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

BeOne Medicines

Status and phase: Enrolling; Phase 1

Conditions: Breast Cancer; Advanced Solid Tumor

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

Study type: Interventional

Funder types: Industry

Identifiers

NCT07222267

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

BG-75202-101

2025

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.

Full description

This study will enroll participants with advanced or metastatic solid tumors, including breast cancer. Breast cancer is one of the most common cancers in women.

BG-75202 is an experimental drug that blocks proteins called KAT6A and 6B. These proteins are believed to help tumor growth in a number of cancers including certain types of breast cancer and other solid tumors. By blocking KAT6A and 6B, BG-75202 may be able to slow down or stop the growth of tumor cells.

This study consists of 2 parts, one called dose escalation and safety expansion and the other called dose optimization and dose expansion.

During the dose escalation and safety expansion part, the study doctors will test different doses of the study drug. This part of the study will evaluate BG-75202 alone (monotherapy) and combined with another drug (combination therapy).

During the dose optimization and dose expansion part, the study doctors will test the study drug in a larger number of people using the dose(s) identified from dose escalation and safety expansion. In this part of the study, BG-75202 will be taken with 1 or 2 other drugs.

The study will enroll participants with advanced or metastatic solid tumors at multiple centers worldwide.

The overall time to participate in this study may be up to approximately five years. Participants will make regular visits to the clinic for treatment, health checks, blood tests, and tumor and imaging tests.

Enrollment: 186 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, Part 2A, 2B, and SE Parts 1A and 1B (except Food Effect): 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 1 line of chemotherapy (inclusive of antibody-drug conjugate with cytotoxic payload) in the advanced/metastatic setting.
• Food Effect only in SE Parts 1A or 1B: Patients with histologically or cytologically confirmed advanced, metastatic breast cancer who have exhausted, are intolerant of all available standard-of-care therapies, and/or without available standard-of-care therapies.
• Parts 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)

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186 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: Estrogen Receptor Antagonist

Drug: BG-75202

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: Estrogen Receptor Antagonist

Drug: BG-75202

Part 2B: Safety Lead-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: CDK4 Inhibitor

Drug: Aromatase Inhibitor

Drug: BG-75202

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: CDK4 Inhibitor

Drug: Aromatase Inhibitor

Drug: BG-75202