Actively Recruiting
A Phase II Trial of the Immunogenicity of a DNA Plasmid-Based Vaccine (STEMVAC) Encoding Th1 Selective Epitopes From Five Antigens Associated With Breast Cancer Stem Cells in Patients With Metastatic Triple-Negative Breast Cancer
Led by University of Washington ยท Updated on 2026-04-07
20
Participants Needed
1
Research Sites
61 weeks
Total Duration
On this page
Sponsors
U
University of Washington
Lead Sponsor
K
Kuni Foundation
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are evaluating a phase II cancer vaccine called STEMVAC combined with chemotherapy for patients with PD-L1 negative, triple-negative breast cancer that has spread to other parts of the body. STEMVAC targets proteins found on breast cancer stem cells and aims to boost the immune system to attack tumor cells. Chemotherapy drugs are also used to stop tumor growth in various ways. This combination approach is being studied for its potential in treating this specific type of metastatic breast cancer. Patients in the study receive standard chemotherapy as chosen by their doctor. They also receive three initial doses of STEMVAC with sargramostim injected into the skin every 21 to 28 days, timed around their chemotherapy schedule. After these priming doses, patients get two booster doses at 4 and 7 months, then boosters every 6 months if the disease does not worsen or cause unacceptable side effects. During the study, patients may have biopsies guided by CT or ultrasound, as well as CT or PET scans and blood tests for research purposes. Participants are followed up 21 or 28 days after completing the treatment, then every 6 months for 3 years. Researchers monitor immune responses to the vaccine, side effects, overall response to treatment at 6 months, progression-free survival, and overall survival up to 3 years. Various scans, biopsies, and blood samples help assess these outcomes and track patient health throughout the study.
CONDITIONS
Brief Title
A Cancer Vaccine (STEMVAC) in Combination With Chemotherapy for the Treatment of PD-L1 Negative Metastatic Triple-Negative Breast Cancer
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Patients must be at least 18 years of age
- Eastern Cooperative Oncology Group (ECOG) Performance Status Score of 2 or less
- Histologically confirmed triple-negative breast cancer with ER-low (5% or less) or negative and PR-low (5% or less) or negative
- HER2-negative or HER2-low as defined by ASCO/CAP 2023 guidelines
- Tumor negative for PD-L1 marker by standard immunohistochemistry 22C3 pharmDx assay
- Measurable metastatic disease based on RECIST 1.1 criteria
- At least one disease site suitable for biopsy during treatment, not used for efficacy measurement
- No prior cancer immunotherapy in the metastatic setting
- Prior neoadjuvant or adjuvant chemotherapy allowed
- Minimum 14 days washout since last systemic therapy or palliative radiotherapy
- Patients appropriate for standard chemotherapy per oncologist's judgment
- Concurrent bisphosphate or denosumab allowed
- At least 28 days post systemic steroids prior to enrollment unless given with chemotherapy or for IV contrast prophylaxis
- Recovered from major infections or surgeries and no active concurrent illnesses precluding treatment
- Willing to undergo up to two serial biopsies during study
- Adequate blood counts and organ function within 28 days before first vaccine dose
- Use of dual contraception methods with negative pregnancy test for people of child-bearing potential and effective contraception for male patients throughout study
You will not qualify if you...
- More than one prior therapy line in metastatic setting
- Tumors positive for PD-L1 by standard immunohistochemistry 22C3 pharmDx assay
- Enrollment in another interventional clinical trial
- Cardiac conditions including symptomatic restrictive or dilated cardiomyopathy, recent unstable angina, class III-IV heart failure, or symptomatic pericardial effusion
- Autoimmune disease or need for chronic systemic steroids or immunosuppressants (inhaled or topical steroids allowed)
- Known allergy or contraindication to GM-CSF (granulocyte-macrophage colony stimulating factor)
- Non-breast malignancy requiring recent therapy or active B-cell malignancy
- Pregnancy or breastfeeding
- Known HIV, hepatitis B or C infection
- Major surgery within 4 weeks before vaccine start
- Less than 14 days between any non-study vaccine and STEMVAC vaccine (except tetanus/diphtheria vaccine)
- Any medical condition interfering with participation as judged by treating physician
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 to 2 visits depending on biopsy procedures
Duration - Approximately 7 months for priming and booster doses, with booster doses every 6 months thereafter as long as eligible
Participants receive standard chemotherapy as determined by their oncologist, along with 3 priming doses of the STEMVAC vaccine with sargramostim given intradermally every 21 to 28 days, followed by 2 booster doses at 4 and 7 months after the third priming dose. Additional booster doses are given every 6 months if there is no disease progression or unacceptable toxicity. Participants also undergo CT or PET scans, blood sample collections, and biopsies for research throughout this period.
Multiple visits every 21 to 28 days during priming doses, plus visits at 4 and 7 months for booster doses, and ongoing visits every 6 months for additional boosters
Duration - Up to 3 years after treatment completion
After completing treatment, participants are followed up at 21 or 28 days, then every 6 months for up to 3 years to monitor health and any long-term effects.
Visits at 21 or 28 days post-treatment and then every 6 months for 3 years
Trial Site Locations
Total: 1 location
1
Fred Hutch/University of Washington Cancer Consortium
Seattle, Washington, United States, 98109
Actively Recruiting
Research Team
R
Research Coordinator(s)
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
TREATMENT
Number of Arms
1
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here