Back to search results

BGB-43395 for Advanced Solid Tumors and Breast Cancer

This study is testing a new drug, BGB-43395, by itself or with other standard treatments like Fulvestrant, Letrozole, or Elacestrant. BGB-43395 works by targeting CDK4, a protein involved in cancer growth. You might be able to join if you have advanced solid tumors, including hormone receptor-positive (HR+) breast cancer, ovarian cancer, endometrial cancer, or non-small cell lung cancer, and your cancer depends on CDK4. The main goal is to find the safest and most effective dose of BGB-43395. Researchers will also be looking at any side effects you might experience. This study is currently recruiting participants.

Study design
This is a dose escalation and dose expansion study, meaning it will first find the right dose and then test it in more people. It plans to enroll up to 399 participants.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for side effects and other outcomes for up to approximately 60 months (5 years).

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06120283

BGB-43395 Alone or as Part of Combination Therapies in Participants With Breast Cancer and Other Advanced Solid Tumors

Recruiting
PHASE1Ages 18+InterventionalTreatment
BeOne Medicines
~433 participants
Updated 2026-08-28 on ClinicalTrials.gov
What's tested:BGB-43395FulvestrantLetrozoleElacestrantAnti-Diarrheal Agent

At a glance

Recruiting sites
58 of 62 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Phase 1a: Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)
Measured over Up to approximately 60 months
+3 more outcomes measured

Conditions

Advanced Solid Tumor
Advanced Breast Cancer
Metastatic Breast Cancer
Hormone-receptor-positive Breast Cancer
Hormone Receptor Positive Breast Carcinoma
Hormone Receptor Positive Malignant Neoplasm of Breast
HER2-negative Breast Cancer
Hormone Receptor Positive HER-2 Negative Breast Cancer

Explore related trials

Breast CarcinomaEndometrial CarcinomaLung Non-Small Cell CarcinomaMalignant Ovarian NeoplasmSolid NeoplasmHR LYSINE DEMETHYLASE AND NUCLEAR RECEPTOR COREPRESSOR

Where it's being run

62 sites across 31 states
Brazil11
France8
Seoul Teugbyeolsi6
New South Wales4
Malaysia4
Texas3
Victoria2
Colorado1

Study leadership

  • Study Director · STUDY_DIRECTOR · BeOne Medicines

Who to contact

Study Director
[email protected]
1.877.828.5568
Email the study team

Opens a ready-to-send draft in your own email app — review before sending.

Do you actually qualify for this trial?

Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.

Check eligibility for this trial ~2 min · HIPAA-protected · delete anytime
Eligibility criteria

Inclusion

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. 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

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.

What this trial measures

  • Phase 1a: Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)Up to approximately 60 months

    Number of participants with AEs and SAEs, including findings from physical examinations, electrocardiograms (ECGs), laboratory assessments, and that meet protocol-defined dose-limiting toxicity (DLT) criteria.

  • Phase 1a: Maximum Tolerated Dose (MTD) or Maximum Administered Dose (MAD) of BGB-43395Up to approximately 60 months

    MTD is defined as the highest dose evaluated for which estimated toxicity rate is the closest to the target toxicity rate of 28%. MAD is defined as the highest dose administered if MTD is not reached.

  • Phase 1a: Recommended Dose for Expansion (RDFE) of BGB-43395Up to approximately 60 months

    RDFE of BGB-43395 alone or in combination with fulvestrant, letrozole, or elacestrant will be determined based upon the MTD or MAD.

  • Phase 1b: Objective Response Rate (ORR)Up to approximately 60 months

    ORR is defined as the percentage of participants who have confirmed complete response (CR) or partial response (PR) assessed by the investigator using Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.