Greenwich LifeSciences Advances Phase III Trial With FDA-Approved Commercial GP2 Supply

Greenwich LifeSciences, Inc. provided an update on its ongoing Phase III FLAMINGO-01 trial evaluating GLSI-100, an immunotherapy designed to prevent breast cancer recurrence. The company confirmed that all U.S. clinical trial sites are now using commercially manufactured GP2, the active ingredient in GLSI-100, marking a key operational milestone in the study.

The company had previously manufactured three commercial-scale lots of the GP2 active ingredient in 2023, sufficient to produce approximately 200,000 doses. In 2024, one of these lots was further processed into vial form suitable for clinical and commercial use. Stability studies were conducted across all lots, and the resulting data was submitted to the U.S. Food and Drug Administration for review. Following evaluation, the FDA approved the first commercial lot of GP2 vials for use in the FLAMINGO-01 trial in the United States.

CEO Snehal Patel commented, "We have started to submit the same manufacturing information to European, UK, and Canadian regulators so that commercially manufactured GP2 can be approved for use by all approximately 160 sites participating in FLAMINGO-01. We are also planning to manufacture additional vials of GP2, seeking a capacity of 500,000 to 1 million vials of GP2 per year, and to make larger lots of GP2 active ingredient to build inventory for a potential commercial launch."

Shortly after regulatory clearance, all approximately 40 U.S. trial sites were supplied with the commercially manufactured GP2 vials and began administering them to patients. The company highlighted efficient distribution and coordination efforts involving clinical teams, pharmacists, and warehouse partners, supported by internalised operations established in late 2025.

The update builds on encouraging results from a prior Phase IIb study conducted across multiple centres, led by MD Anderson Cancer Centre. In that trial, patients with HER2/neu 3+ breast cancer treated with GLSI-100 showed an 80% or greater reduction in cancer recurrence after five years of follow-up, provided they remained disease-free during the first six months of treatment, considered the period required to achieve peak immune response.

With the transition to commercially manufactured GP2 in the Phase III study, Greenwich LifeSciences is advancing toward potential large-scale production and commercialisation, while continuing to evaluate GLSI-100’s ability to deliver durable protection against breast cancer recurrence.