Recruiting

Phase 3

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

Sponsor:

Greenwich LifeSciences, Inc.

Code:

NCT05232916

Conditions

Breast Cancer

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Placebo

GLSI-100

Study Details

Brief summary:

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.

Conditions

Breast Cancer

Study ID

NCT05232916

Start date

Dec 16, 2022

Status verified date

Aug, 2026

Completion date

Dec, 2031

Anticipated

Primary completion date

Dec, 2031

Anticipated

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

Histologically confirmed diagnosis of HER2/neu positive primary breast cancer for all tumors biopsied at diagnosis (multifocal, multicentric, or synchronous contralateral disease)
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
Subject must both reside in and have been treated for their cancer in the country in which the clinical site is located.

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.

Study Design

Enrollment

2250 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: 0.9% Normal Saline

0.9% normal saline in subjects administered intradermally every month for first 6 months then every 6 months for next 2.5 years (11 intradermal injections over 3 years)

experimental: GLSI-100

GLSI-100 immunotherapy in subjects administered intradermally every month for first 6 months then every 6 months for next 2.5 years (11 intradermal injections over 3 years)

experimental: GLSI-100, Open-label

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)

Interventions

Placebo

0.9% Normal Saline

GLSI-100

500 mcg/mL GP2 and 125 mcg/mL GM-CSF

Primary outcome measure

Invasive Breast Cancer-free Survival (IBCFS) [ Time Frame: Median 4 years of follow-up (interim analyses planned) ]

Central Contacts and Locations

Central contacts

Jaye L Thompson, Ph.D.

(832) 791-2542 Jaye.Thompson@GreenwichLifeSciences.com

Locations

City of Hope - Cancer Center Phoenix

Recruiting

Goodyear, Arizona, United States, 85338

Contacts

Jenny Sanchez

jesanchez@coh.org

Felicia Lewis

flewis@coh.org

Principal Investigator:

Hope Rugo, MD

Tucson Medical Center HealthCare

Recruiting

Tucson, Arizona, United States, 85704

Contacts

Stacey Kimbell, R.N.

stacey.kimbell@tmcaz.com

Principal Investigator:

Aisha Ahmed, MD

City of Hope - Duarte Cancer Center

Recruiting

Duarte, California, United States, 91010

Contacts

Jenny Sanchez

jesanchez@coh.org

Felicia Lewis

flewis@coh.org

Principal Investigator:

Hope Rugo, MD

Providence St. Jude Medical Center - Virginia K. Crosson Cancer Center

Recruiting

Fullerton, California, United States, 92835

Contacts

Rebeca Sanchez

714 446-5177 rebeca.sanchez2@providence.org

Linda Gozar

linda.gozar@stjoe.org

Principal Investigator:

Monica E Lee, MD

City of Hope - Orange County Lennar Foundation Cancer Center

Recruiting

Irvine, California, United States, 92618

Contacts

Jenny Sanchez

jesanchez@coh.org

Felicia Lewis

flewis@coh.org

Principal Investigator:

Hope Rugo, MD

University of California San Diego - Moores Cancer Center

Recruiting

La Jolla, California, United States, 92093

Contacts

Sauntee Braddock

858-534-8248 sbraddock@health.ucsd.edu

Principal Investigator:

Rebecca Shatsky, MD

Stanford Medicine Cancer Center - Stanford Women's Cancer Center

Recruiting

Palo Alto, California, United States, 74304

Contacts

Michelle Narayan Brauer

650-721-4076 narayanm@stanford.edu

Principal Investigator:

Fauzia Riaz, MD

University of California San Francisco - Helen Diller Family Comprehensive Cancer Center

Recruiting

San Francisco, California, United States, 94158

Contacts

Amy Deluca

415-353-7288 amy.deluca@ucsf.edu

Principal Investigator:

Laura Huppert, MD

University of California Los Angeles - Hematology / Oncology Parkside

Recruiting

Santa Monica, California, United States, 90404

Contacts

Monica Rocha

mprocha@mednet.UCLA.edu

Principal Investigator:

Aashni Master, DO

PIH Health Hospital - Whittier Hospital

Recruiting

Whittier, California, United States, 90602

Contacts

Kristine Bradbury

kristine.bradbury@pihhealth.org

Principal Investigator:

Lisa Wang, MD

Rocky Mountain Cancer Centers

Recruiting

Denver, Colorado, United States, 80220

Contacts

Jennifer Hege

jennifer.hege@USOncology.com

Principal Investigator:

Mabel Mardones, MD

Yale Cancer Center - Smilow Cancer Hospital

Recruiting

New Haven, Connecticut, United States, 06511

Contacts

Adam Blanchard

adam.blanchard@yale.edu

Principal Investigator:

Michael DiGiovanna, MD, PhD

Johns Hopkins Medicine - Kimmel Cancer Center-Sibley Memorial Hospital

Recruiting

Washington D.C., District of Columbia, United States, 20016

Contacts

Hayden Chae, RN

202-364-7620 hchae5@jhmi.edu

Principal Investigator:

Cesar Santa-Maria, MD

University of Miami - Sylvester Comprehensive Cancer Center

Recruiting

Miami, Florida, United States, 33146

Contacts

Maria Ferrer-Guerra

mtf89@med.miami.edu

Principal Investigator:

Elisa Krill-Jackson, MD

Moffitt Cancer Center

Recruiting

Tampa, Florida, United States, 33612

Contacts

Julian Guerrero

julian.guerrero@moffitt.org

Principal Investigator:

Aixa Soyano Muller, MD

City of Hope - Cancer Center Atlanta

Recruiting

Newnan, Georgia, United States, 30265

Contacts

Jenny Sanchez

jesanchez@coh.org

Felicia Lewis

flewis@coh.org

Principal Investigator:

Hope Rugo, MD

Northwestern University - Northwestern Memorial Hospital

Recruiting

Chicago, Illinois, United States, 60611

Contacts

clinicaltrials@northwestern.edu

Principal Investigator:

William Gradishar, MD

City of Hope - Cancer Center Chicago

Recruiting

Zion, Illinois, United States, 60099

Contacts

Jenny Sanchez

jesanchez@coh.org

Felicia Lewis

flewis@coh.org

Principal Investigator:

Hope Rugo, MD

Maryland Oncology Hematology

Recruiting

Annapolis, Maryland, United States, 21401

Contacts

Gloria Seho-Ahiable

gloria.seho-ahiable@usoncology.com

Principal Investigator:

Jeanine Werner, MD

Massachusetts General Hospital Cancer Center

Recruiting

Boston, Massachusetts, United States, 02114

Contacts

MGH Cancer Center New Patient Access Team

877-394-5128

Principal Investigator:

Laura Spring, MD

Minnesota Oncology

Recruiting

Maple Grove, Minnesota, United States, 55369

Contacts

Kayla McDonald

kayla.mcdonald1@usoncology.com

Principal Investigator:

Nicole Jacobi, MD

Siteman Cancer Center - Washington University Medical Campus

Recruiting

St Louis, Missouri, United States, 63110

Contacts

Tracy Summa

314-362-0263 tracy.summa@wustl.edu

Principal Investigator:

Faisal Fa'ak, MD

Nebraska Cancer Specialists

Recruiting

Omaha, Nebraska, United States, 68114

Contacts

Heather Cordes

hcordes@nebraskacancer.com

Principal Investigator:

Mary Heurter Wells, MD

Nebraska Medicine - University of Nebraska Medical Center

Recruiting

Omaha, Nebraska, United States, 68198

Contacts

meghana.kesireddy@unmc.edu

Principal Investigator:

Meghana Kesireddy, MBBS

Comprehensive Cancer Centers of Nevada

Recruiting

Henderson, Nevada, United States, 89052

Contacts

Ann Lovelace

ann.lovelace@usoncology.com

Principal Investigator:

Stephani Christensen, MD

New York Oncology Hematology

Recruiting

Albany, New York, United States, 12065

Contacts

Josephine Faruol

josephine.faruol@nyoh.com

Principal Investigator:

Karen Tedesco, MD

New York-Presbyterian - Columbia University Irving Medical Center

Recruiting

New York, New York, United States, 10032

Contacts

cancerclinicaltrials@cumc.columbia.edu

Principal Investigator:

Julia McGuinness, MD

Stony Brook University Cancer Center

Recruiting

Stony Brook, New York, United States, 11794

Contacts

Pushpa Talanki

pushpa.talanki@stonybrookmedicine.edu

Jules Cohen

jules.cohen@stonybrookmedicine.edu

Principal Investigator:

Jules Cohen, MD

Oncology Hematology Care

Recruiting

Cincinnati, Ohio, United States, 45211

Contacts

Douglas Hart

douglas.hart@usoncology.com

Principal Investigator:

Patrick Ward, MD, PhD

Compass Oncology - Northwest Cancer Specialists

Recruiting

Tigard, Oregon, United States, 97223

Contacts

Jennifer Thompson

jennifer.thompson@usoncology.com

Principal Investigator:

Jay Andersen, MD

Redeemer Health - Holy Redeemer Hospital

Recruiting

Meadowbrook, Pennsylvania, United States, 19046

Contacts

Nadine Varney

215 544-5832 nvarney@holyredeemer.com

Principal Investigator:

Rabia Cattie, MD

Sidney Kimmel Comprehensive Cancer Center - Thomas Jefferson University Hospital

Recruiting

Philadelphia, Pennsylvania, United States, 19107

Contacts

215-600-9151 onctrialnow@jefferson.edu

Principal Investigator:

Maysa Abu-Khalaf, MD

Texas Oncology - Austin

Recruiting

Austin, Texas, United States, 78745

Contacts

Sara Manning

sara.manning@usoncology.com

Principal Investigator:

Kathryn Hudson, MD

Texas Oncology - Dallas Presbyterian Hospital

Recruiting

Dallas, Texas, United States, 75231

Contacts

Nancy Jones

nancy.jones@usoncology.com

Principal Investigator:

Cynthia Osborne, MD

Texas Oncology - Baylor Charles A. Sammons Cancer Center

Recruiting

Dallas, Texas, United States, 75246

Contacts

Christine Terraciano

christine.terraciano@usoncology.com

Principal Investigator:

Cynthia Osborne, MD

The University of Texas Southwestern Medical Center

Recruiting

Dallas, Texas, United States, 75390

Contacts

Meredith Carter

meredith.carter@utsouthwestern.edu

Principal Investigator:

Nisha Unni, MD

Baylor College of Medicine - Dan L. Duncan Comprehensive Cancer Center

Recruiting

Houston, Texas, United States, 77057

Contacts

Maria Rodriguez

maria.rodriguez3@bcm.edu

Principal Investigator:

Mothaffar Rimawi, MD

The University of Texas Health Sciences Center at San Antonio - Mays Cancer Center

Recruiting

San Antonio, Texas, United States, 78229

Contacts

Epp Goodwin

210-450-5798 goodwine@uthscsa.edu

Principal Investigator:

Virginia Kaklamani, MD

Texas Oncology - San Antonio Medical Center

Recruiting

San Antonio, Texas, United States, 78240

Contacts

Shannon Syring

shannon.syring@usoncology.com

Principal Investigator:

Emmalind Aponte, MD

Texas Oncology - Gulf Coast

Recruiting

Sugar Land, Texas, United States, 77479

Contacts

Melissa Howell

melissa.howell@usoncology.com

Principal Investigator:

Jorge Darcourt, MD

Texas Oncology - Tyler

Recruiting

Tyler, Texas, United States, 75702

Contacts

Shelly Maxfield

shelly.maxfield@usoncology.com

Principal Investigator:

Nanna Sulai, MD

University of Utah - Huntsman Cancer Institute

Recruiting

Salt Lake City, Utah, United States, 84112

Contacts

Janna Espinosa

janna.espinosa@hci.utah.edu

Principal Investigator:

Mei Wei, MD

Virginia Cancer Specialists

Recruiting

Fairfax, Virginia, United States, 22031

Contacts

Carrie Friedman

carrie.friedman@usoncology.com

Principal Investigator:

Shruti Tiwari, MD

More Information

Sponsor

Greenwich LifeSciences, Inc.

Last update posted

Aug 6, 2026

Last verified

Aug, 2026

Keywords

HER2/neu positive
Residual disease
pCR
Extended adjuvant
GP2
Immunotherapy
HLA type

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Greenwich LifeSciences, Inc. on 2026-08-06.