An Investigational Study of BG-75202 Alone and in Combination With Other Therapeutic Agents in Adults With Advanced Solid Tumors

BeOne Medicines

Status and phase: Not yet enrolling; Phase 1

Conditions: Breast Cancer; Advanced Solid Tumor

Treatments: Drug: Estrogen Receptor Antagonist; Drug: CDK4 Inhibitor; Drug: BG-75202; Drug: Aromatase Inhibitor

Study type: Interventional

Funder types: Industry

Identifiers

NCT07222267

2025-523553-34-00 (EU Trial (CTIS) Number)

BG-75202-101

Details and patient eligibility

About

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.

Enrollment: 86 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

---

86 participants in 5 patient groups

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

Experimental group

Description:

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

Treatment:

Drug: BG-75202

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

Experimental group

Description:

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

Treatment:

Drug: BG-75202

Drug: Estrogen Receptor Antagonist

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

Experimental group

Description:

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

Treatment:

Drug: BG-75202

Drug: Estrogen Receptor Antagonist

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

Experimental group

Description:

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

Treatment:

Drug: Aromatase Inhibitor

Drug: BG-75202

Drug: CDK4 Inhibitor

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

Experimental group

Description:

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

Treatment:

Drug: Aromatase Inhibitor

Drug: BG-75202

Drug: CDK4 Inhibitor