Longwood Fund is a Boston-based venture capital firm founded in 2010 that creates and invests in science-based healthcare and biotechnology companies developing novel solutions for important unmet medical needs. The firm co-founds and operationally supports companies from inception through early stages.
60% of their portfolio is in Biotech & Life Sciences. Deal activity increased 80% year-over-year (9 deals in the last 12 months). Their most common stage is series-a (40% of deals). Average disclosed round size is $83.4M (across 74 rounds with reported amounts).
Portfolio
57
Fund Size
$180M
Top Stage
Series A
Last 12 Mo
9
Team
Christina Stephens
Executive Assistant
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
84 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 Khartis Therapeutics | Series B | $50M | Aug 2026 |
 Crystalys Therapeutics Inc | Series B | $130M | Jul 2026 |
 Coultreon Biopharma | Series A | $125M | Apr 2026 |
 Neomorph | Series B | $100M | Apr 2026 |
 Sidewinder | Series B | $137M | Apr 2026 |
 Mediar | Series B | $76M | Jan 2026 |
| SSidewinder Therapeutics | Series B | $137M | Jan 2026 |
| Sidewinder | Series B | $137M | Jan 2026 |
 Coultreon Biopharma | Series A | $125M | Jan 2026 |
| Coultreon Biopharma | Series A | $125M | Jan 2026 |
 AAVantgarde Bio | Series B | — | Nov 2025 |
| Crystalys Therapeutics Inc | Series A | $205M | Sep 2025 |
 Avenzotx | Series B | $60M | Sep 2025 |
 Solu | Series A | $41M | Apr 2025 |
| SSolu Therapeutics | Series A | $41M | Apr 2025 |
| Coultreon Biopharma | Seed | — | Apr 2025 |
 Newleos | Series A | $93.5M | Feb 2025 |
| NNewleos Therapeutics | Series A | $93.5M | Feb 2025 |
 Avenzo Therapeutics | Series B | $60M | Jan 2025 |
| Newleos | Series A | $93M | Jan 2025 |
| NNewleos Therapeutics | Series A | $93.5M | Jan 2025 |
| Coultreon Biopharma | Seed | — | Jan 2025 |
 Evommune | Series C | $115M | Oct 2024 |
 Progentos Therapeutics | Series A | $65M | May 2024 |
 BridgeBio Oncology Therapeutics (BBOT) | Growth | $200M | May 2024 |
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Top Co-Investors
Alexandria Venture Investments17 shared
Sofinnova Partners14 shared
RA Capital Management12 shared
Forbion12 shared
Arkin Bio Ventures11 shared
Novartis Venture Fund11 shared
SR One10 shared
Novo Holdings A/S10 shared
Cormorant Asset Management9 shared
Astellas Venture Management9 shared
GV8 shared
Bessemer Venture Partners8 shared
Atlas Venture8 shared
MPM Capital7 shared
Perceptive Advisors7 shared
Pivotal Life Sciences6 shared
Agent Capital6 shared
DCVC6 shared
Frazier Life Sciences6 shared
Samsara BioCapital6 shared
Last updated: 7 October 2026