GP2

Background: Delayed type hypersensitivity (DTH) skin tests to GP2 were conducted in the randomized, active-controlled, single-blinded, multicenter Phase IIb trial investigating GLSI-100 (GP2+GM-CSF) administered in the adjuvant setting to node-positive and high-risk node-negative breast cancer patients with tumors expressing HER2. Baseline GP2 immune response as measured by the delayed-type hypersensitivity test may be an independent prognostic factor for recurrence. Knowledge of this GP2 immune response may identify a patient with increased risk of rapid recurrence.

Background: Injection site reactions (ISR) of booster injections in the randomized, active-controlled, single-blinded, multicenter Phase IIb trial of GLSI-100 (GP2+GM-CSF) administered in the adjuvant setting to node-positive and high-risk node-negative breast cancer patients with tumors expressing HER2 have been analyzed. Administering GLSI-100 boosters at 6 month intervals to patients produced a consistent nadir ISR approximately 20 mm lower than the maximum PIS ISR of 92.1 mm which is still larger than the maximum ISR in GM-CSF only patients of 60.5 mm. A patient’s immune response a month after booster dosing would theoretically be the peak ISR, which will be measured in future trials by measuring T-cell response and DTH one month after booster injections, further helping to evaluate booster strategies to sustain peak immunity over longer periods of time.

The authors did not submit an updated abstract. The original abstract should be considered final.

The authors did not submit an updated abstract. The original abstract should be considered final.

Background : GP2 is a biologic nine amino acid peptide of the HER2/ neu protein delivered in combination with an FDA-approved immunoadjuvant Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF, Sargramostim, Leukine) that stimulates an immune response targeting HER2/neu expressing cancers. This sample size provides 80% power if the annual rate of events in placebo-treated patients is 2.4% or greater. Eligibility Criteria : The patient population is defined by these key eligibility criteria: HER2/neu positive and HLA-A*02 Residual disease or High risk pCR (Stage III at presentation) post appropriate neo-adjuvant therapy Exclude Stage IV Completed at least 75% of planned trastuzumab-based therapy Trial Objectives : To determine if GP2 therapy increases invasive disease-free survival (IDFS) To assess the safety profile of GP2 To monitor immunologic responses to treatment and assess relationship to efficacy and safety Contact information : Website: greenwichlifesciences.com Funding : This trial is supported by Greenwich LifeSciences.

Background: GP2 is a biologic nine amino acid peptide of the HER2/neu protein delivered in combination with an FDA-approved immunoadjuvant Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF, sargramostim, leukine) that stimulates an immune response targeting HER2/neu expressing cancers . To monitor for any unexpected adverse events and toxicities related to GP2 therapy . Accrual: The target enrollment is up to approximately 500 patients.

Clinical Trial Registry Number: NCT00524277 Funding: Greenwich LifeSciences . The study confirms the finding from the Phase I trial evaluating GP2+GM-CSF that the vaccine is safe and well-tolerated . The majority of patients experienced only mild local and systemic toxicities . Importantly, toxicities in the GP2+GM-CSF group were comparable to those seen in the GM-CSF only group, suggesting the toxicities are attributable to GM-CSF.

Background: GP2 is a biologic nine amino acid peptide of the HER2/neu protein delivered in combination with an FDA-approved immunoadjuvant Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF, Sargramostim, Leukine) that stimulates an immune response targeting HER2/neu expressing cancers. The participant duration of the trial will be 3 years treatment plus 2 years follow-up for a total of 5 years following the first year treatment with trastuzumab-based therapy or approved biosimilar. An interim analysis is planned and patients will be stratified based on prior and current treatments, among other factors.Eligibility Criteria: The majority of breast cancer patients will be HER2/neu positive and HLA 2+, disease-free, conventionally treated node-positive, post breast tumor removal surgery and following the first year treatment with trastuzumab-based therapy.Trial Objectives:To determine if GP2 therapy reduces recurrence in HER2/neu positive breast cancer patients.To monitor the in vitro and in vivo immunologic responses to GP2 therapy and correlate these responses with the clinical outcomes.To monitor for any unexpected adverse events and toxicities related to GP2 therapy.Accrual: The target enrollment is up to approximately 500 patients.Contact information: snehal.patel@greenwichlifesciences.com

Immunological data comparing peak immunity to baseline and GP2 treated patients to placebo showed that GP2 treated patients, independent of HER2 status, experienced a significant increase in their immune response while those receiving GM-CSF only did not. Future studies may explore the use of immune responses to assess: immunogenicity of GP2 by HLA type, timing of boosters to sustain immunity, clinical site performance, and the discontinuation of treatment for non-responders.

A pivotal Phase III trial is being initiated to treat HER2 3+ patients in the neoadjuvant setting. GP2 also may be effective when used in parallel to trastuzumab based therapeutics or in combination with trastuzumab based therapeutics in HER2 1-2+ or other HER2 expressing cancers.