Greenwich LifeSciences (GLSI)
Runs a single Phase III trial for a peptide vaccine preventing HER2-positive breast cancer recurrence.
Something off on this page? Send us feedback.
Develops a single therapeutic candidate, GLSI-100, a peptide-based immune vaccine combining GP2 with GM-CSF designed to prevent recurrence in HER2-positive breast cancer after standard treatment. The company runs a global Phase III trial spanning roughly forty clinical sites across the US and Europe and has not yet generated product revenue, funding operations through equity issuance.
Runs on a single pipeline asset, GLSI-100, a peptide vaccine pairing the GP2 antigen with the adjuvant GM-CSF, aimed at preventing recurrence in HER2-positive breast cancer after standard treatment. The vaccine originated at a US military-linked research foundation and was in-licensed before the company's listing.
The current trial, FLAMINGO-01, is a global randomized Phase III study run mostly through academic and cooperative-group site networks across the US and Europe rather than an in-house clinical organization. It carries FDA Fast Track designation for the HLA-positive patient subgroup, and a parallel open-label arm for patients outside that subgroup has completed enrollment.
Ownership is concentrated among management and directors under an extended post-IPO lock-up, and the business remains pre-revenue, funding trials through periodic equity issuance rather than product sales. Commercial-scale manufacturing has begun, supplying ongoing dosing across the US site network.
Company facts
Target rangeAs of Sep 2, 2026
Latest analyst notes
| Date | Firm | Action | Target |
|---|---|---|---|
| Dec 30, 2025 | H.C. Wainwright | Target | $50 |
EPSReportedEstimate
RevenueReportedEstimate
Balance sheet, Jun 30, 2026Cash & short-term investments $8.9M · Total debt $0 · Total assets $8.9M · Shareholders' equity $3.1M
- Revenue
- $0
- Operating income
- −$4.0M
- Net income
- −$3.9M
No dividends on record.
| Institutions63 holders · as of Mar 31, 2026 | 11.67% | 1.71M shares | |
| Insiders4 holders · as of Jul 30, 2026 | 78.15% | 11.47M shares | |
| Otherremainder | 10.18% | 1.49M shares |
14.68M company shares as of Sep 3, 2026 · institutions as of Mar 31, 2026 · holders as of their latest filing
Top shareholders13F · 13D/G · Form 4
| Holder | Stake | Shares | Evidence |
|---|---|---|---|
Snehal Patel1Insiderdirector, 10 percent owner, officer: CEO and CFO | 56.42% | 7.78M | 13Dfiled Jul 30, 2026 ↗ |
WeinerInsider | 15.70% | 2.30M | 13Gfiled Jun 22, 2022 ↗ |
David McWilliamsInsiderdirector | 4.23% | 620,301 | Form 4filed Dec 16, 2021 ↗ |
BlackRock, Inc.Institution | 2.96% | 433,860 | 13Fas of Mar 31, 2026 |
Vanguard Capital Management LLCInstitution | 2.03% | 298,266 | 13Fas of Mar 31, 2026 |
| See all 25 → | |||
- Snehal Patel's transaction reports restate only vehicles that traded; the 2020 ownership statement (7.78M) plus the 504.0K net shares acquired since is used instead.
13F — a manager's quarterly holdings · 13D/13G — an ownership statement filed at 5% or more · Form 4 — an insider's transaction report
Insider tradesForm 4
| Date | Insider | Role | Shares | Avg price |
|---|---|---|---|---|
| Jul 28, 2026 | Snehal Patel | director, 10 percent owner, officer: CEO and CFO | +1,500 | $13.59 |
| Jul 29, 2026 | Snehal Patel | director, 10 percent owner, officer: CEO and CFO | +700 | $13.10 |
| Jul 27, 2026 | Snehal Patel | director, 10 percent owner, officer: CEO and CFO | +1,500 | $13.62 |
| Jul 23, 2026 | Snehal Patel | director, 10 percent owner, officer: CEO and CFO | +2,500 | $13.14 |
| Jul 24, 2026 | Snehal Patel | director, 10 percent owner, officer: CEO and CFO | +1,100 | $12.88 |
- AstraZeneca (ADR)
Enhertu ADC now approved for adjuvant HER2+ early-stage breast cancer
- Puma Biotechnology
Nerlynx is the only approved extended-adjuvant post-trastuzumab HER2+ therapy
- BioNTech (ADR)
Advances therapeutic cancer vaccines across mRNA and fixed-antigen platforms
- Moderna
Personalized mRNA neoantigen vaccine + Keytruda in adjuvant melanoma, Phase 3
- Novartis (ADR)
Kisqali contests adjuvant recurrence-prevention in HR+/HER2- breast cancer
ComparePre-market
| Company | Price | Change | |||||
|---|---|---|---|---|---|---|---|
| Greenwich LifeSciences | $15.68 | −0.70% | $231.0M | — | — | — | — |
| AstraZeneca (ADR) | $164.21 | +1.58% | $250.67B | 24.3 | 15.2 | 4.1 | +6.4% |
| Puma Biotechnology | $9.61 | −0.88% | $493.2M | 18.8 | — | 2.1 | +7.8% |
| BioNTech (ADR) | $104.14 | +0.36% | $26.08B | — | — | 8.5 | −60.7% |
| Moderna | $147.46 | −2.23% | $59.84B | — | — | 26.9 | +2.1% |
| Novartis (ADR) | $162.15 | −0.18% | $308.79B | 24.5 | 17.3 | 5.6 | +0.9% |
| Median | 24.3 | 16.3 | 5.6 | +2.1% |