A First-in-Human Study Investigating BG-85738 Alone or in Combination With Other Antitumor Agents in Patients With Advanced or Metastatic Solid Tumors With Rat Sarcoma Virus (RAS) Mutations

NCT07746141 | Not Yet Recruiting Phase 1 FDA Drug

• 2 other identifiers: BG-85738-1012026-526560-20-00
• Study Type: interventional
• Target: 100
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study is to test if the BG-85738 is safe and if it works in patients with advanced solid tumors with RAS mutations when it is given on its own and in combination.

Conditions

RAS Mutation; Advanced Solid Tumor; Metastatic Solid Tumor

Outcome Measures

Primary Outcomes (6)

• Phase 1a (Part A and Part B): Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)

  An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporarily associated with the use of study treatment, whether considered related to study treatment or not. An SAE is any untoward medical occurrence that, at any dose, * Results in death * Is life-threatening * Requires hospitalization or prolongation of existing hospitalization * Results in disability/incapacity * Is congenital anomaly/birth defect * Is considered a significant medical AE by the investigator based on medical judgement

  From first dose to 30 days after last dose or initiation of a new anticancer therapy, whichever occurs first, up to approximately 24 months

• Phase 1a (Parts A and B): Number of Participants with Dose Limiting Toxicity (DLT)

  Up to approximately 1 month

• Phase 1a (Parts A and B): Maximum Tolerated Dose (MTD) or Maximum Administered Dose (MAD) of BG-85738 as monotherapy or in combination with other antitumor agents

  MTD is defined as the highest dose level with the target DLT closest but not exceeding 0.33. MAD is defined as the maximum administered dose and it is used when MTD is not reached.

  Up to approximately 1 month

• Phase 1a: Recommended Dose for Expansion (RDFE) of BG-85738

  Up to approximately 1 month

• Part 1b (Parts C and D): Overall Response Rate (ORR)

  ORR is defined as the percentage of participants who achieve complete response (CR) or partial response (PR). * CR: Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to \< 10 mm. * PR: A ≥ 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

  Up to approximately 24 months

• Phase 1b Dose Expansion: Recommended Phase 2 dose (RP2D) of BG-85738

  Up to approximately 24 months

Secondary Outcomes (13)

• Phase 1a (Part A and Part B): Terminal Half Life (t1/2) of BG-85738

  Up to approximately 2 months

• Phase 1a (Part A and Part B): Area Under the Plasma Concentration-Time Curve (AUC) of BG-85738

  Up to approximately 2 months

• Phase 1a (Part A and Part B): Minimum Observed Serum Concentration (Ctrough) of BG-85738

  Up to approximately 2 months

• Phase 1a (Part A and Part B): Maximum Observed Plasma Concentration (Cmax) of BG-85738

  Up to approximately 2 months

• Phase 1a (Part A and Part B): Overall Response Rate (ORR)

  Up to approximately 24 months

Study Arms (4)

Phase 1a: Part A- Monotherapy Dose escalation and safety

EXPERIMENTAL

Ascending dose levels of BG-85738 will be evaluated as monotherapy in participants with advanced or metastatic solid tumors with RAS mutations.

Drug: BG-85738

Phase 1a: Part B - Combination therapy Dose escalation

EXPERIMENTAL

Sequential dose levels of BG-85738, selected based on Part A data, will be evaluated in combination with tislelizumab or in combination with cetuximab.

Drug: BG-85738; Drug: Tislelizumab; Drug: Cetuximab

Phase 1b: Part C- Monotherapy dose expansion

EXPERIMENTAL

Participants with selected tumor types will receive BG-85738 monotherapy at the RDFE(s) identified in Phase 1a Part A.

Drug: BG-85738

Phase 1b: Part D - Combination therapy dose expansion

EXPERIMENTAL

Participants with select tumor types will receive BG-85738 in combination with tislelizumab or in combination with cetuximab at the RDFE(s) identified in Phase 1a Part B

Drug: BG-85738; Drug: Tislelizumab; Drug: Cetuximab

Interventions

BG-85738 DRUG

Administered orally

Phase 1a: Part A- Monotherapy Dose escalation and safety; Phase 1a: Part B - Combination therapy Dose escalation; Phase 1b: Part C- Monotherapy dose expansion; Phase 1b: Part D - Combination therapy dose expansion

Tislelizumab DRUG

Administered intravenously

Phase 1a: Part B - Combination therapy Dose escalation; Phase 1b: Part D - Combination therapy dose expansion

Cetuximab DRUG

Administered intravenously

Phase 1a: Part B - Combination therapy Dose escalation; Phase 1b: Part D - Combination therapy dose expansion

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participants are eligible to be included in the study only if they meet all the following criteria:
• Participants must sign the informed consent form and be capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
• Participants must be ≥ 18 years of age (or the legal age of consent in the jurisdiction in which the study is taking place, whichever is older), at the time of signing the ICF.
• Participants with histologically or cytologically confirmed advanced, metastatic, and unresectable solid tumors and meet study part and cohort-specific criteria
• Participants must have evidence of a RAS mutation defined as a nonsynonymous mutation in Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS), or Harvey rat sarcoma viral oncogene homolog (HRAS) at codons 12, 13, or 61 (G12, G13, or Q61), based on testing of either tumor tissue or liquid biopsy (blood or plasma) as determined by the local laboratory

You may not qualify if:

• Participants are excluded from the study if they meet any of the following criteria:
• Participants who have prior RAS-targeted therapy, including, but not limited to, KRAS mutation-specific inhibitors (with the exception of participants with NSCLC and colorectal cancer who received a G12C inhibitor), pan-KRAS inhibitors, and pan-RAS inhibitors.
• Participants who have a history of severe allergic reactions or hypersensitivity to the active ingredient and excipients of study treatment.
• Participants who are unable to comply with the requirements of the protocol.
• Participants with active leptomeningeal disease or uncontrolled, untreated brain metastases
• Participants with any malignancy ≤ 3 years before the first dose of study treatment except for the specific cancer under investigation in this study and any locally recurring cancer that has been treated curatively (e.g., resected basal or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix or breast).
• Participants with active hepatitis C.
• Participants with medical history of untreated Human Immunodeficiency Virus infection.
• Note: Other protocol defined criteria may apply.

Sponsors & Collaborators

• BeOne Medicines: lead

MeSH Terms

Conditions

Neoplasm Metastasis

Interventions

tislelizumab; Cetuximab

Condition Hierarchy (Ancestors)

Neoplastic Processes; Neoplasms; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal; Antibodies; Immunoglobulins; Immunoproteins; Blood Proteins; Proteins; Amino Acids, Peptides, and Proteins; Serum Globulins; Globulins

Study Officials

• Study Director

  BeOne Medicine

  STUDY DIRECTOR

Central Study Contacts

Study Director

CONTACT

877-828-5568; clinicaltrials@beonemed.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 30, 2026
• First Posted: August 4, 2026
• Study Start (Estimated): September 4, 2026
• Primary Completion (Estimated): September 30, 2028
• Study Completion (Estimated): September 30, 2028
• Last Updated: August 4, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR
• Time Frame: See plan description
• Access Criteria: See plan description