Greenwich LifeSciences has shared important updates on the phase 3 Flamingo-01 trial, which is researching GLSI-100, a new immunotherapy for patients with a specific type of breast cancer.
GLSI-100 combines a small protein fragment (GP2) from the HER2/neu protein with a substance (GM-CSF sargramostim) that encourages the immune system to attack cancer cells expressing HER2/neu.
This treatment is being studied as an additional therapy to help prevent cancer from returning in patients with HER2/neu-positive breast cancer who have already had surgery and a year of trastuzumab-based therapy.
The trial’s safety board met twice in 2023 and advised continuing the study without any changes, noting no serious side effects from GLSI-100. The trial aims to see if this treatment can extend the time patients remain free from cancer coming back.
There were discussions at two major cancer conferences in 2023 about expanding the trial to include more patients who don’t have a specific genetic marker (HLA-A*02) than originally planned, due to new findings suggesting GP2 might work in a broader group of patients.
This expansion reflects the high interest in the study and its potential to benefit a wider patient population.
Flamingo-01 is a large, carefully controlled study involving patients with early-stage breast cancer at high risk of recurrence. It is testing GLSI-100 against a placebo in about 750 patients, looking primarily at whether it can prolong the time without cancer recurrence. Patients in the trial receive GLSI-100 through skin injections over three years, with the hope of achieving a significant reduction in cancer recurrence.
Previously, early-phase research showed promising results, with no cancer recurrences in a specific patient group after five years, suggesting a strong immune response to the treatment. The current phase 3 trial is an expansion of this effort, with plans to include more clinical sites, especially in Europe, to speed up enrollment and refine the study’s analysis.
