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Ribociclib + Letrozole OR Fulvestrant
Ribociclib inhibits CDK4/6 to block cell cycle progression, combined with either letrozole (aromatase inhibitor) or fulvestrant (estrogen receptor antagonist) to suppress hormone-driven breast cancer growth.
Ribociclib inhibits CDK4/6 to block cell cycle progression, combined with either letrozole (aromatase inhibitor) or fulvestrant (estrogen receptor antagonist) to suppress hormone-driven breast cancer growth. Used for Hormone receptor-positive, HER2-negative advanced or metastatic breast cancer (first-line or subsequent therapy).
At a glance
| Generic name | Ribociclib + Letrozole OR Fulvestrant |
|---|---|
| Sponsor | SOLTI Breast Cancer Research Group |
| Drug class | CDK4/6 inhibitor + aromatase inhibitor OR estrogen receptor degrader |
| Target | CDK4/6 + aromatase OR estrogen receptor |
| Modality | Small molecule |
| Therapeutic area | Oncology |
| Phase | Phase 3 |
Mechanism of action
Ribociclib is a CDK4/6 inhibitor that prevents phosphorylation of the retinoblastoma protein, halting G1/S cell cycle transition in hormone receptor-positive breast cancer cells. Letrozole blocks aromatase to reduce estrogen synthesis, while fulvestrant degrades the estrogen receptor itself. The combination exploits dual mechanisms: cell cycle arrest plus hormonal suppression.
Approved indications
- Hormone receptor-positive, HER2-negative advanced or metastatic breast cancer (first-line or subsequent therapy)
Common side effects
- Neutropenia
- Leukopenia
- Nausea
- Fatigue
- Diarrhea
- Vomiting
- Anemia
- Arthralgia
Key clinical trials
- Capivasertib+Fulvestrant asTreatment for Locally Advanced(Inoperable) or Metastatic HR+/HER2- Breast Cancer in Chinese Patients (PHASE3)
- Targeted Therapy Directed by Genetic Testing in Treating Patients With Locally Advanced or Advanced Solid Tumors, The ComboMATCH Screening Trial (PHASE2)
- A Study to Evluate Efficacy and Safety of HRS-8080 Combined With Dalpiciclib in Patients With Advanced or Metastatic Breast Cancer Resistant to Adjuvant Endocrine Therapy. (PHASE3)
- 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 (PHASE3)
- Study of ECI830 Single Agent or in Combination in Patients With Advanced HR+/HER2- Breast Cancer and Other Advanced Solid Tumors (PHASE1, PHASE2)
- A Study of LOXO-783 in Patients With Breast Cancer/Other Solid Tumors (PHASE1)
- Efficacy and Safety of Tinengotinib Tablets Combined With Fulvestrant Injection in Patients With HR Positive and HER-2 Negative Recurrent or Metastatic Breast Cancer Who Have Failed Prior Treatment (PHASE2)
- Liquid-biopsy Informed Platform Trial to Evaluate CDK4/6-inhibitor Resistant ER+/HER2- Metastatic Breast Cancer (PHASE2)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
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