370CT.gov Letrozole and CDK 4/6 Inhibitor for ER Positive, HER2 Negative Breast Cancer in Postmenopausal Women | — | Unknown | — | — | — |
NCT01368263CT.gov Goserelin and Letrozole or Anastrozole in Premenopausal Patients With Stage II-III Estrogen Receptor-Positive Breast Cancer | — | Terminated | — | — | — |
NCT01208441CT.gov RO4929097 and Letrozole in Treating Post-Menopausal Women With Hormone Receptor-Positive Stage II or Stage III Breast Cancer | — | Terminated | — | — | — |
NCT00338728CT.gov Letrozole and Imatinib Mesylate in Treating Postmenopausal Participants With Estrogen or Progesterone Positive Metastatic Breast Cancer | — | Completed | — | — | — |
Competitive Position
Competitive setting: how crowded the indication is, class-level failures, and timing against rivals.
81High confidence
Detailed axis rationale is planned and will be published soon.
Same indication · Estrogen-Receptor Positive Breast Cancer
| Asset | Sponsor | Phase | Rating |
|---|---|---|---|
| Letrozole (this asset) | National Cancer Institute (NCI) | P3 | BB · 66 |
| Exemestane | National Cancer Institute (NCI) | P4 | BBB |
| Everolimus | UNC Lineberger Comprehensive Cancer Center | P4 | BBB |
| Tamoxifen | Dana-Farber Cancer Institute | P4 | BB |
| Giredestrant | Hoffmann-La Roche | P3 | BB |
| Abemaciclib | Jonsson Comprehensive Cancer Center | P3 | BB |
| Capivasertib | Imperial College London | P2 | BB |
| Palbociclib | Forward Pharmaceuticals Co., Ltd. | P3 | BB |
| Ribociclib | National Cancer Institute (NCI) | P3 | BB |
+42 more in the Estrogen-Receptor Positive Breast Cancer cohort
Other indications for Letrozole
| Indication | Sponsor | Phase | Rating |
|---|---|---|---|
| Infertility Disorder | — | P4 | BBB · 79 |
| Anovulation | — | P4 | BBB · 78 |
| Invasive Breast Carcinoma | — | P4 | BBB · 74 |
Scientific Foundation
Strength of the underlying biology: target validation, tractability, modality fit, and how related mechanisms have fared.
NR
Planned for methodology v0.2.
Development Feasibility
How realistically the program can be executed, drawing on modality precedent, enrollment dynamics, and sponsor delivery.
NR
Planned for methodology v0.2.
Commercial Opportunity
Commercial prize: addressable population, unmet need, and the value case for the indication.
NR
Planned for methodology v0.2.
IP & Exclusivity
Exclusivity position, covering patent protection and freedom-to-operate runway.
NR
Planned for methodology v0.2.
Manufacturing & Supply
Manufacturing and supply readiness, driven by modality process and scale-up risk.
NR
Planned for methodology v0.2.
Related assets
Citation
Floatz Terminal. Letrozole in Estrogen-Receptor Positive Breast Cancer. Methodology v0.2. Rated under v0.2 effective July 8, 2026. Last refreshed July 8, 2026. Accessed July 14, 2026. https://terminal.floatz.ai/assets/letrozole-estrogen-receptor-positive-breast-cancer
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