Abstract 122TiP
Background
GP2 is a biologic nine amino acid peptide of the HER2/neu protein delivered in combination with Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) that stimulates an immune response targeting HER2/neu expressing cancers, the combination known as GLSI-100. In a prospective, randomized, single-blinded, placebo-controlled, multicenter phase IIb study, no recurrences were observed in the HER2+ population after 5 years of follow-up, if the patient was treated with GLSI-100, survived, and was followed for more than 6 months (p = 0.0338). Immunotherapy elicited a potent response measured by skin tests and immunological assays. Of the 146 patients that have been treated with GLSI-100 over 4 clinical trials, GLSI-100 was well-tolerated and no serious adverse events observed were considered related to the immunotherapy.
Trial design
This phase III trial is a prospective, randomized, double-blinded, multi-center study. 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 participant duration of the trial will be 3 years treatment plus 1 additional year follow-up. Approximately 498 patients will be enrolled. To detect a hazard ratio of 0.3 in invasive breast cancer free survival (IBCFS), 28 events will be required. An interim analysis for superiority and futility will be conducted when at least 14 events have occurred. This sample size provides 80% power if the annual rate of events in placebo patients is 2.4% or greater. Up to 100 non-HLA-A*02 subjects will be enrolled in an open-label arm. The patient population is defined by these key eligibility criteria: 1) HER2/neu positive and HLA-A*02 and 2) Residual disease or High risk pCR (Stage III at presentation) post neo-adjuvant therapy. 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 has been initiated in the US with plans to open in Europe.
Clinical trial identification
NCT05232916.
Legal entity responsible for the study
Greenwich LifeSciences, Inc.
Funding
Greenwich LifeSciences, Inc.
Disclosure
S. Patel: Financial Interests, Personal, Ownership Interest: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Stocks/Shares: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Member of the Board of Directors: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Officer: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Full or part-time Employment: Greenwich LifeSciences, Inc. J. Thompson: Financial Interests, Personal, Ownership Interest: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Stocks/Shares: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Officer: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Full or part-time Employment: Greenwich LifeSciences, Inc. M. Patel: Financial Interests, Personal, Ownership Interest: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Stocks/Shares: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Full or part-time Employment: Greenwich LifeSciences, Inc. F.J. Daugherty: Financial Interests, Personal, Ownership Interest: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Stocks/Shares: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Member of the Board of Directors: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Officer: Greenwich LifeSciences, Inc.; Financial Interests, Personal, Full or part-time Employment: Greenwich LifeSciences, Inc. M. Rimawi: Other, Personal, Speaker’s Bureau: Daiichi Sankyo, Genentech, Macrogenics; Other, Personal, Other, Contracted Research: F. Hoffmann-La Roche Ltd., Pfizer; Other, Personal, Speaker’s Bureau, Greenwich LifeSciences: Seattle Genetics; Other, Personal, Principal Investigator: Greenwich LifeSciences, Inc.