# John Diekman

> John Diekman is a Series A investor at Bay City Capital backing Biotechnology. See 6 investments, check sizes, portfolio and contact details. Updated Sep 2026.

- Type: Angel Investor
- Fund: [Bay City Capital](https://shizune.co/investors/profile/bay-city-capital)
- Location: Menlo Park, United States
- Total investments: 6
- Last investment: May 2016
- Lead investor: 17%
- Last updated: Sep 2026
- LinkedIn: http://www.linkedin.com/pub/john-diekman/0/228/613

John Diekman is a Series A investor at Bay City Capital in Menlo Park focused on Biotechnology and Health Care. John Diekman, Ph.D. is a founder and Managing Partner of 5AM Ventures. Prior to founding 5AM, Diekman was a founder and Managing Director of Bay City Capital, a life sciences investment firm.Previously, Diekman was Chairman and CEO of Affymetrix, Inc, where he still serves as a Director. Diekman currently serves as Board Chairman of Ambrxand Phenomix as well as on the Boards of Directors of Ingenuity Systems, Marcadia, PhaseRx and Wildcat Discovery. He is also Vice-Chairman of Singapore’s Life Science Fund, Bio*One Capital. He was recently named a Trustee of Princeton University and is also former Trustee of The California Institute of Technology and The Scripps Research Institute, where he served as Chairman.Diekman holds a B.A. in Chemistry from Princeton University and a Ph.D. in Chemistry from Stanford University. Diekman is based in the Menlo Park, CA office.

## Contacts

5 contacts available for John Diekman: work email, personal email, work phone, personal phone and socials. Sign up free to unlock them: https://app.shizune.co/sign-up/investor-profiles/find-email/john-d-diekman?utm_source=investor_profile

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Biotechnology | 4 | 67% |
| Health Care | 3 | 50% |
| Therapeutics | 2 | 33% |
| Medical | 1 | 17% |
| Life Science | 1 | 17% |

6 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Series A | 3 | 50% |
| Series B | 2 | 33% |
| Series C | 1 | 17% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| IDEAYA Biosciences | IDEAYA Biosciences (IDEAYA) is an oncology-focused biotechnology company committed to the discovery of breakthrough synthetic lethality medicines targeting DNA damage and repair for genetically defined patient populations and for enhancing immunotherapy response, and immuno-oncology therapies targeting the tumor micro-environment. IDEAYA, locatedin South San Francisco and La Jolla, California, has assembled leading scientists and advisors with extensive knowledge and expertise in cancer biology and small molecule drug discovery. | $46M | Series A | May 03, 2016 | http://www.ideayabio.com/ |
| PhaseRx | PhaseRx is a startup company based in Seattle focused on the delivery of siRNA and other macromolecular therapeutics. The Company has attracted top-tier venture investors and was founded by its President, Robert Overell, Patrick Stayton and Allan Hoffman of the University of Washington, Oliver Press of Fred Hutchinson Cancer Research Center, andPaul Johnson, the Company's Chief Scientific Officer. PhaseRx was conceived on the basis of using novel polymer technology to deliver siRNA. The Company believes the technology also has significant applications for the delivery of other macromolecular therapeutics. | $20.2M | Series A | Feb 28, 2008 | http://www.phaserx.com |
| Phenomix | As of October 2010, Phenomix closed down as it was unable to find a partner to pay for is clinical trial bills after Forest Laboratories walked away. Phenomix is a drug discovery and development company building a portfolio of novel therapeutics for the treatment of major human diseases. Phenomix' lead clinical candidate, PHX1149, is aDPP4 inhibitor in phase 2 testing as a once daily oral treatment for type 2 diabetes. Phenomix' second program is directed at the treatment of hepatitis C through inhibition of the NS3/4A viral protease. Phenomix is based in San Diego, California. | $55M | Series C | Mar 08, 2007 | http://www.phenomixcorp.com |
| Phenomix | As of October 2010, Phenomix closed down as it was unable to find a partner to pay for is clinical trial bills after Forest Laboratories walked away. Phenomix is a drug discovery and development company building a portfolio of novel therapeutics for the treatment of major human diseases. Phenomix' lead clinical candidate, PHX1149, is aDPP4 inhibitor in phase 2 testing as a once daily oral treatment for type 2 diabetes. Phenomix' second program is directed at the treatment of hepatitis C through inhibition of the NS3/4A viral protease. Phenomix is based in San Diego, California. | $20M | Series B | Apr 29, 2005 | http://www.phenomixcorp.com |
| Phenomix | As of October 2010, Phenomix closed down as it was unable to find a partner to pay for is clinical trial bills after Forest Laboratories walked away. Phenomix is a drug discovery and development company building a portfolio of novel therapeutics for the treatment of major human diseases. Phenomix' lead clinical candidate, PHX1149, is aDPP4 inhibitor in phase 2 testing as a once daily oral treatment for type 2 diabetes. Phenomix' second program is directed at the treatment of hepatitis C through inhibition of the NS3/4A viral protease. Phenomix is based in San Diego, California. | $2M | Series A | Jul 20, 2004 | http://www.phenomixcorp.com |
| Phenomix | As of October 2010, Phenomix closed down as it was unable to find a partner to pay for is clinical trial bills after Forest Laboratories walked away. Phenomix is a drug discovery and development company building a portfolio of novel therapeutics for the treatment of major human diseases. Phenomix' lead clinical candidate, PHX1149, is aDPP4 inhibitor in phase 2 testing as a once daily oral treatment for type 2 diabetes. Phenomix' second program is directed at the treatment of hepatitis C through inhibition of the NS3/4A viral protease. Phenomix is based in San Diego, California. |  | Series A | Jun 30, 2003 | http://www.phenomixcorp.com |

6 of 6 investments shown.

## Co-investors
- [Alta Partners](https://shizune.co/investors/profile/alta-partners) — VC Fund, 3 deals together
- [Sofinnova Investments](https://shizune.co/investors/profile/sofinnova-ventures) — VC Fund, 3 deals together
- [CMEA Ventures](https://shizune.co/investors/profile/cmea-ventures) — VC Fund, 2 deals together
- [Delphi Ventures](https://shizune.co/investors/profile/delphi-ventures) — VC Fund, 2 deals together
- [J.P. Morgan Securities Inc.](https://shizune.co/investors/profile/j-p-morgan-securities-inc) — VC Fund, 2 deals together
- [Alexandria Real Estate Equities](https://shizune.co/investors/profile/alexandria-real-estate-equities) — VC Fund, 1 deal together

## About Bay City Capital

VC Fund · San Francisco, United States

Bay City Capital LLC (Bay City Capital) was established in 1997 for the purpose of managing investment funds in the life sciences industry. Since that date, they have managed six venture funds representing $1.5 billion in capital invested in over 70 companies. Five of these funds are general life sciences funds, and one is a nutrition andagribusiness sector fund.

5 contacts available at Bay City Capital.

| Name | Title | Profile |
| --- | --- | --- |
| David Beier | Managing Director | https://shizune.co/investors/profile/david-beier |
| Fred Gage | Scientific Advisory Board | https://shizune.co/investors/profile/fred-gage |
| Fred Craves | Managing Director | https://shizune.co/investors/profile/fred-craves |
| Judy Koh | Managing Director/Chief Financial Officer | https://shizune.co/investors/profile/judy-koh |
| Lionel Carnot | Managing Director | https://shizune.co/investors/profile/lionel-carnot |

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## FAQ

### What does John Diekman invest in?

John Diekman invests primarily in Biotechnology, Health Care and Therapeutics startups, most often at Series A and Series B stage. Most of the 6 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### How do I contact John Diekman?

Public channels for John Diekman include LinkedIn. For a verified work email and phone number, create a free Shizune account — contact data is searched across 20+ sources and validated before delivery, so your outreach lands in the right inbox.

### When did John Diekman last invest?

The most recent investment recorded for John Diekman closed in May 2016. Shizune tracks 6 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 Sep 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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