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Her2-BATS and Pembrolizumab in Metastatic Breast Cancer

A Phase I/II Study of Anti-CD3 x Anti-HER2/Neu (Her2Bi) Armed Activated T Cells (ATC) and Pembrolizumab Combination Therapy in Women With Metastatic Breast Cancer

Status
Active, not recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03272334
Acronym
Breast-47
Enrollment
22
Registered
2017-09-05
Start date
2017-12-29
Completion date
2031-01-01
Last updated
2026-02-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Breast Cancer

Keywords

Metastatic Breast Cancer, Adoptive Cell Therapy, Armed Activated T-cells, Bispecific Antibodies, Immunotherapy

Brief summary

This proposal uses HER2Bi armed activated T-cells (HER2 BATs) to target breast cancer in combination with pembrolizumab (PBZ) in women with metastatic breast cancer (MBC). Phase I will determine a safe dose of the combination of PBZ and HER2 BATs in 3 to 18 patients. In the phase II portion, an additional 12 patients will be treated at the selected dose to further evaluate the safety and preliminary efficacy. Study treatment includes a combination of 8 infusions of BATs using a previously established schedule and one to three infusions of PBZ (200 mg per dose). PBZ will be added to 8 infusions of BATs in 3 schedules: #1) after the 8th BATs infusion; #2) after the 4th and 8th BATs infusions; and then, #3) before the 1st and after the 4th and 8th BATs infusions.

Detailed description

Once subjects are determined eligible, white blood cells (lymphocytes) are collected via leukapheresis procedure. Depending on arm/schedule, about 4-5 weeks later, study treatment will begin. For HER2 BATs, the white blood cells, specifically T cells, are then mixed with two proteins - OKT3 and IL-2 -- which activates the cells to multiply. After approximately 14 days in culture, the activated T cells are coated with OKT3 and trastuzumab/Herceptin (HER2Bi), and washed to remove excess Herceptin in order to produce bispecific antibody armed T cells (BATs). Cells are then frozen and stored until scheduled to be infused. Follow-up appointment schedule will include clinic visits 2 weeks, 1 month, 3 months, and 6 months after the last dose of Pembrolizumab.

Interventions

DRUGHER2 BATs with Pembrolizumab

8 infusions of HER2 BATs with 1-3 infusions of Pembrolizumab

Sponsors

University of Virginia
Lead SponsorOTHER
Merck Sharp & Dohme LLC
CollaboratorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Pembrolizumab administered in combination with HER2 Bispecific Antibody Armed Activated T-Cell (BATs) infusions

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Histologically confirmed breast cancer (infiltrating ductal or lobular breast carcinoma) with evidence of measurable metastatic disease. Metastatic disease must be biopsy proven. a. Since histologic type, lymphatic permeation, blood vessel invasion, and degree of anaplasia may be prognostic variables, appropriate slides of the primary lesion will be requested for future review. HER2, estrogen, and progesterone receptor positivity will be recorded. 2. Measurable lesion. Patients are required to have at least one measurable non-bone lesion ≥10 mm that has not been irradiated. a. Measurable metastatic disease documented by radiograph, CT scan, PET/CT, MRI, or physical exam is required. Each subject will be required to have at least one measurable lesion that has not been irradiated with a minimum size in at least one diameter of ≥ 10 mm for liver lesions, lung, skin, and ≥ 15 mm lymph node metastases. Biopsy of recurrent site(s) is not required. 3. Patients must have HER2 status determined by FISH or IHC. HER2 status of positive or negative are both eligible for the study. In order to be eligible for participation in this trial, the patient must also: 4. Be female ≥ 18 years of age 5. Be willing and able to provide written informed consent for the trial. 6. Have a performance status (PS) ECOG 0-1 7. Have a life expectancy ≥ 3 months 8. Be eligible for apheresis, as determined by the Stem Cell Transplant team 9. Demonstrate adequate organ function as defined below, all screening labs should be performed within 10 days prior to apheresis. Absolute lymphocyte count ≥ 500/mm3 Absolute neutrophil count (ANC) ≥1,500 /mcL Platelets ≥ 100,000 / mcL Hemoglobin ≥ 9 g/dL (or ≥5.6 mmol/L without transfusion or EPO dependency (within 7 days of assessment) BUN ≤ 1.5 X upper limit of normal (ULN) Serum creatinine OR ≤1.5 X upper limit of normal (ULN) OR Measured or calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) ≥60 mL/min for subject with creatinine levels \> 1.5 X institutional ULN Serum total bilirubin ≤ 1.5 X ULN OR AST (SGOT) and ALT (SGPT) ≤ 2.5 X ULN OR ≤ 5 X ULN for subjects with liver metastases Albumin \>2.5 mg/dL International Normalized Ratio (INR) or Prothrombin Time (PT) ≤1.5 X ULN unless subject is receiving anticoagulant therapy Activated Partial Thromboplastin Time (aPTT) as long as PT or PTT is within therapeutic range of intended use of anticoagulants 10. Female patients of childbearing potential should have a negative urine or serum pregnancy test at screening. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. 11. Female patients of childbearing potential must be willing to use an adequate method of contraception as outlined in Section 4.5.2, for the course of the study through 120 days after the last dose of study medication. 12. Patients must have had two or more lines of prior therapy (chemo or hormonal) in the metastatic setting

Exclusion criteria

The patient must be excluded from participating in the trial if the subject: 1. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to leukapheresis. 2. Has a known history of active TB (Bacillus Tuberculosis) 3. Hypersensitivity to PBZ or any of its excipients. 4. Lack of recovery (i.e., ≤ Grade 1 or baseline prior to last line of cancer therapy) from non-laboratory adverse events except ≤ Grade 2 neuropathy 5. Has history of another malignancy within the past 5 years. Exceptions include basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer. 6. Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Subjects with previously treated brain metastases may participate provided they are stable (without evidence of progression by imaging for at least four weeks prior to the first dose of trial treatment and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroids for at least 7 days prior to leukapheresis. This exception does not include carcinomatous meningitis which is excluded regardless of clinical stability. 7. Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. 8. Has known history of, or any evidence of active, non-infectious pneumonitis. 9. Has an active infection requiring systemic therapy. 10. Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator. 11. Is pregnant or breastfeeding, or expecting to conceive children within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment. 12. Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent. 13. Has Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies) or known history of Hepatitis B (e.g., HBsAg reactive) or Hepatitis C antibody is detected. Note: Patients may be eligible if HCV antibody is detected as long as HCV viral load is undetectable following an FDA approved treatment regimen 14. Has received a live vaccine within 30 days of apheresis. Note: Seasonal influenza vaccines for injection are generally inactivated flu vaccines and are allowed; however intranasal influenza vaccines (e.g., Flu-Mist®) are live attenuated vaccines, and are not allowed. 15. Has a history of significant cardiac disease, including: * History of a recent myocardial infarction (within one year), a past myocardial infarction (more than one year ago) along with current coronary symptoms requiring medications and/or evidence of depressed left ventricular function (LVEF \< 45% by MUGA or ECHO). * Current history of angina/coronary symptoms requiring medications and/or evidence of depressed left ventricular function (LVEF \< 45% by MUGA or ECHO) * Clinical evidence of congestive heart failure requiring medical management (irrespective of ECHO results). 16. Pt may be excluded if, in the opinion of the PI and investigator team, the pt is not capable of being compliant.

Design outcomes

Primary

MeasureTime frameDescription
Dose Limiting Toxicities (Escalation and Expansion Cohorts)From start of study treatment until 3 weeks after last dose of study treatment, assessed over about 10 weeks.Maximum tolerated dose will be based on number of dose limiting toxicities in each schedule/arm

Secondary

MeasureTime frameDescription
Dose Limiting Toxicities on the Selected Arm in the Expansion CohortFrom start of study treatment until 3 weeks after last dose of study treatment, assessed over about 10 weeks.Dose Limiting toxicities on the arm selected based on the dose/schedule selection part of the study.
Objective Response RateImaging will be done prior to study treatment, 1 month, 3 months and 6 months after completion of study treatment (about 8.5 months after starting study treatment). Imaging will then be performed according to standard of care.The percentage of subjects with a response of complete response (CR) or partial response (PR) per immune related response criteria (irRC)
Overall SurvivalEvery 3 months following last study visit until deathTime from enrollment until death from any cause
Progression-Free SurvivalChecked from enrollment through first progression, about every 3 months, through death or end of studyTime from enrollment to time of first progression after enrollment (days)
Immune Response to Treatment in BloodBlood will be collected about 5 weeks before any treatment, just before first HER2 BATs infusion, before HER2 BATs #5, before HER2 BATs #8, and 2 weeks, 1 month, 3 months, and 6 months after last PembrolizumabSequential monitoring of phenotype, IFN-γ EliSpots, anti-breast cancer cytotoxicity of peripheral blood mononuclear cells (PBMC) directed at breast cancer cell lines, Th1/Th2 serum cytokine patterns, and anti-breast cancer antibodies in the serum during the "vaccinate and consolidate" process
Disease Control RateImaging will be done prior to study treatment, 1 month, 3 months and 6 months after completion of study treatment. Imaging will then be performed according to standard of care.The percentage of subjects who achieve complete response, partial response and stable disease following treatment.
Duration of ResponseImaging will be done prior to study treatment, 1 month, 3 months and 6 months after completion of study treatment. Imaging will then be performed according to standard of care.The time from documentation of tumor response to disease progression.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORPatrick Dillon, MD

University of Virginia

Participant flow

Pre-assignment details

22 participants were enrolled, but only 17 initiated cellular infusions (study treatment).

Baseline characteristics

Characteristic
Age, Customized
Median (SD)
54.6 years
STANDARD_DEVIATION 13.7
ECOG Performance status1.2 units on a scale
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
7 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
0 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
21 Participants
Region of Enrollment
United States
8 participants
Sex: Female, Male
Female
22 Participants
Sex: Female, Male
Male
0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
deaths
Total, all-cause mortality
3 / 37 / 73 / 34 / 4
other
Total, other adverse events
3 / 37 / 73 / 34 / 4
serious
Total, serious adverse events
1 / 31 / 70 / 32 / 4

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 28, 2026