Greenwich LifeSciences (NASDAQ:GLSI) released a preliminary update from its ongoing Phase III FLAMINGO-01 clinical trial, which evaluates the efficacy of GP2, an immunotherapy designed to prevent breast cancer recurrences.
The update focuses on the fully enrolled, 250-patient open-label arm consisting of non-HLA-A*02 patients. Following the completion of the Primary Immunization Series (PIS), the observed recurrence rate in this group was less than 1% per year, specifically 0.7% over 1.2 patient-years of follow-up.
This preliminary figure represents an approximate 83% reduction in recurrence compared to the historical 4% annual rate observed in the benchmark Katherine study.
The statistical significance of this finding was highlighted by a Chi-Square p-value of less than 0.005.
While the data are based on initial site reports and remain subject to change as data cleaning and patient follow-up continue, the results provide a strong early signal for the potential of GP2 in a broader patient population.
The FLAMINGO-01 trial is designed to assess the safety and efficacy of GP2 in patients who have completed neoadjuvant therapy and surgery but remain at risk for recurrence.
The company noted that the majority of non-HLA-A*02 patients have now completed the initial six-month immunization series.
As the trial progresses, approximately 110 patient-years of data are being added every six months, which will eventually provide the statistical weight necessary for a formal regulatory submission.
GP2 is a 9-amino acid transmembrane peptide of the HER2/neu protein.
Unlike many traditional immunotherapies that are restricted to specific genetic profiles, Greenwich is testing the treatment across multiple HLA types to maximize its potential market reach.
The company continues to monitor patients in the double-blind, randomized portion of the study and expects to provide further data updates as the median follow-up time increases toward the trial's primary endpoint.