NCT07078604 · University of Washington
A Cancer Vaccine (STEMVAC) in Combination With Chemotherapy for the Treatment of PD-L1 Negative Metastatic Triple-Negative Breast Cancer
What this study is about
This phase II trial studies how well a cancer vaccine called STEMVAC works in combination with chemotherapy in treating patients with PD-L1 negative, triple-negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic).
View original scientific description
This phase II trial studies how well a cancer vaccine called STEMVAC works in combination with chemotherapy in treating patients with PD-L1 negative, triple-negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic). STEMVAC is designed to target proteins that are expressed on breast cancer stem cells, and it is believed to work by boosting the immune system to recognize and destroy the invader tumor cells that are causing the disease. Chemotherapy drugs work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving STEMVAC in combination with chemotherapy may be an effective treatment for PD-L1 negative metastatic triple-negative breast cancer.
Interventions
BIOLOGICAL
CD105/Yb-1/SOX2/CDH3/MDM2-polyepitope Plasmid DNA Vaccine
Given ID
DRUG
Chemotherapy
Given standard of care chemotherapy
PROCEDURE
Computed Tomography
Undergo CT scans
PROCEDURE
Computed Tomography Assisted Biopsy
Undergo CT-guided biopsy
BIOLOGICAL
Sargramostim
Given ID
PROCEDURE
Ultrasound-Guided Biopsy
Undergo ultrasound-guided biopsy
PROCEDURE
Biospecimen Collection
Undergo blood sample collection
PROCEDURE
Positron Emission Tomography (PET)
Undergo PET scan
Primary outcome measures
Incidence of immunogenicity of CD105/Yb-1/SOX2/CDH3/MDM2-polyepitope plasmid deoxyribonucleic acid vaccine (STEMVAC): Incidence of patients who develop a positive immunogenic response after vaccination
Time frame: Baseline up to 7 months after STEMVAC priming dose #3
The Th1 STEMVAC antigen specific immune response will be determined by IFN-gamma ELISPOT. Magnitude of Th1 response will be defined for each antigen in STEMVAC for each patient as the value of the corrected spots per well (CSPW) (CSPW= \[(mean of spots in the antigen stimulated wells) - (mean of antigens for the no-antigen negative control wells)\] for the same time point). Patients are considered to have preexisting immune response if the mean of spots in antigen wells is greater than the mean + 2 standard deviations of no-antigen wells at baseline. Patients are considered to have generated or enhanced antigen specific immunity post-vaccine if the maximal corrected IFN-gamma response post-vaccine is greater than the mean + 2 standard deviations of the baseline level (p \< 0.05). A patient will be considered an immunogenic responder if they develop an antigen-specific immune response to at least 1 of the 5 vaccine antigens.
Incidence of adverse events
Time frame: Up to 21 or 28 days after completion of study treatment
Will be determined by chemical and clinical parameters evaluated at various time points. Toxicity grading will be evaluated according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events version 6.0 and monitoring of adverse events will be done per Food and Drug Administration and NCI guidelines. Descriptive statistics will be provided on the key demographic and clinical variables, such as mean, standard deviation, and range for continuous variables, and percent and number for categorical variables, such as toxicity grades.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patients must be at least ≥ 18 years of age
- Note: Because no dosing or adverse event (AE) data are currently available on the use of STEMVAC in patients \< 18 years of age, children and adolescents are excluded from this study, but will be eligible for future pediatric trials, if applicable
- Patients with Eastern Cooperative Oncology Group (ECOG) Performance Status Score of ≤ 2
- Histologically confirmed triple-negative breast cancer
- Tumors with estrogen receptor (ER)-low (≤ 5%) or negative and progesterone receptor (PR)-low (≤ 5%) or negative will be included
- HER2-negative or HER2-low will be defined by the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) 2023 "Human Epidermal Growth Factor Receptor 2 (HER2) Breast Testing Guideline Update" which reaffirms the 2018 "HER2 Breast Testing Guideline Focused Update"
- Tumor is negative for PD-L1 marker testing per standard of care immunohistochemistry 22C3 pharmDx assay
- Metastatic disease that is measurable based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Target lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions
- Have at least 1 site of disease confirmed by the treating oncologist that could be biopsied during treatment. This site should not be a site that is used to determine measurable disease for efficacy purposes. Lesions that will be biopsied should not be in a previously irradiated area unless progression has been demonstrated in such lesions
- Patients should not have received any prior cancer immunotherapy in the metastatic setting
- Prior Food and Drug Administration (FDA)-approved antibody drug conjugates are allowed
- Patients are appropriate candidates to receive standard of care chemotherapy as per treating oncologist's clinical judgement
- Patients who have received prior neoadjuvant or adjuvant chemotherapy are allowed
- A minimum of 14 days washout since last systemic therapy or any palliative radiotherapy is required
- Treatment with a bisphosphate or denosumab concurrently with protocol-specific therapy is allowed while on study (it is not
Exclusion criteria
- Patients must be at least 28 days post systemic steroids prior to enrollment, unless this is a steroid administered concurrently with chemotherapy or used as part of prophylaxis to prevent intravenous (IV) contrast reactions
- Must have recovered from major infections and/or surgical procedures; and in the opinion of the investigator, not have any significant active concurrent medical illnesses or condition precluding protocol treatment
- Willing to undergo up to two serial biopsies while on study
- White blood cell (WBC) ≥ 2500/mm\^3 (Within 28 days of receiving first study vaccine)
- Lymphocyte count ≥ 500/mm\^3 (Within 28 days of receiving first study vaccine)
- Absolute neutrophil count (ANC) ≥ 1000/μL (Within 28 days of receiving first study vaccine)
- Hemoglobin (Hgb) ≥ 9 g/dL (Within 28 days of receiving first study vaccine)
- Platelets ≥ 75,000/μL (Within 28 days of receiving first study vaccine)
- Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN), except patients with Gilbert's syndrome in whom total bilirubin must be \< 3.0 mg/dL (Within 28 days of receiving first study vaccine)
- Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ≤ 1.5 x institutional ULN (Within 28 days of receiving first study vaccine)
- Creatinine ≤ 1.5 x ULN mg/dL or creatinine clearance \> 60 mL/min (Within 28 days of receiving first study vaccine)
- Patients of child-bearing potential must agree to use dual methods of contraception and have a negative urine pregnancy test at screening, and male patients must use an effective barrier method of contraception if sexually active with a person of child-bearing potential. Acceptable methods of contraception are abstinence, condoms with contraceptive foam, oral, implantable or injectable contraceptives, contraceptive patch, intrauterine device, diaphragm with spermicidal gel, or a sexual partner who is surgically sterilized or post-menopausal. Effective methods of contraception must be used throughout the study until the end of treatment on study Exclusion Criteria:
- Patient has received more than one line of prior therapy in metastatic setting
- Patients with tumors that are PD-L1-positive per standard of care immunohistochemistry 22C3 pharmDx assay
- Enrollment in a concurrent interventional clinical trial. Biomarker or tissue collection or any other non-interventional clinical trial enrollment is allowed
- Patients with any of the following cardiac conditions:
- Symptomatic restrictive cardiomyopathy
- Dilated cardiomyopathy
- Unstable angina within 4 months prior to enrollment
- New York Heart Association functional class III-IV heart failure on active treatment
- Symptomatic pericardial effusion
- Patients with any autoimmune disease or comorbidities that require chronic systemic steroids or immunosuppressants. Patients with conditions requiring inhaled, intranasal or topical steroids are permitted
- Known hypersensitivity reaction to the granulocyte-macrophage colony stimulating factor (GM-CSF) adjuvant; any known contra-indication to GM-CSF
- A non-breast malignancy requiring radiation or systemic therapy within last 5 years or any B-cell malignancy (e.g., chronic lymphocytic leukemia or follicular lymphoma) under active surveillance
- Pregnant and breastfeeding individuals
- Known history of human immunodeficiency virus (HIV) infection, hepatitis B (e.g., hepatitis B virus surface antigen \[HBsAg\] reactive), or hepatitis C (e.g., hepatitis C virus \[HCV\] ribonucleic acid \[RNA\] \[qualitative\] is detected)
- Major surgery within the 4 weeks prior to initiation of study vaccine
- Must be 14 days between a non-study vaccine, including live attenuated and non-live vaccines and any STEMVAC vaccination
- Note: The minimum of 14 days does not apply to the tetanus and diphtheria (Td) vaccine
- Any condition that may interfere with the patient's participation in the study per treating physician
Where
- Seattle, Washington
Collaborators
Kuni Foundation
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 7, 2026 · Source of record for eligibility and locations