Phase 3 Study to Evaluate the Efficacy and Safety of HER2/Neu Peptide GLSI-100 (GP2 + GM-CSF) in HER2/Neu Positive Subjects (FLAMINGO-01)

Greenwich LifeSciences

Status and phase: Enrolling; Phase 3

Conditions: Breast Cancer

Treatments: Biological: Placebo; Biological: GLSI-100

Study type: Interventional

Funder types: Industry

Identifiers

NCT05232916

GLSI-21-01

Details and patient eligibility

About

This is a prospective, randomized, double-blinded, placebo-controlled, multi-center, Phase 3 study of GLSI-100 immunotherapy in HLA-A*02 positive and HER2/neu positive subjects who are at high risk for disease recurrence and have completed both neoadjuvant and postoperative adjuvant standard of care therapy. Treatment consists of 6 intradermal injections, Primary Immunization Series (PIS), over the first 6 months of treatment and 5 booster intradermal injections spaced 6 months apart. A third open-label arm will explore GLSI-100 immunotherapy in non-HLA-A*02 positive and HER2/neu positive subjects.

Enrollment: 598 estimated patients

Sex: All

Ages: 18 to 100 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• HLA-A*02-positive, unless being enrolled in the third non-HLA-A*02 arm
• Histologically confirmed diagnosis of HER2/neu positive primary breast cancer
• Completion of both neoadjuvant and adjuvant trastuzumab-based standard of care breast cancer therapy
• Stage I, II, or III at presentation with pathologic evidence of residual invasive carcinoma in the breast or axillary lymph nodes (residual disease) at surgery following completion of neoadjuvant therapy -OR- Stage III at presentation with pathologic complete response (pCR) at surgery following completion of neoadjuvant therapy
• The subject can begin study therapy within one year of completion of adjuvant trastuzumab-based therapy and any other standard therapies, but, study therapy can be administered concurrently with endocrine therapy.
• No clinical evidence of residual or persistent breast cancer per treating physician assessment
• ECOG 0-2
• Adequate organ function
• Negative pregnancy test or evidence of post-menopausal status
• If of childbearing potential, willing to use a form of highly effective contraception

Exclusion criteria

• Stage IV cancer or metastatic breast cancer at any time
• Inflammatory breast cancer
• Receiving other investigational agents
• Receiving chemotherapy
• Requiring long-term systemic treatment with corticosteroids or other immunosuppressive therapy
• History of immunodeficiency or active autoimmune disease
• A history of serious allergic reactions, including anaphylaxis, to human granulocyte-macrophage colony-stimulating factors such as sargramostim, yeast-derived products, or any component of the investigational product
• Other malignancies except adequately treated in situ carcinoma of the cervix or basal cell or squamous cell carcinoma of the skin
• Active infection
• Known HIV infection with a detectable viral load within 6 months of the anticipated start of treatment. Note: Subjects on effective antiretroviral therapy with an undetectable viral load within 6 months of the anticipated start of treatment are eligible for this trial.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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598 participants in 3 patient groups, including a placebo group

0.9% Normal Saline

Placebo Comparator group

Description:

0.9% normal saline in HLA-A\*02 positive and HER2/neu positive subjects administered intradermally every month for first 6 months then every 6 months for next 2.5 years (11 intradermal injections over 3 years)

Treatment:

Biological: Placebo

GLSI-100

Experimental group

Description:

GLSI-100 immunotherapy in HLA-A\*02 positive and HER2/neu positive subjects administered intradermally every month for first 6 months then every 6 months for next 2.5 years (11 intradermal injections over 3 years)

Treatment:

Biological: GLSI-100

GLSI-100, Open-label

Experimental group

Description:

Open-label arm: GLSI-100 immunotherapy in non-HLA-A\*02 positive and HER2/neu positive subjects administered intradermally every month for first 6 months then every 6 months for next 2.5 years (11 intradermal injections over 3 years)

Treatment:

Biological: GLSI-100