Greenwich LifeSciences, Inc.
GLSI evidence brief
What we can confirm
What it means
What to watch
Prepared research question
What matters most for GLSI—catalysts, financial risk and supporting evidence?
Traceable citations · Unknowns marked
BioSniper AI · GLSI
Greenwich LifeSciences, Inc. (GLSI) is a clinical-stage biopharmaceutical company developing GLSI-100, an immunotherapy for HER2/neu-positive breast cancer, currently in a Phase III trial (Flamingo-01) with no approved products or revenue to date.
Key risk: No revenue and recurring losses
BioSniper Score
Based on 6 of 6 signals
Market Cap
$230.0M
Cash Runway
13.7 moLead Asset
glsi-100 (Phase 3)Next Catalyst
Phase3_Topline · Dec 1, 2031Financial data as of Jun 30, 2026.
Tracking 1 pipeline candidate · 1 clinical trial · 1 catalyst for Greenwich LifeSciences, Inc..
Greenwich LifeSciences, Inc. (GLSI) is a clinical-stage biopharmaceutical company developing GLSI-100, an immunotherapy for HER2/neu-positive breast cancer, currently in a Phase III trial (Flamingo-01) with no approved products or revenue to date.
- Greenwich LifeSciences is a clinical-stage biopharmaceutical company focused on its Phase III clinical trial, Flamingo-01, evaluating GLSI-100, an immunotherapy to prevent breast cancer recurrences [sec_mda · as of 2026-06-01].
- GP2 is a 9 amino acid transmembrane peptide of the HER2/neu protein, expressed in 75% of breast cancers at low, intermediate, and high levels [sec_mda · as of 2026-06-01].
- The company has not generated any revenue and has incurred net losses; net loss was $3.9M for the six months ended June 30, 2026 [sec].
- Cash and equivalents were $8.9M as of June 30, 2026 [sec].
- The Flamingo-01 trial is being expanded into Europe with plans to open up to 150 sites globally [sec_mda · as of 2026-06-01].
What works
- GLSI-100 targets HER2/neu, a protein expressed in 75% of breast cancers, offering a broad potential patient population [sec_mda · as of 2026-06-01].
- The Phase III Flamingo-01 trial is actively enrolling and expanding into Europe, with a planned global site network of up to 150 sites [sec_mda · as of 2026-06-01].
- The company has a defined catalyst timeline with a Phase 3 topline readout expected by December 2031 [upcoming catalysts].
What to weigh
- The company has no approved products and has not generated any revenue to date [sec_mda · as of 2026-08-11].
- Net losses have been increasing, with a net loss of $3.9M for the six months ended June 30, 2026, and accumulated deficits from prior years [sec] [sec_mda · as of 2026-08-11].
- Cash and equivalents of $8.9M as of June 30, 2026 may be insufficient to fund the Phase III trial to completion without additional financing [sec].
- The Phase III trial is still in early stages of global expansion, and topline results are not expected until 2031, creating a long development timeline [upcoming catalysts].
From the filings
Quoted directly from source documents.
The company is focused on a Phase III trial for GLSI-100, an immunotherapy for breast cancer.
“We are a clinical-stage biopharmaceutical company focused on our Phase III clinical trial, Flamingo-01, which is evaluating GLSI-100, an immunotherapy to prevent breast cancer recurrences.”
SEC MD&A · June 1, 2026
GP2 is a peptide of the HER2/neu protein, expressed in 75% of breast cancers.
“GP2 is a 9 amino acid transmembrane peptide of the HER2/neu protein, a cell surface receptor protein that is expressed in a variety of common cancers, including expression in 75% of breast cancers at low (1+), intermediate (2+), and high (3+ or over-expressor) levels.”
SEC MD&A · June 1, 2026
The company has not generated any revenue and has incurred net losses.
“To date, we have not generated any revenue and we have incurred net losses.”
SEC MD&A · August 11, 2026
Catalyst timeline
- 2031-12-01 · Phase3_Topline — Topline results from the Phase 3 Flamingo-01 trial evaluating GLSI-100 in HER2/neu-positive breast cancer patients are expected.
Risks & what to watch (4)›
Key risks
- No revenue and recurring losses — The company has no approved products and has not generated any revenue, with net losses of $3.9M for H1 2026 [sec].
- Cash runway uncertainty — Cash of $8.9M as of June 30, 2026 may be insufficient to complete the Phase III trial without additional financing [sec].
- Long development timeline — Phase 3 topline results are not expected until December 2031, exposing the company to prolonged clinical and regulatory risk [upcoming catalysts].
- Clinical trial execution risk — The Flamingo-01 trial is expanding into Europe with up to 150 sites, which may face enrollment and operational challenges [sec_mda · as of 2026-06-01].
What to watch
- Enrollment progress and site expansion of the Phase III Flamingo-01 trial, particularly in Europe [sec_mda · as of 2026-06-01].
- Cash position and any future financing or partnership announcements to support the trial through to topline results [sec].
- Regulatory updates or interactions with the FDA regarding the GLSI-100 development pathway.
- Any interim data or safety updates from the Flamingo-01 trial that may inform efficacy or risk profile.
Sources: SEC MD&A · Generated August 26, 2026 · How we verify sources →
Run Greenwich LifeSciences, Inc. through your own thesis
Use the pipeline, catalyst, financial, FDA, and market facts on this page as inputs to a protocol you control.
Your protocol can:
- Turn available Greenwich LifeSciences, Inc. facts into screen rules or deeper checks
- Show cited findings, blockers, and unresolved evidence together
- Save the logic and rerun it as the company evidence changes
Evidence & data
Score breakdownBased on 6 of 6 signals · derived from public data
13.7 months
D/E 1.85 · 0% dilution
Lead: Phase 3
1 candidate
1 upcoming, next in ~1919d
5 buys · 0 sells (180d)
Runway
Catalysts
Pipeline
Regulatory
Financials
Institutional Holdings
Source: SEC Form 13F · as of Mar 2026Institutional holders
62
Total value held
$45.2M
| Holder | Shares | Value |
|---|---|---|
| vanguard capital management llc | 596,532 | $14.3M |
| blackrock, inc. | 433,860 | $10.4M |
| geode capital management, llc | 155,466 | $3.7M |
| state street corp | 133,875 | $3.2M |
| northern trust corp | 75,125 | $1.8M |
| vanguard portfolio management llc | 58,911 | $1.4M |
| bank of new york mellon corp | 46,523 | $1.1M |
| vanguard fiduciary trust co | 44,908 | $1.1M |
| goldman sachs group inc | 39,521 | $949K |
| ancora advisors llc | 37,500 | $901K |
Showing top 10 of 62 institutional holders of Greenwich LifeSciences, Inc.. Open the full 13F history after sign-in.
Short Interest
as of May 21, 2026- % of float
- 22.5%
- Days to cover
- 11.6
- Shares short
- 1,544,439
- Daily short volume
- -
Short percent of float and days-to-cover reflect reported short positioning. Daily short volume is the exchange-reported short share of a single day's trading volume and is noisier. See the most-shorted biotech ranking →
GLSI short interestGovernance
Frequently asked questions
What is the AI investment thesis for Greenwich LifeSciences, Inc.?
Greenwich LifeSciences, Inc. (GLSI) is a clinical-stage biopharmaceutical company developing GLSI-100, an immunotherapy for HER2/neu-positive breast cancer, currently in a Phase III trial (Flamingo-01) with no approved products or revenue to date.
What is Greenwich LifeSciences, Inc.'s lead drug candidate?
Greenwich LifeSciences, Inc.'s most advanced tracked candidate is glsi-100 (Phase 3) for Breast Cancer.
What is Greenwich LifeSciences, Inc.'s next catalyst?
Greenwich LifeSciences, Inc.'s next tracked catalyst is a Phase3_Topline event — "Phase 3 Topline: A Randomized, Multicenter, Placebo-controlled, Phase 3 Study to Evaluate the Efficacy and Safety of " — expected December 1, 2031.
Who is the CEO of Greenwich LifeSciences, Inc.?
Mr. Snehal S. Patel is the chief executive officer of Greenwich LifeSciences, Inc. (GLSI).
Where is Greenwich LifeSciences, Inc. headquartered?
Greenwich LifeSciences, Inc. (GLSI) is headquartered in Stafford, TX, United States.
The AI overview and BioSniper Score are neutral, data-derived signals built from public SEC filings, ClinicalTrials.gov and FDA records — not investment advice.