Malignant Neoplasm of BreastPhase 2NCT05159778
Phase 2 Study of Imprime PGG and Pembrolizumab in Patients With HR+/HER2- Metastatic Breast Cancer (mBCA)
A Phase 2 study testing Imprime PGG and Pembrolizumab in people with Malignant Neoplasm of Breast, run by HiberCell, Inc. at 16 sites in United States.
Trial summary
The primary objective of this Phase 2 Simon 2-Stage study is to determinate the Overall Response Rate (ORR) per RECIST v1.1 following treatment with Imprime PGG + pembrolizumab in patients with ER/PR+/ HER2(-) metastatic breast cancer who have progressed through prior hormone therapy with at least one CDK4/6… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Malignant Neoplasm of Breast
- What is being tested?
- Imprime PGG and Pembrolizumab
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 26 participants
- Where
- 16 sitesUnited States
- Study dates
- 9 Nov 2021to 12 Apr 2023
- Phase
- Phase 2
- Are there results?
- None posted in the registry
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
- The patient (or legally acceptable representative if applicable) provides written informed consent for the trial.
- Be 18 years of age on day of signing informed consent.
- Have historically confirmed histological diagnosis of metastatic ER/PR+/HER2(-) subtype breast cancer
- HR+: Positive for estrogen receptor and/or progesterone receptor staining, indicated by ≥1% immunoreactive tumor nuclei
- HER2-: Immunohistochemistry assay demonstrating no or faint staining in ≤10% of tumor cells (IHC score of 0 to 1+) or negative by dual probe in situ hybridization assay
- Have peripheral blood levels of IgG anti-β-glucan antibody (ABA) of greater than, or equal to 20 mcg/mL as determined by an ELISA test within 90 days prior to start of study treatment.
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- Must have progressed on at least one hormone therapy (AI or SERD) + CDK 4/6 inhibitor (and alpelisib if PIK3CA mutated) and up to two lines of prior chemotherapy (i.e., capecitabine, taxanes). (Patient may have progressed after any number of hormone therapies alone or combined with small molecule inhibitors, i.e., mTOR, PIK3CA, CDK 4/6, etc.)
- Have documented objective radiographic or clinical disease progression after treatment with estrogen-targeted therapies with at least one CDK4/6 inhibitor.
- Be willing to provide an archival tissue sample and undergo one on-treatment core or excisional biopsy of a tumor lesion not previously irradiated (Formalin-fixed, paraffin embedded [FFPE]tissue blocks are preferred to slides).
- Have at least one radiologically measurable lesion as per RECIST v1.1 defined as a lesion that is at least 10 mm in longest diameter imaged by CT scan or MRI and obtained by imaging within 28 days prior to registration. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.
- Note: Patients with bone only metastases (BOM) are not eligible, except if such lesions have a distinct, associated soft tissue component that is measurable as per RECIST 1.1.
- Have resolution of all previous treatment-related toxicities to Grade 1 severity or lower, except for stable sensory neuropathy (less than or equal to Grade 2) and alopecia. If the patient received major surgery or radiation therapy of > 30 Gy, must have recovered from the toxicity and/or complications from the intervention.
- Have Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
- Have life expectancy of 3 months or greater as determined by the treating physician.
- Have a negative PCR test at screening for SARS-COV-2 RNA.
- Have adequate organ function (all screening labs should be performed within 10 days prior to treatment initiation):
- Female patients of childbearing potential must have a negative urine or serum pregnancy within 72 hours prior to receiving the first dose of study medication. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.
- A female patient is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies
- Not a woman of childbearing potential (WOCBP)
- A WOCBP who agrees to follow contraceptive guidance during the treatment period and for at least 120 days after the last dose of study treatment.
- Be willing and have the ability to comply with scheduled visits (including geographical proximity), treatment plans, laboratory tests, and other study procedures.
Who cannot join
- The patient must be excluded from participating in the trial if the patient:
- Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., CTLA-4, OX 40, CD137).
- Has received prior radiotherapy within 2 weeks of start of study treatment. Patients must have recovered from all radiation-related toxicities, not require corticosteroids, and not have had radiation pneumonitis. A 1-week washout is permitted for palliative radiation (≤2 weeks of radiotherapy) to non-CNS disease.
- Has received prior systemic anti-cancer therapy including investigational agents within 4 weeks to Study Day 1 (or within 2 weeks for kinase inhibitors or other short half-life drugs), or within 5 half-lives for a prior investigational drug and two weeks from use of an investigational device.
- Note: Patients must have recovered from all AEs due to previous therapies to ≤Grade 1 or baseline. Patients with ≤Grade 2 neuropathy may be eligible. Patients with endocrine-related AEs Grade ≤2 requiring treatment or hormone replacement may be eligible.
- Note: If the patient had major surgery, the patient must have recovered adequately from the procedure and/or any complications from the surgery prior to starting study intervention.
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- Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study treatment.
- Note: Patients who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent.
- Has received a live or live-attenuated vaccine within 30 days prior to the first dose of study intervention. Note:
- Administration of killed vaccines are allowed.
- Has had an allogeneic tissue/solid organ transplant.
- Has received transfusion of blood products (including platelets or red blood cells) or administration of colony stimulating factors (including G-CSF, GM-CSF, or recombinant erythropoietin) within 4 weeks prior to Study Day 1.
- Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior the first dose of study drug.
- Has a known additional malignancy that is progressing or has required active treatment within the past 3 years.
- Note: Patients with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ (e.g., breast carcinoma, cervical cancer in situ) that have undergone potentially curative therapy are not excluded.
- Has known active CNS metastases and/or carcinomatous meningitis. Patients with previously treated brain metastases may participate provided they are radiologically stable, i.e., without evidence of progression for at least 4 weeks by repeat imaging (note that the repeat imaging should be performed during study screening), clinically stable and without requirement of steroid treatment for at least 14 days prior to first dose of study treatment.
- Has severe hypersensitivity (≥Grade 3) to pembrolizumab and/or any of its excipients.
- Had previous exposure to Imprime PGG.
- Has an active autoimmune disease that has required systemic treatment in 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) is not considered a form of systemic treatment and is allowed.
- Has a history of (non-infectious) pneumonitis / interstitial lung disease that required steroids or has current pneumonitis/ interstitial lung disease.
- Has an active infection requiring systemic therapy.
- Has known history of active tuberculosis.
- Has a known history of HIV infection. No HIV testing is required unless mandated by local health authority.
- Has a known history of Hepatitis B (defined as HBsAg reactive) or known active Hepatitis C virus (defined as HCV RNA [qualitative] is detected) infection.
- Note: No testing for Hepatitis B and Hepatitis C is required unless mandated by a local health authority.
- Has a clinically significant cardiovascular disease such as unstable angina, myocardial infarction, or acute coronary syndrome within ≤ 6 months prior to start of study treatment, symptomatic or uncontrolled arrhythmia, congestive heart failure, or any Class 3 or 4 cardiac disease as defined by the New York Heart Association Functional Classification.
- Has any other concurrent severe and/or uncontrolled medical condition that would, in the investigator's judgment, contraindicate the patient in the clinical study.
- Has a known psychiatric or substance abuse disorder that would interfere with the patient's ability to cooperate with the requirements of the study.
- A WOCBP who has a positive urine pregnancy test (within 72 hours) prior to treatment. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.
- Is breast feeding or expecting to conceive children within the projected duration of the trial, starting with the prescreening or screening visit through 120 days after the last dose of trial treatment.
- Is a first-degree relative of the investigator, study staff or study sponsor.
Trial locations and contacts
16 sites in 1 country.
16 sites in 1 country
United States16 sites
University of New Mexico Comprehensive Cancer Center
Albuquerque, New Mexico, 87131
St. Vincent - Frontier Cancer Center
Billings, Montana, 59102
University of Colorado at Denver
Denver, Colorado, 80045
The University of Texas MD Anderson Cancer Center
Houston, Texas, 77030
St. Luke's Cancer Institute
Kansas City, Missouri, 64111
Baptist Clinical Research Institute
Memphis, Tennessee, 38120
University of Miami and Clinics -Sylvester Comprehensive Cancer Center
Miami, Florida, 33136
Mt. Sinai (Miami)
Miami Beach, Florida, 33140
Louisiana State University Health Sciences Center - New Orleans
New Orleans, Louisiana, 70112
Columba University Medical Center
New York, New York, 10032
Thomas Jefferson University- Sidney Kimmel Cancer Center
Philadelphia, Pennsylvania, 19107
HealthPartners Cancer Research Center
Saint Louis Park, Minnesota, 55426
Stony Brook University
Stony Brook, New York, 11794
Moffitt Cancer Center
Tampa, Florida, 33612
The University of Arizona Cancer Center - North Campus
Tucson, Arizona, 10032
The University of Arizona Cancer Center
Tucson, Arizona, 85719
About this study
Official title: A Multicenter, Open-label, Phase 2 Study of Imprime PGG and Pembrolizumab in Patients With Metastatic Breast Cancer (mBCA) Who Have Progressed Through Prior Hormonal Therapy
The primary objective of this Phase 2 Simon 2-Stage study is to determinate the Overall Response Rate (ORR) per RECIST v1.1 following treatment with Imprime PGG + pembrolizumab in patients with ER/PR+/ HER2(-) metastatic breast cancer who have progressed through prior hormone therapy with at least one CDK4/6 inhibitor, and a maximum of 2 subsequent chemotherapy treatment. Patients will be screened for baseline anti-β glucan antibody level (ABA; measured in peripheral blood). Those patients with an ABA greater than or equal to 20 mcg/ml and meeting all other I/E criteria, will be enrolled.
The study will enroll 47 patients with 23 patients enrolled into Stage 1. If 4 or more patients in Stage 1 have an objective response after 12 weeks of treatment, the study will proceed into Stage 2. A total of 24 patients will be enrolled in Stage 2 for a total combined population of 47. Overall, objective responses must be observed in 10 patients for the study to be declared a success.
Read the detailed description
Study PGG-BCA-2121 is a multicenter, open-label, Phase 2 study of patients with metastatic breast cancer who have progressed through prior hormonal therapy with at least one CDK4/6 inhibitor, and a maximum of 2 subsequent chemotherapy treatment. All patients will be immune checkpoint inhibitor-naive.
A total of 47 mBCA patients will be enrolled to treatment with the combination of Imprime PGG 4 mg/kg with pembrolizumab 200mg. Patients will be screened and enrolled if baseline ABA level is greater than or equal to 20 mcg/mL (ABA+) and if all other inclusion/ exclusion criteria are met (ABA is measured in peripheral blood). Approximately 200 patients will be screened (allows for pre/ early screening for ABA levels).
Dosing will occur in three-week cycles. On Day 1 of each cycle, all patients will receive Imprime PGG 4 mg/kg IV over ~ 2-4 hr (based on body weight) followed by pembrolizumab 200 mg, IV over 30 min. On Day 8 and 15 of each cycle, patients will receive only Imprime PGG. Premedications (defined by the protocol) will be administered ~30 min before initiation of Imprime PGG during Cycles 1-3 (thereafter at the physician's discretion). Patients will dose to confirmed progression, safety event, or other administrative reason requiring discontinuation; all patients are allowed to dose up to 35 cycles.
For all patients, a baseline CT/MRI will be conducted. The first scan to assess response will be conducted 12 wks post-initiation of study treatment (pre-Cycle 5) and then q12wks thereafter until confirmed progression or discontinuation. At any time, if a patient's response is progressive disease (PD), the patient will dose for an additional 4-8 wks (physician discretion) followed by a confirmatory scan. If that scan shows progressive disease, the patient will move into overall survival monitoring. Response will be assessed by RECISTv1.1 and iRECIST will be applied by the Investigator solely for clinical management of patients as described below. All scans will be read locally and by blinded central review.
At screening, an official historical diagnostic pathology report +/- archival tissue (formalin-fixed paraffin embedded [FFPE]) will be retrieved to confirm historical diagnosis of ER/PR status. All patients will have a newly obtained core or excisional biopsy at 6 wks after initiation of study treatment. Fresh biopsies at baseline and progression or End of Treatment are strongly encouraged but not mandated. Preferably, biopsies should be non-bone and if amenable, a biopsy of a liver lesion not designated as target or non-target is preferred. Patients with bone only metastases (BOM) are not eligible, except if such lesions have a distinct, associated soft tissue component that is measurable as per RECIST 1.1.
Blood samples for safety monitoring and translational endpoints will be collected on all patients as detailed in the Schedule of Activities.
- Conditions
- Malignant Neoplasm of Breast
- Being tested
- Imprime PGG, Pembrolizumab
- Keywords
- ER/PR+/ HER2(-) metastatic breast cancer
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Imprime PGGBiological
Also called Imprime, BTH-1677
Imprime PGG is a soluble, β-1,3/1,6 glucan isolated from the cell wall of a proprietary Saccharomyces cerevisiae yeast strain. Imprime PGG acts as a Pathogen-Associated Molecular Pattern (PAMP). Imprime will be administered at a dose of 4 mg/kg IV over a 2-hour infusion time on Days 1, 8 and 15 of each 3-week treatment cycle.
PembrolizumabBiological
Also called Keytruda
Pembrolizumab is a humanized monoclonal antibody against the programmed death receptor-1 protein. Pembrolizumab will be given at a fixed dose of 200 mg IV over 30 minutes on Day 1 of each 3-week treatment cycle after the Imprime infusion.
| Study group | Role | What they receive |
|---|---|---|
| Experimental | Experimental | Not described Receives: Biological: Imprime PGG; Biological: Pembrolizumab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Overall response rate (ORR)
ORR by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Secondary outcomes (11)
Median Progression Free Survival (mPFS)
PFS by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
PFS at 6, 9, 12, 18, and 24 months
PFS at 6, 9, 12, 18, and 24 months by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Median Overall Survival (mOS)
Median Overall Survival following treatment with Imprime PGG + pembrolizumab
Measured: Within 48 months of last patient enrolled
OS rates at 6, 9, 12, 18, 24 months
OS rates at 6, 9, 12, 18, 24 months following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Disease Control Rate (DCR)
Disease Control Rate by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Duration of Response (DoR)
Duration of Response by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Profile safety of Imprime PGG in combination with pembrolizumab
Safety profile of Imprime PGG in combination with pembrolizumab following treatment with Imprime PGG + pembrolizumab
Measured: Within 24 months of last patient enrolled
Correlate changes in immune cell activation markers in tumor samples and in peripheral blood immune cells with treatment outcome
Correlate phenotypic activation of CD86 (immune cell subsets monocytes, dendritic cells) and T-cell activation (Ki-67, CD38, and HLA-DR) in tumor samples and peripheral blood immune cells with treatment outcome measured by flow cytometry and immunohistochemistry (IHC).
Measured: Within 24 months of last patient enrolled
Correlate PD-L1 status and changes in the tumor immune microenvironment with treatment outcome
Correlate PD-L1 scoring with ORR, OS, and PFS measured by IHC.
Measured: Within 24 months of last patient enrolled
Correlate levels of serum anti-β-glucan antibody (ABA) with treatment outcome
To correlate anti-β-glucan antibody (ABA) concentrations in serum with ORR, OS, and PFS measured by ELISA.
Measured: Within 24 months of last patient enrolled
Correlate treatment outcome in select metastatic breast cancer subpopulations
To correlate treatment outcome with ER/PR positivity (scored from tumor biopsies by IHC at screening and end of cycle 2), prior lines of therapy, and/or comprehensive medical history.
Measured: Within 24 months of last patient enrolled
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2021
- Study start9 Nov 2021
- Primary completion22 Mar 2023
- Study completion12 Apr 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Malignant Neoplasm of BreastStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Open label Simon 2 stage design.
- Masking
- None (open label)
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- HiberCell, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Merck Sharp & Dohme LLC
- Responsible party
- Sponsor
- Investigators
- Alison Stopeck, MD, Study chair, Stony Brook University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05159778
- Sponsor's protocol ID
- PGG-BCA2121 / MK-3475-C99
- Status last verified
- Jul 2022
- First submitted
- 10 Nov 2021
- Last updated
- 22 Jun 2023
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Jun 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Open-label, Phase 2 Study of Imprime PGG and Pembrolizumab in Patients With Metastatic Breast Cancer (mBCA) Who Have Progressed Through Prior Hormonal Therapy
- ClinicalTrials.gov ID
- NCT05159778
- Acronym / sponsor ID
- PGG-BCA2121 / MK-3475-C99
- Conditions
- Malignant Neoplasm of Breast
- Keywords
- ER/PR+/ HER2(-) metastatic breast cancer
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- HiberCell, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Merck Sharp & Dohme LLC
- Study start
- 9 Nov 2021 (actual)
- Primary completion
- 22 Mar 2023 (actual)
- Study completion
- 12 Apr 2023 (actual)
- First posted
- 16 Dec 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of this Phase 2 Simon 2-Stage study is to determinate the Overall Response Rate (ORR) per RECIST v1.1 following treatment with Imprime PGG + pembrolizumab in patients with ER/PR+/ HER2(-) metastatic breast cancer who have progressed through prior hormone therapy with at least one CDK4/6 inhibitor, and a maximum of 2 subsequent chemotherapy treatment. Patients will be screened for baseline anti-β glucan antibody level (ABA; measured in peripheral blood). Those patients with an ABA greater than or equal to 20 mcg/ml and meeting all other I/E criteria, will be enrolled.
The study will enroll 47 patients with 23 patients enrolled into Stage 1. If 4 or more patients in Stage 1 have an objective response after 12 weeks of treatment, the study will proceed into Stage 2. A total of 24 patients will be enrolled in Stage 2 for a total combined population of 47. Overall, objective responses must be observed in 10 patients for the study to be declared a success.
Detailed description
Study PGG-BCA-2121 is a multicenter, open-label, Phase 2 study of patients with metastatic breast cancer who have progressed through prior hormonal therapy with at least one CDK4/6 inhibitor, and a maximum of 2 subsequent chemotherapy treatment. All patients will be immune checkpoint inhibitor-naive.
A total of 47 mBCA patients will be enrolled to treatment with the combination of Imprime PGG 4 mg/kg with pembrolizumab 200mg. Patients will be screened and enrolled if baseline ABA level is greater than or equal to 20 mcg/mL (ABA+) and if all other inclusion/ exclusion criteria are met (ABA is measured in peripheral blood). Approximately 200 patients will be screened (allows for pre/ early screening for ABA levels).
Dosing will occur in three-week cycles. On Day 1 of each cycle, all patients will receive Imprime PGG 4 mg/kg IV over ~ 2-4 hr (based on body weight) followed by pembrolizumab 200 mg, IV over 30 min. On Day 8 and 15 of each cycle, patients will receive only Imprime PGG. Premedications (defined by the protocol) will be administered ~30 min before initiation of Imprime PGG during Cycles 1-3 (thereafter at the physician's discretion). Patients will dose to confirmed progression, safety event, or other administrative reason requiring discontinuation; all patients are allowed to dose up to 35 cycles.
For all patients, a baseline CT/MRI will be conducted. The first scan to assess response will be conducted 12 wks post-initiation of study treatment (pre-Cycle 5) and then q12wks thereafter until confirmed progression or discontinuation. At any time, if a patient's response is progressive disease (PD), the patient will dose for an additional 4-8 wks (physician discretion) followed by a confirmatory scan. If that scan shows progressive disease, the patient will move into overall survival monitoring. Response will be assessed by RECISTv1.1 and iRECIST will be applied by the Investigator solely for clinical management of patients as described below. All scans will be read locally and by blinded central review.
At screening, an official historical diagnostic pathology report +/- archival tissue (formalin-fixed paraffin embedded [FFPE]) will be retrieved to confirm historical diagnosis of ER/PR status. All patients will have a newly obtained core or excisional biopsy at 6 wks after initiation of study treatment. Fresh biopsies at baseline and progression or End of Treatment are strongly encouraged but not mandated. Preferably, biopsies should be non-bone and if amenable, a biopsy of a liver lesion not designated as target or non-target is preferred. Patients with bone only metastases (BOM) are not eligible, except if such lesions have a distinct, associated soft tissue component that is measurable as per RECIST 1.1.
Blood samples for safety monitoring and translational endpoints will be collected on all patients as detailed in the Schedule of Activities.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Open label Simon 2 stage design.
| Arm | Type | Receives |
|---|---|---|
| Experimental | Experimental | Biological: Imprime PGG, Biological: Pembrolizumab |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (21 listed)
- The patient (or legally acceptable representative if applicable) provides written informed consent for the trial.
- Be 18 years of age on day of signing informed consent.
- Have historically confirmed histological diagnosis of metastatic ER/PR+/HER2(-) subtype breast cancer
- Have peripheral blood levels of IgG anti-β-glucan antibody (ABA) of greater than, or equal to 20 mcg/mL as determined by an ELISA test within 90 days prior to start of study treatment.
- Must have progressed on at least one hormone therapy (AI or SERD) + CDK 4/6 inhibitor (and alpelisib if PIK3CA mutated) and up to two lines of prior chemotherapy (i.e., capecitabine, taxanes). (Patient may have progressed after any number of hormone therapies alone or combined with small molecule inhibitors, i.e., mTOR, PIK3CA, CDK 4/6, etc.)
Key exclusion criteria (31 listed)
- Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., CTLA-4, OX 40, CD137).
- Has received prior radiotherapy within 2 weeks of start of study treatment. Patients must have recovered from all radiation-related toxicities, not require corticosteroids, and not have had radiation pneumonitis. A 1-week washout is permitted for palliative radiation (≤2 weeks of radiotherapy) to non-CNS disease.
- Has received prior systemic anti-cancer therapy including investigational agents within 4 weeks to Study Day 1 (or within 2 weeks for kinase inhibitors or other short half-life drugs), or within 5 half-lives for a prior investigational drug and two weeks from use of an investigational device.
- Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study treatment.
- Has received a live or live-attenuated vaccine within 30 days prior to the first dose of study intervention. Note:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Imprime PGGAlso: Imprime, BTH-1677Imprime PGG is a soluble, β-1,3/1,6 glucan isolated from the cell wall of a proprietary Saccharomyces cerevisiae yeast strain. Imprime PGG acts as a Pathogen-Associated Molecular Pattern (PAMP). Imprime will be administered at a dose of 4 mg/kg IV over a 2-hour infusion time on Days 1, 8 and 15 of each 3-week treatment cycle. | Biological | Experimental |
| PembrolizumabAlso: KeytrudaPembrolizumab is a humanized monoclonal antibody against the programmed death receptor-1 protein. Pembrolizumab will be given at a fixed dose of 200 mg IV over 30 minutes on Day 1 of each 3-week treatment cycle after the Imprime infusion. | Biological | Experimental |
Primary outcome
Overall response rate (ORR)
Time frame: Within 24 months of last patient enrolled
ORR by RECIST v1.1 following treatment with Imprime PGG + pembrolizumab
11 secondary outcomes
Median Progression Free Survival (mPFS)
Time frame: Within 24 months of last patient enrolled
PFS at 6, 9, 12, 18, and 24 months
Time frame: Within 24 months of last patient enrolled
Median Overall Survival (mOS)
Time frame: Within 48 months of last patient enrolled
OS rates at 6, 9, 12, 18, 24 months
Time frame: Within 24 months of last patient enrolled
Disease Control Rate (DCR)
Time frame: Within 24 months of last patient enrolled
Duration of Response (DoR)
Time frame: Within 24 months of last patient enrolled
Profile safety of Imprime PGG in combination with pembrolizumab
Time frame: Within 24 months of last patient enrolled
Correlate changes in immune cell activation markers in tumor samples and in peripheral blood immune cells with treatment outcome
Time frame: Within 24 months of last patient enrolled
Correlate PD-L1 status and changes in the tumor immune microenvironment with treatment outcome
Time frame: Within 24 months of last patient enrolled
Correlate levels of serum anti-β-glucan antibody (ABA) with treatment outcome
Time frame: Within 24 months of last patient enrolled
Correlate treatment outcome in select metastatic breast cancer subpopulations
Time frame: Within 24 months of last patient enrolled
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jun 2023.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alison Stopeck, MD study chair
Stony Brook University
16 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Imprime PGG and Pembrolizumab in people with Malignant Neoplasm of Breast, run by HiberCell, Inc. at 16 sites in United States.
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 21 inclusion and 31 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: finished, as of the sponsor's last update on 22 Jun 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 16 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
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 phase mean?
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Overall response rate (ORR) (time frame: Within 24 months of last patient enrolled). 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 22 Jun 2023.