Skip to main content
OpenTrials
Completed

NCT Number: NCT06253195

BGB-43395 Alone or as Part of Combination Therapies in Chinese Participants With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors

This is an open-label, multicenter, phase 1a/1b clinical study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of BGB-43395, a cyclin-dependent kinase 4 (CDK4) inhibitor, as monotherapy or in combination with fulvestrant, letrozole, or other combination partners in Chinese participants with hormone receptor positive (HR+) and human epidermal growth factor 2 negative (HER2-) breast cancer (BC) and other advanced or metastatic solid tumors.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Advanced Solid Tumor Breast Cancer Breast Diseases Breast Neoplasms HER2-negative Breast Cancer Hormone Receptor Positive Malignant Neoplasm of Breast Hormone-receptor-positive Breast Cancer Metastatic Breast Cancer Metastatic Solid Tumor Neoplasm Metastasis Neoplasms Neoplasms by Site Neoplastic Processes Pathologic Processes Pathological Conditions, Signs and Symptoms Skin Diseases Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Beijing Cancer Hospital, Beijing, Beijing Municipality, China

Loading trial locations.

About this study

Our company, previously known as BeiGene, is now officially BeOne Medicines. Because some of our older studies were sponsored under the name BeiGene, you may see both names used for this study on this website.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Phase 1a (Dose Escalation): Participants with histologically or cytologically confirmed locally advanced or metastatic solid tumors associated with CDK4 dependency, including HR+/HER2- breast cancer. Participants must have received prior standard-of-care therapies for their disease, unless the therapy is not available or not tolerated, or is determined not appropriate based on the investigator's judgment.
  • Phase 1b (Dose Expansion): Participants with selected solid tumors including locally advanced or metastatic HR+/HER2- breast cancer.
  • Female participants with metastatic HR+/HER2- breast cancer will be required to have ovarian function suppression using gonadotropin-releasing hormone (GnRH) agonists such as goserelin or be postmenopausal.
  • Male participants with HR+/HER2- breast cancer will be required to have gonadal suppression using GnRH agonists when being treated with letrozole or fulvestrant.
  • Patients must have ≥1 measurable lesion per RECIST v1.1.
  • Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1.
  • Adequate organ function without symptomatic visceral disease.

Exclusion criteria

  • Prior therapy selectively targeting CDK4 (prior CDK4/6 inhibitor therapy is permitted).
  • Known leptomeningeal disease or uncontrolled untreated brain metastasis.
  • Any malignancy ≤ 3 years before the first dose of study drug(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. Patients receiving prophylactic antibiotics (eg, for prevention of urinary tract infection, chronic obstructive pulmonary disease, or for dental extraction) are eligible. Patients who have recovered from symptomatic COVID-19 infection can be rescreened for this study.
  • Untreated chronic hepatitis B or active hepatitis C infection.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Treatment and study plan

BGB-43395

Drug

Administered orally.

Fulvestrant

Drug

Administered via intramuscular injection.

letrozole

Drug

Administered orally.

Primary outcomes

  1. Phase 1a: Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)

    Time frame: Up to approximately 30 months

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

  2. Phase 1a: Maximum Tolerated Dose (MTD) or Maximum Administered Dose (MAD) of BGB-43395

    Time frame: Up to approximately 30 months

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

  3. Phase 1a: Recommended Dose for Expansion (RDFE) of BGB-43395

    Time frame: Up to approximately 30 months

    RDFE of BGB-43395 alone or as part of combination therapies will be determined based upon the MTD or MAD.

  4. Phase 1b: Objective Response Rate (ORR)

    Time frame: Up to approximately 30 months

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

Secondary outcomes

  1. Phase 1a: ORR

    Time frame: Up to approximately 30 months

    ORR is defined as the percentage of participants who have confirmed CR or PR assessed by the investigator using RECIST v1.1.

  2. Phase 1b: Progression-Free Survival (PFS)

    Time frame: Up to approximately 30 months

    PFS is defined as the time from the date of the first dose of study drug(s) to the date of the first documentation of progressive disease assessed by the investigator using RECIST v1.1 or death, whichever occurs first.

  3. Phase 1b: Number of Participants with AEs and SAEs

    Time frame: Up to approximately 30 months

    Number of participants with AEs and SAEs including findings from physical examinations, ECGs, and laboratory assessments as needed.

  4. Phase 1a and 1b: Duration of Response (DOR)

    Time frame: Up to approximately 30 months

    DOR is defined as the time from the first determination of an objective response by the investigator using RECIST v1.1 until the first documentation of disease progression or death, whichever occurs first.

  5. Phase 1a and 1b: Time to Response (TTR)

    Time frame: Up to approximately 30 months

    TTR is defined as the time from the date of the first dose of study drugs to the date of the first determination of objective response that is confirmed by a subsequent response as assessed by the investigator using RECIST v1.1.

  6. Phase 1b: Disease Control Rate (DCR)

    Time frame: Up to approximately 30 months

    DCR is defined as the percentage of participants with best overall response of CR, PR, or stable disease assessed by the investigator using RECIST v1.1.

  7. Phase 1b: Clinical Benefit Rate (CBR)

    Time frame: Up to approximately 30 months

    CBR is defined as the percentage of participants with best overall response of confirmed CR, PR, or stable disease lasting ≥ 24 weeks.

  8. Phase 1a: Observed plasma maximum concentration (Cmax) of BGB-43395 and its metabolite

    Time frame: From Cycle 1 Day 1 up to Cycle 7 Day 1 (each cycle is 28 days)

  9. Phase 1a: Observed plasma trough concentration (Ctrough) of BGB-43395 and its metabolite

    Time frame: From Cycle 1 Day 1 up to Cycle 7 Day 1 (each cycle is 28 days)

  10. Phase 1a: Area under the concentration-time curve (AUC) of BGB-43395 and its metabolite

    Time frame: From Cycle 1 Day 1 up to Cycle 7 Day 1 (each cycle is 28 days)

  11. Phase 1a: Half-life (t1/2) of BGB-43395 and its metabolite

    Time frame: From Cycle 1 Day 1 up to Cycle 7 Day 1 (each cycle is 28 days)

  12. Phase 1b: Plasma concentrations of BGB-43395 and its metabolite

    Time frame: From Cycle 1 Day 1 up to Cycle 5 Day 1 (each cycle is 28 days)

Sponsors and collaborators

Lead sponsor

BeOne Medicines

Industry

Registry information

Official study title

A Phase 1a/1b Study Investigating the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Antitumor Activity of the CDK4 Inhibitor BGB-43395, Alone or as Part of Combination Therapies in Chinese Patients With Advanced or Metastatic HR+/HER2- Breast Cancer and Other Solid Tumors

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Feb 12, 2024
Registry last updated
Jun 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.