Greenwich LifeSciences, Inc.

What they do

Greenwich LifeSciences is focused on its Phase III clinical trial, Flamingo-01, evaluating GLSI-100, an immunotherapy combining the GP2 peptide (derived from the HER2/neu protein) with GM-CSF. The trial targets HER2/neu-positive breast cancer patients with residual disease or high-risk pathologic complete response after surgery and trastuzumab-based treatment. The company has no marketed products and has not generated any revenue to date.

Recent performance

For the six months ended June 30, 2026, net loss was $9.6 million versus $6.5 million in the same period of 2025. Research and development expenses increased 54% year-over-year to $8.77 million, driven by an options grant and higher clinical expenses. General and administrative expenses increased 31% to $462,931 for the three months ended June 30, 2026. As of June 30, 2026, cash and equivalents totaled $8.9 million, with total assets of $8.9 million and shareholder equity of $3.1 million. Annual net losses widened from $17.4 million in 2024 to $19.4 million in 2025.

Strategy

Management is expanding the Flamingo-01 trial into Europe, with plans to open up to 150 sites globally. The company is investing in clinical development and preparing for potential commercialization. It expects to continue incurring significant expenses and operating losses as it conducts trials and seeks regulatory approval. It relies on a single manufacturer for GM-CSF supply, which is critical for its trials and potential commercialization.

Risks

• Going concern and capital needs — The company has a substantial accumulated deficit ($87.1 million as of December 31, 2025) and expects to continue incurring increasing losses, requiring substantial additional capital to fund operations.
• No revenue or approved products — Greenwich has not generated any revenue from product sales or collaborations and is entirely dependent on the success of its Phase III trial for GLSI-100.
• Single-source GM-CSF supply — GM-CSF is available exclusively from one manufacturer, and any disruption in supply could halt clinical trials or delay commercialization.
• Regulatory and clinical uncertainty — The product candidate may fail to prove safe or effective in clinical trials, and regulatory approval is not guaranteed, which could lead to a total loss of investment.

Outlook

Management expects to continue incurring significant expenses and increased operating losses as it advances Flamingo-01 and builds infrastructure for potential commercialization. The company is expanding trial sites in Europe and aims to open up to 150 globally. No revenue is expected for many years, if at all.