Recruiting
Phase 1

BG-75202

Sponsor:

BeOne Medicines

Code:

NCT07222267

Conditions

Breast Cancer

Advanced Solid Tumor

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

BG-75202

CDK4 Inhibitor

Estrogen Receptor Antagonist

Aromatase Inhibitor

Study Details

Brief summary:

The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and preliminary antitumor activity of BG-75202 (KAT6A/B inhibitor) alone and in combination with other therapies in participants with breast cancer and other advanced solid tumors.

Conditions

Breast Cancer

Advanced Solid Tumor

Study ID

NCT07222267

Start date

Dec 11, 2025

Status verified date

Aug, 2026

Completion date

Jan 13, 2037

Anticipated

Primary completion date

Sep 30, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Part 1A: Participants with histologically or cytologically confirmed advanced, metastatic breast cancer and other solid tumors who have exhausted, are intolerant of all available standard of care therapies, and/or without available standard of care therapies.
  • Part 1B and Part 2A: Participants with advanced breast cancer with 1 to 3 prior lines of systemic therapy in the metastatic setting. Prior lines in the advanced/ metastatic setting may not exceed 2 lines of chemotherapy (inclusive of antibody-drug conjugate with cytotoxic payload).
  • Parts 2B and 2C: Participants with advanced breast cancer enrolled in regions where cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are not approved and/or not available as the first-line treatment and who are CDK4/6 inhibitor treatment naïve and did not receive any previous systemic treatment for advanced disease.
  • Participants with breast cancer must have histologically or cytologically confirmed advanced breast cancer at the time of most recent testing, based on American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.
  • Female participants with metastatic breast cancer must be postmenopausal or receiving ovarian function suppression treatment.
  • Measurable disease as assessed by Response Evaluation Criteria in Solid Tumors (RECIST) v 1.1.
  • Stable Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
  • Adequate organ function.

Exclusion Criteria:

  • Prior exposure to KAT6A/B or KAT7 inhibitors/degraders.
  • Patients with active leptomeningeal disease or uncontrolled, untreated brain metastasis.
  • Participants with any malignancy ≤ 3 years before screening for the study except for the specific cancer under investigation in this study and any locally recurring cancer that has been treated curatively which in the opinion of the investigator is unlikely to require intervention during the study.

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

Study Design

Enrollment

86 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Part 1A: Dose Escalation and Safety Expansion, BG-75202 Monotherapy

Sequential cohorts of increasing dose levels of BG-75202 will be evaluated as monotherapy.

experimental: Part 1B: Dose Escalation and Safety Expansion, BG-75202 + Estrogen Receptor Antagonist

Sequential cohorts of increasing dose levels of BG-75202 will be evaluated in combination with an estrogen receptor antagonist.

experimental: Part 2A: Dose Optimization, BG-75202 + Estrogen Receptor Antagonist

Participants will receive BG-75202 in combination with an estrogen receptor antagonist.

experimental: Part 2B: Safety Run-In, BG-75202 + CDK4 inhibitor + Aromatase Inhibitor

Participants will receive BG-75202 in combination with a cyclin-dependent kinase 4 (CDK4) inhibitor and an aromatase inhibitor.

experimental: Part 2C: Dose Expansion, BG-75202 + CDK4 inhibitor + Aromatase Inhibitor

Participants will receive BG-75202 in combination with a CDK4 inhibitor and an aromatase inhibitor.

Interventions

BG-75202

Administered orally.

CDK4 Inhibitor

Administered orally.

Estrogen Receptor Antagonist

Administered by intramuscular injection.

Aromatase Inhibitor

Administered orally.

Primary outcome measure

  • Part 1: Number of Participants with Adverse Events (AEs) [ Time Frame: From first dose to 30 days after last dose or initiation of a new anticancer therapy, whichever occurs first, up to approximately 12 months ]
  • Part 1: Recommended Dose for Expansion (RDFE) [ Time Frame: Estimated approximately 1 year ]
  • Part 2: Overall Response Rate (ORR) [ Time Frame: Up to approximately 2 years ]

Central Contacts and Locations

Central contacts

Study Director

877-828-5568clinicaltrials@beonemed.com

Locations

University of Alabama At Birmingham Hospital

Recruiting

Birmingham, Alabama, United States, 35294-0004

Yale Cancer Center

Recruiting

New Haven, Connecticut, United States, 06510

Washington University in St Louis

Recruiting

St Louis, Missouri, United States, 63110-1010

Next Oncology Austin

Recruiting

Austin, Texas, United States, 78758

The University of Texas Md Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030-4009

Fred Hutchinson Cancer Research Center

Recruiting

Seattle, Washington, United States, 98109-4433

More Information

Sponsor

BeOne Medicines

Last update posted

Aug 14, 2026

Last verified

Aug, 2026

Keywords

  • KAT6 inhibitor

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by BeOne Medicines on 2026-08-14.