GLSI-100 / Greenwich LifeSci - LARVOL DELTA

FLAMINGO-01: Phase 3 Study to Evaluate the Efficacy and Safety of HER2/Neu Peptide GLSI-100 (GP2 + GM-CSF) in HER2/Neu Positive Subjects (clinicaltrials.gov) - P3 | N=2250 | Recruiting | Sponsor: Greenwich LifeSciences, Inc. | N=750 ➔ 2250 | Trial completion date: Dec 2026 ➔ Dec 2031 | Trial primary completion date: Dec 2026 ➔ Dec 2031

Enrollment change • Trial completion date • Trial primary completion date • Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Greenwich LifeSciences Announces Approval to Expand FLAMINGO-01 into the United Kingdom (GlobeNewswire) - "The Company's application to expand FLAMINGO-01 into the UK has been formally approved by UK regulators, thus adding potentially 5-10 geographically distributed UK sites to the approximately 170-180 approved sites in the US and Europe. The Company is collaborating with The Royal Marsden, a leading cancer research institute."

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences…provided the following update on the use of commercially manufactured GP2 in FLAMINGO-01 in Europe (GlobeNewswire) - "The Company previously announced that the first three commercial lots of GP2 active ingredient were manufactured in 2023 in an approved commercial facility, which could be used to prepare approximately 200,000 doses of GP2....Data on these commercial lots was submitted to the FDA, and after review, the first commercial lot of GP2 vials was approved for use in FLAMINGO-01 in the US in early 2026....The European Medicines Agency (EMA) has completed their review and will also allow use of the same commercially manufactured GP2 lot in FLAMINGO-01 in Europe. Thus, all clinical sites in the US and Europe, which have increased from 160 sites to approximately 170-180 sites, are expected to be using the same lot with shipments to European pharmacies already under way."

Trial status • HER2 Positive Breast Cancer

Preliminary injection site reaction immune response results from open-label arm of ongoing phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in patients with breast cancer with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy (Flamingo-01). (ASCO 2026) - P3 | "The patient population is defined by these key eligibility criteria: 1) HER2/neu positive and HLA, 2) Residual disease or High risk pCR (Stage III at presentation) post neo-adjuvant therapy, 3) Exclude Stage IV, and 4) Completed at least 90% of planned adjuvant trastuzumab-based therapy. Preliminary injection site reaction data comparing vaccination over time in GLSI-100 treated non-HLA-A*02 patients showed a significant increase in immune response. Future studies may explore the use of immune responses to assess correlation of DTH to ISRs, immunogenicity of GLSI-100 by specific HLA type, timing of boosters to sustain immunity, clinical site performance, and the discontinuation of treatment for non-responders. Funding: This trial is supported by Greenwich LifeSciences."

Clinical • Late-breaking abstract • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Immunology • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (ESMO-BC 2026) - P3 | "After 1 year of trastuzumab-based therapy, 6 intradermal injections of GLSI-100 or placebo will be administered over the first 6 months and 5 subsequent boosters will be administered over the next 2.5 years. Contact Information: Greenwich LifeSciences, Inc. Stafford, TX Email: [email protected] Website: greenwichlifesciences.com"

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (AACR 2026) - P3 | "Up to 250 non-HLA-A*02 subjects will be enrolled in an open-label arm.Eligibility Criteria: The patient population is defined by these key eligibility criteria: 1) HER2/neu positive and HLA-A*02, 2) Residual disease or High risk pCR (Stage III at presentation) post neo-adjuvant therapy, 3) Exclude Stage IV, and 4) Completed at least 90% of planned trastuzumab-based therapy.Trial Objectives: The trial objectives are to: 1) Determine if GP2 therapy increases IBCFS, 2) Assess the safety profile of GP2, and 3) Monitor immunologic responses to treatment and assess relationship to efficacy and safety.Study Status: The study is actively recruiting and enrolling patients in the US and Europe at up to 150 sites.Contact Information: Greenwich LifeSciences, Inc. Stafford, TX Email: [email protected] Website: greenwichlifesciences.comFunding: This trial is supported by Greenwich LifeSciences."

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Preliminary delayed-type-hypersensitivity immune response results from open-label arm of on-going Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (AACR 2026) - P3 | "The patient population is defined by these key eligibility criteria: 1) HER2/neu positive and HLA, 2) Residual disease or High risk pCR (Stage III at presentation) post neo-adjuvant therapy, 3) Exclude Stage IV, and 4) Completed at least 90% of planned trastuzumab-based therapy. All patients (n=247) were vaccinated with GLSI-100 and continue in treatment and follow-up. The increase in the incidence of DTH reactions over time found in this preliminary analysis of GLSI-100 treated non-HLA-A*02 patients shows that GLSI-100 treatment should not be limited to the HLA-A*02 genotype. Subjects treated with GLSI-100 were increasingly able to mount an immune response to GP2 as evidenced in this preliminary data. Future investigations may explore the use of immune responses to assess: correlation of DTH to ISRs, immunogenicity of GLSI-100 by specific HLA type, timing of boosters to sustain immunity, clinical site performance, and the discontinuation of treatment for..."

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Abstract Title: Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (GlobeNewswire) - "Greenwich LifeSciences provides update on upcoming AACR Meeting....This abstract and poster will continue to update principal investigators at the conference about the study design of FLAMINGO-01."

Clinical protocol • HER2 Positive Breast Cancer

Abstract Title: Preliminary delayed-type-hypersensitivity immune response results from open-label arm of on-going Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (GlobeNewswire) - "Greenwich LifeSciences provides update on upcoming AACR Meeting....This will be the first abstract and poster from FLAMINGO-01 with statistically significant immune response data, potentially with subgroup analysis by the most prevalent HLA types....Immune responses to GP2 were measured at baseline and over time using delayed-type-hypersensitivity (DTH) skin tests and other methods. The DTH skin test measures the diameter of the skin immune response to GP2 in millimeters, 48-72 hours after intradermal injection of a low concentration of GP2 without GM-CSF."

P3 data • HER2 Positive Breast Cancer

Greenwich LifeSciences Provides Update Showing Continued Reduction in Recurrence Rate in the Open Label Arm of FLAMINGO-01 (The Manila Times) - "Greenwich LifeSciences...provided a preliminary update showing a continued reduction in the recurrence rate in the fully enrolled, 250 patient, open label non-HLA-A*02 arm of FLAMINGO-01...6 Months of Additional Patient Data Since Last Update Shows Recurrence Rate...The non-HLA-A*02 arm does not have a direct placebo comparator arm...As of this data cut, the current recurrence rate of the non-HLA-A*02 patients treated with GLSI-100, following completion of the PIS over an average of 1.2 years of patient exposure, is statistically significantly smaller than a 4% annual recurrence rate over a similar time period observed in the Katherine study (0.7% versus 4% annual recurrence rate over 1.2 patient-years..."

P3 data • HER2 Breast Cancer • HER2 Positive Breast Cancer

Additional information about the non-HLA-A*02 arm follows (The Manila Times) - "Virtually all of the non-HLA-A*02 patients have completed the primary immunization series, which is the first 6 monthly vaccinations in the study; Every 6 months approximately 110 patient-years are added to the non-HLA-A*02 patient data base; Enhertu (T-DXd) treated patients can be enrolled in FLAMINGO-01. In the future, if Enhertu is approved for high risk patients in the adjuvant setting, more Enhertu treated patients could be enrolled in FLAMINGO-01 and may recur at a lower rate than if treated with Kadcyla....Analysis of the open label data from FLAMINGO-01 has been conducted in a manner that maintains the study blind."

Trial status • HER2 Breast Cancer • HER2 Positive Breast Cancer

Greenwich LifeSciences Announces Preliminary Analysis Showing 80% Recurrence Rate Reduction in the Open Label Arm of FLAMINGO-01 (Greenwich LifeSciences Press Release) - "For the first 6 months of vaccination or PIS, the theoretical maximum patient years would be 250 patients at 0.5 years each or 125 patient years. Thus 100 completed patient years represents 80% of the maximum potential patient years and within 3 to 6 months all vaccinations during this period may be completed. For the period after the PIS is completed, the theoretical maximum patient years would be 250 patients at 3.5 years of follow-up each or 875 patient years. Thus 132 completed patient years represents 15% of the maximum potential patient years and represents an average of 9 months of follow-up time after the PIS for patients who have completed the PIS."

P3 data • HER2 Positive Breast Cancer

Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (SABCS 2025) - "After 1 year of trastuzumab-based therapy, 6 intradermal injections of GLSI-100 or placebo will be administered over the first 6 months and 5 subsequent boosters will be administered over the next 2.5 years. Email: [email protected]. Website: greenwichlifesciences.com."

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Greenwich LifeSciences Announces Completion of Enrollment in the Open Label Arm of FLAMINGO-01 (The Manila Times) - "In the double-blinded arms of the Phase III trial, approximately 500 HLA-A*02 patients are currently planned to be randomized to GLSI-100 or placebo, and up to 250 patients of other HLA types (non-HLA-A*02) are planned to be treated with GLSI-100 in a third open label arm."

Enrollment status • HER2 Positive Breast Cancer

Greenwich LifeSciences Provides Global Update on FLAMINGO-01… (GlobeNewswire) - "The Company has achieved a major milestone by screening over 1,000 patients in Flamingo-01, continuing its screening rate of approximately 150 patients per quarter or the equivalent of 600 patients per year in approximately 40 US sites and 100 EU sites for a total of 140 active sites. The Company is considering a strategy to continue enrolling in both the HLA-A*02 and non-HLA-A*02 arms until interim analyses are conducted and the appropriate size of each arm can be further assessed."

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences Announces Addition of Austria to Flamingo-01 Clinical Trial (GlobeNewswire)

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences Announces Expansion of Flamingo-01 Clinical Trial to Belgium (GlobeNewswire)

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences Announces Addition of Portugal to Flamingo-01 Clinical Trial (GlobeNewswire) - "The Company's application to European regulators has been formally approved, adding Portugal as an approved country in FLAMINGO-01 in addition to Spain, France, Germany, Italy, Poland, Romania, Ireland, and the US."

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences Announces Expansion of Flamingo-01 Clinical Trial to Ireland (GlobeNewswire) - "The Company's application to European regulators has been formally approved, adding Ireland as an approved country in FLAMINGO-01 in addition to Spain, France, Germany, Italy, Poland, Romania, and the US....FLAMINGO-01 (NCT05232916) is a Phase III clinical trial designed to evaluate the safety and efficacy of GLSI-100 (GP2 + GM-CSF) in HER2 positive breast cancer..."

Trial status • HER2 Positive Breast Cancer

Greenwich LifeSciences’ GLSI-100 Granted US FDA Fast Track Designation (GlobeNewswire) - "The designation specifically states that "GLSI-100 for the treatment of patients with HLA-A*02 genotype and HER2-positive breast cancer who have completed treatment with standard of care HER2/neu targeted therapy to improve invasive breast cancer free survival meets the criteria for Fast Track designation. The Fast Track designation for GLSI-100 may lead to earlier drug approval as the Company and the FDA can communicate more frequently to expedite the Biologic License Application (BLA) filing of the clinical and manufacturing data from FLAMINGO-01."

Evidence highlight • Fast track • HER2 Positive Breast Cancer • HER-2 • HLA-A

Greenwich LifeSciences Announces Expansion of Flamingo-01 into Romania (GlobeNewswire) - "The Company's application to expand Flamingo-01 into Romania has been formally approved by European regulators, thus adding Romanian sites to the approximately 150 approved sites in Spain, France, Germany, Italy, Poland and the US."

Trial status • HER2 Positive Breast Cancer

Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy: Flamingo-01. (ASCO 2025) - P3 | "After 1 year of trastuzumab-based therapy, 6 intradermal injections of GLSI-100 or placebo will be administered over the first 6 months and 5 subsequent boosters will be administered over the next 2.5 years. Study Status: The study is actively recruiting and enrolling patients in the US and Europe at up to 150 sites. Contact Information: Greenwich LifeSciences, Inc., Stafford, TX; Email: [email protected]; Website: greenwichlifesciences.com"

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Phase III study to evaluate the efficacy and safety of GLSI-100 (GP2 + GM-CSF) in breast cancer patients with residual disease or high-risk PCR after both neo-adjuvant and postoperative adjuvant anti-HER2 therapy, Flamingo-01 (ESMO-BC 2025) - P3 | "After 1 year of trastuzumab-based therapy, 6 intradermal injections of GLSI-100 or placebo will be administered over the first 6 months and 5 subsequent boosters will be administered over the next 2.5 years. The trial objectives are to: 1) Determine if GP2 therapy increases IBCFS, 2) Assess the safety profile of GP2, and 3) Monitor immunologic responses to treatment and assess relationship to efficacy and safety. The study is actively recruiting and enrolling patients in the US and Europe at up to 150 sites."

Clinical • P3 data • Residual disease • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CSF2 • HER-2 • HLA-A

Greenwich LifeSciences Announces Positive Immune Response Data from FLAMINGO-01 Phase III Clinical Trial (GlobeNewswire) - P3 | N=750 | FLAMINGO-01 (NCT05232916) | Sponsor: Greenwich LifeSciences, Inc. | "The Company has analyzed the preliminary immune response data from FLAMINGO-01....The number of patients experiencing an immune response increased over time from baseline through the 4th to 6th month vaccinations in both HLA-A*02 and non-HLA-A*02 arms. In addition, a baseline immune response to GP2 is being observed before any treatment with GP2 in both HLA-A*02 and non-HLA-A*02 arms. This result suggests that GP2 is a natural antigen, that may have been part of an immune response in the patient during prior trastuzumab or other treatments."

P3 data • HER2 Positive Breast Cancer

Greenwich LifeSciences Provides Update on Open Label Safety Data from FLAMINGO-01 (GlobeNewswire) - P3 | N=750 | FLAMINGO-01 (NCT05232916) | Sponsor: Greenwich LifeSciences, Inc. | "The FLAMINGO-01 DSMB met twice in 2024, most recently in December 2024, and recommended to continue the study as is without modification. No serious adverse events related to GLSI-100 have been reported to date in FLAMINGO-01....A preliminary review of FLAMINGO-01 safety data in both the HLA-A*02 treated and placebo arms and the third open label arm with all other HLA types, shows that GP2 immunotherapy continues to be well-tolerated and that no safety signal for GP2 has yet to be identified across all arms of the study. Like the Phase IIb clinical trial, the most frequent adverse event is injection site reaction, which is also a sign of an immune response."

DSMB • P3 data • HER2 Positive Breast Cancer