# Cary Pfeffer

> Cary Pfeffer is a Series A investor at Third Rock Ventures backing Biotechnology and Health Care. See 9 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [Third Rock Ventures](https://shizune.co/investors/profile/third-rock-ventures)
- Location: Boston, United States
- Total investments: 9
- Last investment: Nov 2022
- Lead investor: 56%
- Last updated: Aug 2026
- LinkedIn: https://www.linkedin.com/in/cary-pfeffer-a5083116/

Cary Pfeffer is a Series A investor at Third Rock Ventures in Boston focused on Biotechnology and Health Care. Cary Pfeffer is the interim CEO of Jounce Therapeutics and partner of Third Rock Ventures. Dr. Pfeffer has more than 20 years of business development and transaction experience, facilitating the successful development and implementation of leading collaborations across the spectrum of newly emerging and established biotech companies. He joinedThird Rock Ventures in 2007 and drives the firm's overall interface strategy with pharmaceutical and large biotech companies as well as academic institutions. Additionally, he supports the business development efforts within Third Rock's portfolio companies and is a board member of Eleven Biotherapeutics, Ablexis, Edimer and Taris Biomedical. Before joining Third Rock Ventures, Dr. Pfeffer founded The Pfeffer Group, which provided business development and strategy advisory services for leading biotechnology and life sciences companies. Prior to that, he spent more than 10 years at Biogen in a variety of executive domestic and international management roles focused on business and market development, product development and commercial operations. Earlier in his career, Dr. Pfeffer spent several years in corporate finance in the Health Care Investment Banking Group of Lehman Brothers.Dr. Pfeffer holds an M.D. from the University of Pennsylvania, an M.B.A. from the Wharton School and a B.A. in biochemistry from Columbia University.

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Biotechnology | 5 | 56% |
| Health Care | 4 | 44% |
| Therapeutics | 2 | 22% |
| Medical Device | 2 | 22% |
| Pharmaceutical | 1 | 11% |

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Series A | 4 | 44% |
| Series B | 2 | 22% |
| Series C | 1 | 11% |
| Funding Round | 1 | 11% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Casma Therapeutics | Casma Therapeutics is a developer of a natural cellular process of autophagy to open new target areas for drug discovery and development. The company focuses on autophagy system to improve the cellular process of clearing out unwanted proteins, organelles and invading pathogens as well as tries to arrest or reverse the progression of lysosomalstorage disorders, muscle disorders, inflammatory disorders and neurodegeneration, enabling physicians to address unmet medical needs. | $46M | Series C | Nov 15, 2022 |  |
| Faze Medicines | Faze Medicines is a biotechnology company harnessing the groundbreaking new science of biomolecular condensates to create medical breakthroughs. | $81M | Series A | Dec 10, 2020 |  |
| Casma Therapeutics | Casma Therapeutics is a developer of a natural cellular process of autophagy to open new target areas for drug discovery and development. The company focuses on autophagy system to improve the cellular process of clearing out unwanted proteins, organelles and invading pathogens as well as tries to arrest or reverse the progression of lysosomalstorage disorders, muscle disorders, inflammatory disorders and neurodegeneration, enabling physicians to address unmet medical needs. | $50M | Series B | Sep 10, 2020 |  |
| Casma Therapeutics | Casma Therapeutics is a developer of a natural cellular process of autophagy to open new target areas for drug discovery and development. The company focuses on autophagy system to improve the cellular process of clearing out unwanted proteins, organelles and invading pathogens as well as tries to arrest or reverse the progression of lysosomalstorage disorders, muscle disorders, inflammatory disorders and neurodegeneration, enabling physicians to address unmet medical needs. | $58.5M | Series A | May 03, 2018 |  |
| TARIS Biomedical | TARIS Biomedical a specialty pharmaceutical company with deep domain expertise in therapeutics and drug-delivery, is focused on local minimally-invasive drug-device convergence products. The TARIS core technology and development efforts are being applied to disease areas with high unmet medical need in which current therapies or systemic treatmentshave failed. | $13.5M |  | Mar 18, 2013 |  |
| Sesen Bio | Sesen Bio, Inc.. is a late clinical-stage company advancing a broad pipeline of novel anti-cancer agents based on their Targeted Protein Therapeutics (TPTs) platform. Their TPTs genetically combine targeting antibody fragments with cytoxic protein payloads to create a single fusion protein through Eleven's proprietary one-step manufacturingprocess. | $20M | Series A | May 08, 2012 |  |
| TARIS Biomedical | TARIS Biomedical a specialty pharmaceutical company with deep domain expertise in therapeutics and drug-delivery, is focused on local minimally-invasive drug-device convergence products. The TARIS core technology and development efforts are being applied to disease areas with high unmet medical need in which current therapies or systemic treatmentshave failed. | $18.4M | Series B | Apr 13, 2011 |  |
| Ablexis | Ablexis, LLC, a biotechnology company dedicated to developing an innovative, next-generation platform for antibody drug discovery, was founded in December 2009, based on technology principles established by its subsidiary, Aliva Biopharmaceuticals, Inc. | $12M | Series A | Jun 02, 2010 |  |
| Sesen Bio | Sesen Bio, Inc.. is a late clinical-stage company advancing a broad pipeline of novel anti-cancer agents based on their Targeted Protein Therapeutics (TPTs) platform. Their TPTs genetically combine targeting antibody fragments with cytoxic protein payloads to create a single fusion protein through Eleven's proprietary one-step manufacturingprocess. | $35M | Series A | Mar 09, 2010 |  |

9 of 9 investments shown.

## Co-investors
- [Flagship Pioneering](https://shizune.co/investors/profile/flagship-ventures) — VC Fund, 3 deals together
- [The Column Group](https://shizune.co/investors/profile/the-column-group) — VC Fund, 2 deals together
- [AbbVie Biotech Ventures](https://shizune.co/investors/profile/abbvie-biotech-ventures) — VC Fund, 1 deal together
- [Alexandria Venture Investments](https://shizune.co/investors/profile/alexandria-venture-investments) — VC Fund, 1 deal together
- [Amgen Ventures](https://shizune.co/investors/profile/amgen-ventures) — VC Fund, 1 deal together
- [Astellas Venture Management](https://shizune.co/investors/profile/astellas-venture-management) — VC Fund, 1 deal together

## About Third Rock Ventures

VC Fund · Boston, United States

Third Rock Ventures invests in transformational life science companies that show high growth potential and are well-positioned to make a difference in the marketplace. Third Rock Ventures believes in the companies we start and makes significant initial investments, which are frequently supplemented by strategic collaborations, to help our firmsprogress in life-changing medicines, technologies, and diagnostics.

5 contacts available at Third Rock Ventures.

| Name | Title | Profile |
| --- | --- | --- |
| Cary Pfeffer | Partner | https://shizune.co/investors/profile/cary-pfeffer |
| Jeff Tong | Partner | https://shizune.co/investors/profile/jeff-tong |
| Jigar Raythatha | Partner | https://shizune.co/investors/profile/jigar-raythatha |
| Mark Levin | Partner | https://shizune.co/investors/profile/mark-levin |
| Reid Huber | Partner | https://shizune.co/investors/profile/reid-huber |

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## FAQ

### What does Cary Pfeffer invest in?

Cary Pfeffer invests primarily in Biotechnology, Health Care and Therapeutics startups, most often at Series A and Series B stage. Most of the 9 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### When did Cary Pfeffer last invest?

The most recent investment recorded for Cary Pfeffer closed in Nov 2022. Shizune tracks 9 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.

### Is Shizune's investor data accurate?

Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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