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QUILT-3.013: Study of Ad5 [E1-, E2b-]-HER2/Neu Vaccine (ETBX-021) in Subjects With Unresectable Locally Advanced or Metastatic HER2-Expressing Breast Cancer

Phase I Study of Ad5 [E1-, E2b-]-HER2/Neu Vaccine (ETBX-021) in Subjects With Unresectable Locally Advanced or Metastatic HER2-Low-Expressing (IHC 1+/2+) Breast Cancer

Status
Terminated
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02751528
Enrollment
3
Registered
2016-04-26
Start date
2017-03-04
Completion date
2018-08-16
Last updated
2025-01-13

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

Conditions

Cancer

Keywords

Breast Cancer, Breast Cancer male, Breast Neoplasms, Breast Neoplasms male, Vaccine, HER2, Metastatic, Locally Advanced, Unresectable, Solid Tumor, Phase 1, Cancer Vaccine

Brief summary

The purpose of this study is to determine whether ETBX-021 is safe and effective in the treatment of unresectable locally advanced or metastatic HER2-low-expressing breast cancer.

Detailed description

This is a Phase I trial in subjects with unresectable locally advanced or metastatic HER2-low expressing (IHC 1+ or 2+) breast cancer. The study will be conducted in two parts: the first part will involve dose escalation using a 3 + 3 design, and the second part will involve the expansion of the MTD or HTD to further evaluate safety, preliminary efficacy, and immunogenicity. In the first part, 3 to 6 subjects will be sequentially enrolled starting at dose cohort 1. Subjects will be assessed for dose-limiting toxicities (DLTs).

Interventions

BIOLOGICALETBX-021

ETBX-021 is a HER2-targeting vaccine comprising an Ad5 vector and a modified HER2 gene insert.

Sponsors

NantBioScience, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

1. Age ≥ 18 years. 2. Male or female. 3. Ability to understand and provide signed informed consent that fulfills Institutional Review Board (IRB)'s guidelines. 4. Histologically confirmed unresectable locally advanced or metastatic breast cancer that expresses HER2 (IHC 1+ or 2+), derived from the most recent metastatic biopsy sample available. 5. Tumor tissue (block or slides) and whole blood sample available for analysis. Archival tissue is permitted. 6. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 7. Concurrent hormone therapy is permitted. 8. Subjects who have received prior HER2-targeted immunotherapy (vaccine) are eligible for this trial if this treatment was discontinued at least 3 months prior to enrollment. 9. Resolution of all toxic side effects of prior chemotherapy, radiotherapy, or surgical procedures to NCI CTCAE Grade ≤ 1. 10. Subjects who are taking medications that do not have a known history of immunosuppression are eligible for this trial. 11. Adequate hematologic function at screening, as follows: * White blood count ≥ 3000/microliter. * Hemoglobin ≥ 9 g/dL (may not transfuse or use erythropoietin to achieve this level). * Platelets ≥ 75,000/microliter. * Prothrombin (PT)-international normalized ratio (INR) \< 1.5. * Partial thromboplastin time (PTT) \< 1.5 x upper limit of normal (ULN). 12. Adequate renal and hepatic function at screening, as follows: * Serum creatinine \< 2.0 mg/dL. * Bilirubin \< 1.5 mg/dL (except for Gilbert's syndrome which will allow bilirubin ≤ 2.0 mg/dL). * Alanine aminotransferase (ALT) ≤ 2.5 x ULN. * Aspartate aminotransferase (AST) ≤ 2.5 x ULN. 13. Multigated acquisition (MUGA) scan or echocardiogram with LVEF ≥ institutional LLN. Same imaging modality is to be used throughout the study. 14. Female subjects of childbearing potential and women \< 12 months since the onset of menopause must agree to use acceptable contraceptive methods for the duration of the study and for 7 months following the last injection of study medication. If employing contraception, two of the following precautions must be used: vasectomy of partner, tubal ligation, vaginal diaphragm, intrauterine device, condom and spermicidal (gel/foam/cream/vaginal suppository), or total abstinence. Male subjects must be surgically sterile or must agree to use a condom and acceptable contraceptive method with their partner. Female subjects who are post-menopausal are defined as those with an absence of menses for \> 12 consecutive months. 15. Ability to attend required study visits and return for adequate follow up, as required by this protocol.

Exclusion criteria

1. Subjects with HER2 IHC 3+ tumors, or IHC 2+ with an in situ hybridization (ISH) test result considered positive of HER2 amplification by ASCO-CAP HER2 test guidelines. 2. Subjects with ongoing HER2-directed therapy, including trastuzumab, pertuzumab, T-DM1, and lapatinib. 3. Participation in an investigational drug or device study within 30 days of screening for this study. 4. Pregnant and nursing women. 5. Subjects with ongoing palbociclib, everolimus, or other breast cancer therapy that interferes with the induction of immune responses. 6. Subjects with concurrent cytotoxic chemotherapy or radiation therapy. There must be at least 1 month between any other prior chemotherapy (or radiotherapy) and study treatment. Any prior HER2-targeted immunotherapy (vaccine) must have been discontinued at least 3 months before initiation of study treatment. Subjects must have recovered from all acute toxicities from prior treatment prior to screening for this study. 7. Active brain or central nervous system metastasis, seizures requiring anticonvulsant treatment, cerebrovascular accident (\< 6 months), or transient ischemic attack. 8. Subjects with a history of autoimmune disease (active or past), such as but not restricted to inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis, scleroderma, or multiple sclerosis. Autoimmune-related thyroid disease and vitiligo are permitted. 9. Subjects with serious intercurrent chronic or acute illness, such as cardiac or pulmonary disease, hepatic disease, or other illness considered by the Investigator as high risk for investigational drug treatment. 10. Subjects with a history of heart disease, such as congestive heart failure (class II, III, or IV defined by the New York Heart Association functional classification), history of unstable or poorly controlled angina, or history (\< 1 year) of ventricular arrhythmia. 11. Subjects with a medical or psychological impediment that would impair the ability of the subject to receive therapy per protocol or impact ability to comply with the protocol or protocol-required visits and procedures. 12. History of malignancy except for the following: adequately treated non-melanoma skin cancer, cervical carcinoma in situ, superficial bladder cancer, or other carcinoma that has been in complete remission without treatment for more than 5 years. 13. Presence of a known active acute or chronic infection, including human immunodeficiency virus (HIV, as determined by enzyme-linked immunosorbent assay \[ELISA\] and confirmed by western blot) and hepatitis B and hepatitis C virus (HBV/HCV, as determined by HBsAg and hepatitis C serology). 14. Subjects on systemic intravenous or oral steroid therapy (or other immunosuppressives, such as azathioprine or cyclosporin A) are excluded on the basis of potential immune suppression. Subjects must have had at least 6 weeks of discontinuation of any steroid therapy (except that used as premedication for chemotherapy or contrast-enhanced studies) prior to enrollment. 15. Subjects with known allergy or hypersensitivity to any component of the investigational product will be excluded. 16. Subjects with acute or chronic skin disorders that will interfere with injection into the skin of the extremities or subsequent assessment of potential skin reactions will be excluded. 17. Subjects vaccinated with a live (attenuated) vaccine (e.g., FluMist®) or a killed (inactivated)/subunit vaccine (e.g., PNEUMOVAX®, Fluzone®) within 28 days or 14 days, respectively, of the first planned dose of ETBX-021.

Design outcomes

Primary

MeasureTime frame
Number of Participants With Treatment-emergent Adverse Events, Number of Participants With Treatment Emergent Serious Adverse Events, and Number of Participants With Dose Limiting Toxicities (DLTs)Up to 12 months
Determine the Maximum Tolerated Dose (MTD) or Highest Tested Dose (HTD)Up to 11 months

Secondary

MeasureTime frameDescription
Duration of ResponseUp to 11 monthsThe duration of overall response is measured from the time measurement criteria are met for CR or PR (whichever is first recorded) until the first date that recurrence or PD is objectively documented (taking as reference for PD the smallest measurements recorded since the treatment started).
ORR (Confirmed Complete or Partial Response)Up to 11 monthsORR assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1.
Overall SurvivalUp to 2 yearsOS will be defined as the time from the date of first treatment to the date of death (any cause).
Progression Disease SurvivalUp to 2 yearsPFS was defined as the time from the date of first treatment to the date of disease progression or death (any cause) whichever occurred first.
Disease Control Rate (DCR)Up to 11 monthsConfirmed response or stable disease lasting for at least 6 months according to RECIST V1.1

Countries

United States

Participant flow

Participants by arm

ArmCount
5 x 10^10 VP
Ad5 \[E1-, E2b-\]-HER2/neu Vaccine, Suspension for Injection ETBX-021: ETBX-021 is a HER2-targeting vaccine comprising an Ad5 vector and a modified HER2 gene insert.
3
Total3

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyAdverse Event1
Overall StudyWithdrawal by Subject1

Baseline characteristics

Characteristic5 x 10^10 VP
Age, Continuous60.7 years
STANDARD_DEVIATION 3.21
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
3 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Histologically confirmed unresectable locally advanced or metastatic breast cancer that expresses HE3 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
3 Participants
Sex: Female, Male
Female
3 Participants
Sex: Female, Male
Male
0 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
1 / 3
other
Total, other adverse events
3 / 3
serious
Total, serious adverse events
1 / 3

Outcome results

Primary

Determine the Maximum Tolerated Dose (MTD) or Highest Tested Dose (HTD)

Time frame: Up to 11 months

Population: MTD / HTD not reached due to early termination of the study

ArmMeasureValue (NUMBER)
5 x 10^10 VPDetermine the Maximum Tolerated Dose (MTD) or Highest Tested Dose (HTD)NA virus particles
Primary

Number of Participants With Treatment-emergent Adverse Events, Number of Participants With Treatment Emergent Serious Adverse Events, and Number of Participants With Dose Limiting Toxicities (DLTs)

Time frame: Up to 12 months

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
5 x 10^10 VPNumber of Participants With Treatment-emergent Adverse Events, Number of Participants With Treatment Emergent Serious Adverse Events, and Number of Participants With Dose Limiting Toxicities (DLTs)TEAE3 Participants
5 x 10^10 VPNumber of Participants With Treatment-emergent Adverse Events, Number of Participants With Treatment Emergent Serious Adverse Events, and Number of Participants With Dose Limiting Toxicities (DLTs)TESAE1 Participants
5 x 10^10 VPNumber of Participants With Treatment-emergent Adverse Events, Number of Participants With Treatment Emergent Serious Adverse Events, and Number of Participants With Dose Limiting Toxicities (DLTs)DLT0 Participants
Secondary

Disease Control Rate (DCR)

Confirmed response or stable disease lasting for at least 6 months according to RECIST V1.1

Time frame: Up to 11 months

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
5 x 10^10 VPDisease Control Rate (DCR)1 Participants
Secondary

Duration of Response

The duration of overall response is measured from the time measurement criteria are met for CR or PR (whichever is first recorded) until the first date that recurrence or PD is objectively documented (taking as reference for PD the smallest measurements recorded since the treatment started).

Time frame: Up to 11 months

Population: Best overall response was Stable Disease, which did not meet the criteria for duration of response.

ArmMeasureValue (NUMBER)
5 x 10^10 VPDuration of ResponseNA Months
Secondary

ORR (Confirmed Complete or Partial Response)

ORR assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1.

Time frame: Up to 11 months

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
5 x 10^10 VPORR (Confirmed Complete or Partial Response)0 Participants
Secondary

Overall Survival

OS will be defined as the time from the date of first treatment to the date of death (any cause).

Time frame: Up to 2 years

ArmMeasureValue (MEDIAN)
5 x 10^10 VPOverall SurvivalNA Months
Secondary

Progression Disease Survival

PFS was defined as the time from the date of first treatment to the date of disease progression or death (any cause) whichever occurred first.

Time frame: Up to 2 years

ArmMeasureValue (MEDIAN)
5 x 10^10 VPProgression Disease SurvivalNA Months

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026