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Breast Cancer (Locally Advanced or Metastatic)Phase 1/2NCT07738341

GB268 Monotherapy or Combination Therapy for Locally Advanced/Metastatic Breast Cancer (Phase Ib/Ⅱ)

A Phase 1/2 study testing GB268, Nab-Paclitaxel and Datopotamab Deruxtecan (Dato-DXd) in people with Breast Cancer (Locally Advanced or Metastatic), run by Eddingpharm (Zhuhai) Co., Ltd..

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This is a Phase Ib/II, open-label, multi-cohort, multi-center study to evaluate the safety, tolerability, and preliminary anti-tumor activity of GB268, a biological product, as monotherapy or in combination with other therapies in patients with locally advanced unresectable or metastatic breast cancer. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
GB268, Nab-Paclitaxel and Datopotamab Deruxtecan (Dato-DXd)
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
270 participants
Where
No sites listed yet
Study dates
1 Aug 2026to 1 Aug 2030
Phase
Phase 1/2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age ≥ 18 years, male or female.
  • Histologically confirmed locally advanced unresectable or metastatic breast cancer (Triple-Negative Breast Cancer [TNBC] or Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative [HR+/HER2-]).
  • At least one measurable lesion per Response Evaluation Criteria in Solid Tumors version 1.1 [RECIST v1.1].
  • No prior treatment with any immune checkpoint inhibitor (e.g., anti-Programmed Death-1 [PD-1], anti-Programmed Death-Ligand 1 [PD-L1], anti-Cytotoxic T-Lymphocyte-Associated Protein 4 [CTLA-4]) or Programmed Death-1/Vascular Endothelial Growth Factor [PD-1/VEGF] bispecific antibody, except for adjuvant therapy if relapse occurred ≥12 months after discontinuation.
  • Assessed by the investigator as suitable for the assigned combination therapy.
  • Eastern Cooperative Oncology Group [ECOG] performance status 0 or 1.
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  • Life expectancy ≥ 3 months.
  • Adequate organ function (within 14 days before first dose, without transfusion or Granulocyte Colony-Stimulating Factor [G-CSF] support): Hemoglobin ≥ 9 g/dL, Absolute Neutrophil Count [ANC] ≥ 1.5×10^9/L, Platelets ≥ 100×10^9/L; Aspartate Aminotransferase [AST] and Alanine Aminotransferase [ALT] ≤ 3×Upper Limit of Normal [ULN] (≤5×ULN if liver metastases); Alkaline Phosphatase [ALP] ≤ 2.5×ULN (≤5×ULN if bone or liver metastases); Total Bilirubin ≤ 1.5×ULN (≤3×ULN for Gilbert's Syndrome); Serum Creatinine ≤ 1.5×ULN or Creatinine Clearance ≥ 50 mL/min (Cockcroft-Gault formula); Urine protein dipstick ≤ 1+ (if ≥2+, 24-hour urine protein quantification < 1 g); Coagulation function: International Normalized Ratio [INR] or activated Partial Thromboplastin Time [aPTT] ≤ 1.5×ULN (for patients not on anticoagulation therapy).
  • Provide a Formalin-Fixed Paraffin-Embedded [FFPE] tumor tissue sample for biomarker testing.
  • Effective contraception for fertile participants.

Who cannot join

  • Prior anti-cancer therapy within specified washout periods.
  • Systemic immunosuppressive therapy within 2 weeks before first dose.
  • Major surgery or significant traumatic injury within 4 weeks before first dose.
  • Unresolved toxicity from prior therapy > Grade 1 (except alopecia or Grade ≤2 hypothyroidism stable on hormone replacement).
  • Prior immune-related adverse events [irAEs] ≥ Grade 3 leading to treatment discontinuation.
  • Active Central Nervous System [CNS] metastases (except stable asymptomatic lesions).
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  • History of other malignancies within 3 years (except cured non-melanoma skin cancer or carcinoma in situ).
  • Uncontrolled pleural effusion or ascites requiring repeated drainage.
  • Clinically significant cardiovascular disease (e.g., myocardial infarction, unstable angina, stroke within 6 months; QTcF prolongation; New York Heart Association [NYHA] Class II-IV heart failure; pericarditis/myocarditis).
  • History of Interstitial Lung Disease [ILD] or non-infectious pneumonitis requiring steroids.
  • Active or history of autoimmune disease requiring systemic treatment in the past 2 years.
  • History of inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis, or chronic diarrhea).
  • History of hypertensive crisis or hypertensive encephalopathy.
  • Severe coagulation disorders or significant bleeding risk (e.g., severe vascular disease, hemoptysis, intracranial/spinal hemorrhage, tumor invading major vessels).
  • History of abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess.
  • Active infection requiring systemic anti-infective therapy within 2 weeks; severe infection within 4 weeks.
  • Uncontrolled intercurrent illness (e.g., poorly controlled hypertension or Type 2 diabetes mellitus).
  • Known active tuberculosis [TB].
  • Positive for Hepatitis B Virus [HBV] surface antigen [HBsAg] or core antibody [HBcAb] with HBV-Deoxyribonucleic Acid [DNA] > 500 IU/mL; or positive Hepatitis C Virus [HCV] antibody with HCV-Ribonucleic Acid [RNA] above the lower limit of quantification.
  • Known primary immunodeficiency or positive Human Immunodeficiency Virus [HIV] antibody.
  • History of solid organ or hematopoietic stem cell transplantation (except corneal transplant).
  • Pregnant or breastfeeding women.
  • Known hypersensitivity to GB268 or its excipients; history of severe hypersensitivity to other monoclonal antibodies.
  • Any other condition that would make the participant unsuitable for the study.
  • History of severe hypersensitivity to other drugs in the combination regimen.

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

About this study

Official title: A Open-label, Multicenter Phase Ib/Ⅱ Study to Evaluate the Safety, Tolerability, and Antitumor Activity of GB268 for Injection as Monotherapy or in Combination Regimens in Patients With Locally Advanced Unresectable or Metastatic Breast Cancer

This is a Phase Ib/II, open-label, multi-cohort, multi-center study to evaluate the safety, tolerability, and preliminary anti-tumor activity of GB268, a biological product, as monotherapy or in combination with other therapies in patients with locally advanced unresectable or metastatic breast cancer.

Read the detailed description

The Phase Ib part of the study will primarily assess the safety and tolerability of GB268 in combination therapies, including dose-limiting toxicities (DLTs). The Phase II part will primarily evaluate the preliminary anti-tumor activity of GB268 as monotherapy and in various combination regimens in corresponding breast cancer populations.

Being tested
GB268, Nab-Paclitaxel, Datopotamab Deruxtecan (Dato-DXd), Sacituzumab Tirumotecan
Keywords
GB268, Immunotherapy, PD-1, CTLA-4, VEGF
Medical subject headings
Breast Neoplasms, Neoplasm Metastasis, Diabetes Mellitus, Insulin-Dependent, 12

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • GB268Drug

    GB268 is a tri-specific antibody targeting PD-1, CTLA-4, and VEGF. It is designed to block immune checkpoints (PD-1/CTLA-4) to enhance T-cell-mediated anti-tumor immune responses and simultaneously inhibit VEGF-mediated tumor angiogenesis

  • Nab-PaclitaxelDrug

    Nab-Paclitaxel is a microtubule-stabilizing agent formulated as albumin-bound nanoparticles for IV administration.

  • Datopotamab Deruxtecan (Dato-DXd)Drug

    Datopotamab Deruxtecan is an ADC targeting Trop-2, consisting of a monoclonal antibody linked to a topoisomerase I inhibitor payload.

  • Sacituzumab TirumotecanDrug

    A Trop-2-directed Antibody-Drug Conjugate [ADC] consisting of a humanized anti-Trop-2 monoclonal antibody covalently linked to a topoisomerase I inhibitor payload.

Study groups in NCT07738341
Study groupRoleWhat they receive
Cohort A (GB268 + Sacituzumab Tirumotecan)ExperimentalGB268 (10 or 20 mg/kg Q3W intravenously [IV], dose selected by Safety Review Committee [SRC]) + Sacituzumab Tirumotecan 5 mg/kg once every 2 weeks [Q2W] IV. For participants with locally advanced/metastatic Triple-Negative Breast Cancer [TNBC] with no prior systemic therapy for advanced disease; no prior Trop-2 Antibody-Drug Conjugate [ADC].
Receives: Drug: GB268; Drug: Sacituzumab Tirumotecan
Cohort B (GB268 + Nab-Paclitaxel)ExperimentalGB268 (10 or 20 mg/kg Q3W IV) + Nab-Paclitaxel 260 mg/m² Day 1 Q3W IV. For participants with locally advanced/metastatic TNBC with no prior systemic therapy for advanced disease; prior adjuvant/neoadjuvant taxane allowed only if recurrence ≥12 months after last taxane dose.
Receives: Drug: GB268; Drug: Nab-Paclitaxel
Cohort E (GB268+ Datopotamab Deruxtecan)ExperimentalGB268 (10 or 20 mg/kg Q3W IV) + Datopotamab Deruxtecan 6 mg/kg Day 1 Q3W IV. For participants with HR+/HER2- breast cancer who have received at least 1 line of endocrine therapy, CDK4/6i, and at least 1 line of systemic chemotherapy in the advanced setting; no prior Trop-2 ADC.
Receives: Drug: GB268; Drug: Datopotamab Deruxtecan (Dato-DXd)
Cohort F (GB268 + Nab-Paclitaxel)ExperimentalGB268 (10 or 20 mg/kg Q3W IV) + Nab-Paclitaxel 260 mg/m² Day 1 Q3W IV. For participants with HR+/HER2- breast cancer with disease progression after ≥1 line of endocrine therapy and CDK4/6i, with primary or secondary endocrine resistance; prior adjuvant/neoadjuvant taxane allowed only if recurrence ≥12 months after last taxane dose.
Receives: Drug: GB268; Drug: Nab-Paclitaxel
Cohort G (GB268 monotherapy)ExperimentalGB268 monotherapy (dose not exceeding 30 mg/kg Q3W, selected by SRC) IV. For participants with HR+/HER2- breast cancer who have received prior CDK4/6i and endocrine therapy in any setting, and a TROP2 or HER2 ADC in the advanced setting.
Receives: Drug: GB268

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Dose-Limiting Toxicities [DLTs] (Phase Ib)

    Incidence of Dose-Limiting Toxicities [DLTs] during the first treatment cycle

    Measured: Within 21 days after first dose

  2. Objective Response Rate [ORR] (Phase II)

    ORR is the proportion of subjects with complete response(CR) or partial response(PR) , based on Investigator per Response Evaluation Criteria in Solid Tumors version 1.1 [RECIST v1.1]

    Measured: Up to approximately 2 years

Secondary outcomes (10)
  1. Number of participants with adverse events [AEs] (Phase Ib and Phase II)

    Safety as assessed by clinical laboratory tests, 12-lead electrocardiogram (ECG), vital signs measurements, and the incidence, nature and severity of all adverse events (AEs) and serious AEs (SAEs)

    Measured: Up to approximately 2 years

  2. Objective Response Rate [ORR] (Phase Ib)

    ORR is the proportion of subjects with complete response(CR) or partial response(PR) , based on RECIST v1.1.

    Measured: Up to approximately 2 years

  3. Duration of Response [DOR] (Phase Ib and Phase II)

    DOR assessed according to RECIST v1.1

    Measured: Up to approximately 2 years

  4. Overall Survival [OS] (Phase Ib and Phase II)

    OS defined as the time from the first dose to death from any cause

    Measured: Up to approximately 2 years

  5. Disease Control Rate [DCR] (Phase Ib and Phase II)

    DCR assessed according to RECIST v1.1

    Measured: Up to approximately 2 years

  6. Progression-Free Survival [PFS] (Phase Ib and Phase II)

    PFS assessed according to RECIST v1.1

    Measured: Up to approximately 2 years

  7. Cmax of GB268 of GB268 (Phase Ib and Phase II)

    Peak plasma concentration

    Measured: Up to approximately 2 years

  8. Tmax of GB268 (Phase Ib and Phase II)

    Time to peak drug concentration

    Measured: Up to approximately 2 years

  9. AUC of GB268 (Phase Ib and Phase II)

    Area under curve

    Measured: Up to approximately 2 years

  10. Number and percentage of participants with Anti-Drug Antibodies [ADAs] (Phase Ib and Phase II)

    Measured: Up to approximately 2 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted31 Jul 2026
  2. Study start1 Aug 2026 (estimated)
  3. Primary completion1 Aug 2029 (estimated)
  4. Study completion1 Aug 2030 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1/2
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
270 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07738341
Sponsor's protocol ID
GB268-201
Status last verified
Jul 2026
First submitted
23 Jul 2026
Last updated
31 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing GB268, Nab-Paclitaxel and Datopotamab Deruxtecan (Dato-DXd) in people with Breast Cancer (Locally Advanced or Metastatic), run by Eddingpharm (Zhuhai) Co., Ltd..

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 25 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 31 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Binghe Xu (86 10 67781331, xubinghe@medmail.com.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Dose-Limiting Toxicities [DLTs] (Phase Ib) (time frame: Within 21 days after first dose). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Jul 2026.

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