NCT06120283 · BeOne Medicines
BGB-43395 Alone or as Part of Combination Therapies in Participants With Breast Cancer and Other Advanced Solid Tumors
What this study is about
This is a gradually increasing doses and dose expansion study to compare how well BGB-43395, a selective cyclin-dependent kinase 4 (CDK4) inhibitor, works as treatment given alone or in combination with fulvestrant, letrozole, or elacestrant in participants with hormone receptor positive (HR+) and human epidermal growth factor 2 negative (HER2-) breast cancer (BC) and other advanced solid tumors.
View original scientific description
This is a dose escalation and dose expansion study to compare how well BGB-43395, a selective cyclin-dependent kinase 4 (CDK4) inhibitor, works as monotherapy or in combination with fulvestrant, letrozole, or elacestrant in participants with hormone receptor positive (HR+) and human epidermal growth factor 2 negative (HER2-) breast cancer (BC) and other advanced solid tumors. The main purpose of this study is to explore the recommended dosing for BGB-43395.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Phase 1a (Dose Escalation): Participants with histologically or cytologically confirmed advanced, metastatic, or unresectable solid tumors associated with dependency on CDK4, including HR+ breast cancer, ovarian cancer, endometrial cancer, non-small cell lung cancer, and others. For combination with elacestrant, participants must have received at least 1 prior line of treatment for advanced/metastatic disease including prior endocrine therapy and CDK4/6 inhibitor in either the adjuvant or advanced/metastatic setting.
- Phase 1a Safety Expansion: For combination with fulvestrant in regions where approved and available, participants with HR+ breast cancer must have received at least 1 prior line of treatment including endocrine therapy and a CDK4/6 inhibitor. For combination with letrozole, participants must be CDK4/6 inhibitor treatment naïve and have not received any previous systemic treatment for advanced disease.
- Phase 1b: Participants with HR+/HER2- breast cancer.
- Phase 1b: For combination with fulvestrant, participants with HR+/HER2- breast cancer enrolled in regions where CDK4/6 inhibitors are approved and available must have received 1-2 lines of therapy for advanced/metastatic disease including endocrine therapy and a CDK4/6 inhibitor. Participants can have received up to 2 lines of prior cytotoxic chemotherapy for advanced disease. Prior cytotoxic treatment is prohibited. For combination cohorts with letrozole, participants must be CDK4/6 inhibitor treatment naïve and have not received any previous systemic treatment for advanced disease.
- Stable Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1.
- Female participants with metastatic HR+/HER2- breast cancer must be postmenopausal or receiving ovarian function suppression treatment.
- Adequate organ function without symptomatic visceral disease.
Exclusion criteria
- Known leptomeningeal disease or uncontrolled, untreated brain metastases.
- Any malignancy ≤ 3 years before the first dose of study treatment(s) except for the specific cancer under investigation in this study and any locally recurring cancer that has been treated with curative intent (eg, resected basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the cervix or breast).
- Uncontrolled diabetes.
- Infection requiring systemic antibacterial, antifungal, or antiviral therapy ≤ 28 days before the first dose of study drug(s), or symptomatic COVID-19 infection.
- Participants with untreated chronic hepatitis B or chronic hepatitis B virus (HBV) carriers with HBV DNA ≥ 500 IU/mL (or ≥ 2500 copies/mL) at screening.
- Participants with active hepatitis C infection.
- Prior allogeneic stem cell transplantation, or organ transplantation. Note: Other protocol defined Inclusion/Exclusion criteria may apply.
Where
- Denver, Colorado
- Lake Mary, Florida
- Detroit, Michigan
- St Louis, Missouri
- Durham, North Carolina
- Columbus, Ohio
- Nashville, Tennessee
- Houston, Texas
- Irving, Texas
- San Antonio, Texas
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 10, 2026 · Source of record for eligibility and locations