About Phase4 Partners
Phase4 Partners is a venture capital firm founded in 1999. It is primarily based out of London, United Kingdom. As of Apr 2015, Phase4 Partners has invested in 27 companies. It primarily invests in Post IPO round in United States based startups. Its investments are spread across a wide range of sectors from Life Sciences to High Tech and Enterprise Applications. Most recently it participated in the $***** Series B round of Nabriva Overall, Phase4 Partners portfolio has seen 6 IPOs and 12 acquisitions including key companies like Valneva, Acadia and Paratek Pharma. A lot of funds co-invest with Phase4 Partners, with names like Aisling Capital sharing a substantial percentage of its portfolio. Phase4 Partners has team of 1 people including 1 partners.Key Metrics
Team Members
Portfolio Sectors
Portfolio Locations
Rounds of Entry
PE, Post IPO & 2 more
Portfolio IPOs
Portfolio Acquisitions
Phase4 Partners' List of Top Investments
Phase4 Partners has a portfolio of 27 companies. Their most notable investmentis in Catalyst BiosciencesTheir portfolio spans across United States, United Kingdom, Austria and 5 more locations. They have invested in Life Sciences, High Tech, Enterprise Applications and 3 other sectors, across stages such as PE, Post IPO and 2 more. Here is the list of top investments by Phase4 Partners:1. Valneva
Developer of prophylactic vaccines for infectious diseases. The company's lead candidate is VLA1553 is a live-attenuated, single dose vaccine targeting the chikungunya virus. Other products includes VLA15 for Lyme Disease, VLA84 for Clostridium difficile, and VLA1601 for zika virus
Key facts about Valneva
- Founded Year: 1999
- Location: Lyon (France)
- Stage: Public
- Total Funding till date: $114M
- Employee Count: 637 as on May 31, 2026
- Investors: Deep Track Capital, Phase4 Partners and 13 Others
- Latest Funding Round: Post IPO, Oct 05, 2022, $*****
- Highlight: Public
2. Acadia
Developer of therapeutics for central nervous system disorders. The company develop therapies for hallucinations and delusions associated with Parkinson’s disease psychosis and for the treatment of Rett syndrome
Key facts about Acadia
- Founded Year: 1993
- Location: San Diego (United States)
- Annual Revenue: $1B+ as on Dec 31, 2025
- Stage: Public
- Total Funding till date: $44.7M
- Employee Count: 1,000 as on May 31, 2026
- Investors: Phase4 Partners, ACl Fund and 12 Others
- Latest Funding Round: Post IPO, Jan 06, 2016, $*****
- Highlight: Public
Developer of therapeutics for antimicrobial resistant infections. The company's lead candidate is NUZYRA(omadacycline), an oral and intravenous antibiotic for the treatment of adults with Community-Acquired Bacterial Pneumonia (CABP) and Acute Bacterial Skin and Skin Structure Infection (ABSSSI) caused by select susceptible microorganisms. Other drugs include Seysara for the treatment of inflammatory lesions of non-modular moderate to severe acne vulgaris.
Key facts about Paratek Pharma
- Founded Year: 1996
- Location: Boston (United States)
- Annual Revenue: $100M - $500M as on Dec 31, 2022
- Last Known Valuation: $*****
- Stage: Acquired
- Total Funding till date: $96.5M
- Employee Count: 427 as on May 31, 2026
- Investors: HBM Healthcare Investments, Phase4 Partners and 25 Others
- Latest Funding Round: Grant (prize money), Sep 27, 2021, $*****
- Highlight: Acquired
4. Nabriva
Nabriva Therapeutics is developing pleuromutilin class of antibiotics for MDR infections. Its lead product candidate is Lefamulin for treating acute bacterial skin and skin structure infections (phase II); intravenous and oral formulations for the treatment of community-acquired bacterial pneumonia (CABP) (FDA approved); for pediatric indications (phase I), STI, osteomyelitis, HABP/VABP, and prosthetic joined infections (phase I). The antibiotic binds to a specific site on the bacterial ribosome responsible for bacterial protein synthesis. It has also developed Contepo (IV) for treating cUTI (NDA/MAA filing) and pediatric indications (phase I).
Key facts about Nabriva
- Founded Year: 2006
- Location: Vienna (Austria)
- Annual Revenue: $10M - $50M as on Dec 31, 2022
- Stage: Public
- Total Funding till date: $193M
- Employee Count: 51 - 200 as on Jul 01, 2024
- Investors: HBM Healthcare Investments, Phase4 Partners and 18 Others
- Latest Funding Round: Conventional Debt, Dec 21, 2018, $*****
- Highlight: Public
Developer of novel bile acid modulators to treat gastrointestinal diseases. It offers bile acid modulators to treat orphan pediatric liver diseases and other liver and gastrointestinal disorders. Its clinical pipeline includes Elobixibat and Bylvay potent and selective ileal bile acid transporter, and A4250 a IBAT inhibitor for cholestatic liver disease.
Key facts about Albireo Pharma
- Founded Year: 2008
- Location: Gothenburg (Sweden)
- Annual Revenue: $10M - $50M as on Dec 31, 2021
- Last Known Valuation: $*****
- Stage: Acquired
- Total Funding till date: $40M
- Employee Count: 3 as on Feb 28, 2021
- Investors: Phase4 Partners, Kreos Capital and 6 Others
- Latest Funding Round: Grant (prize money), Sep 18, 2012, $*****
- Highlight: Acquired
Phase4 Partners' Investments by Stage
Phase4 Partners has made 1 investment in PE stage with an average round size of $50.8M, 1 investment in Post IPO stage with an average round size of $40M, 1 investment in Series A stage with an average round size of $70M and 1 investment in Series B stage with an average round size of $33M.Stage of entry | No. of Investments |
|---|---|
PE | 1 |
Post IPO | 1 |
Series A | 1 |
Series B | 1 |
Note: We have considered here, only first round of investments
Phase4 Partners' Investments by Sector
Phase4 Partners has a diverse portfolio, with companies operating in the Life Sciences and Sustainability Tech. Notably, it has invested in 20 Tech companies, 17 Enterprise (B2B) companies, 2 Consumer (B2C) companies and at least 2 companies focusing on Software.Sector | No. of Investments |
|---|---|
Life Sciences | 4 |
Sustainability Tech | 2 |
Note: We have considered here, only first round of investments
Phase4 Partners' Investments by Geography
Phase4 Partners has made most investments in United States (3), followed by Austria where it has made 1 investment.Country | No. of Investments |
|---|---|
United States | 3 |
Austria | 1 |
Note: We have considered here, only first round of investments
Phase4 Partners' recent investments
Phase4 Partners has not made any investment in 2026 so far.Here are the most recent investments by Phase4 Partners:
Filter this listDate | Company | Location | Round Details | Round Amount | Co-Investors |
|---|---|---|---|---|---|
Apr 07, 2015 | Austria | Series B | 9479 | [+6] | |
Oct 28, 2009 | Austria | PE | 2897 | [+3] | |
Oct 25, 2007 | United States | Post IPO | 2146 | [+8] | |
Jan 31, 2006 | Austria | PE | 9825 | [+3] | |
Oct 25, 2005 | United States | Series A | 3936 |
IPOs and Publicly Listed companies in Phase4 Partners' Portfolio
6 of Phase4 Partners' portfolio companies have become public. Nabriva got listed on the National Association of Securities Dealers Automated Quotations (NASDAQ), in Jun 2017 at marketcap of $203M and AVANT Immunotherapeutics got listed on the National Association of Securities Dealers Automated Quotations (NASDAQ).Here are Phase4 Partners' portfolio companies that went public:
Company | IPO Date | First Invested on | First Round of Investment | Round Size |
|---|---|---|---|---|
Jun 27, 2017 | Jan 31, 2006 | PE | 6689 | |
Oct 01, 2008 | - | - | 8858 | |
Nov 07, 2007 | - | - | 8328 | |
Jun 01, 2007 | - | - | 8384 | |
Apr 13, 2006 | Dec 10, 2004 | Series B | 9902 |
Acquired companies in Phase4 Partners' Portfolio
12 companies from Phase4 Partners' portfolio have been acquired. The most recent acquisition was Paratek Pharma in Jun 2023 by Gurnet Point Capital for $*****.Here are Phase4 Partners' portfolio companies that got acquired most recently:
Company | Acquisition Date | First Invested on | First Round of Investment | Round Size |
|---|---|---|---|---|
Jun 06, 2023 | Oct 25, 2007 | Post IPO | 3288 | |
Jan 09, 2023 | - | - | 1571 | |
Dec 05, 2018 | - | - | 1926 | |
Apr 13, 2018 | - | - | 4047 | |
Jul 27, 2016 | - | - | 5796 |
Team profile of Phase4 Partners
Phase4 Partners has a team of 1 member located in United Kingdom. Phase4 Partners' team does not sit on the board of any company as of now.Co-investors of Phase4 Partners
Over the past 22 years, 48 investors have co-invested in Phase4 Partners's portfolio companies. This includes only funds.
- Invested before Phase4 Partners: Auriga Partners, Nomura and 13 others have invested in rounds before Phase4 Partners. There is 1 company where Auriga Partners has invested before Phase4 Partners and 1 company where Nomura has invested before Phase4 Partners.
- Top Co-investors of Phase4 Partners: 14 investors entered a company along with Phase4 Partners. These include investors like Aisling Capital (1 company).
- Invested after Phase4 Partners: A total of 19 investors have invested in Phase4 Partners's portfolio after their investments. Top Investors include Abingworth (1 company), The Baupost Group (1 company) and HBM Healthcare Investments (1 company).
Recent News related to Phase4 Partners
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Cerimon Pharmaceuticals Raises $70 Million in Series A FinancingPR Newswire•Oct 26, 2005•Cerimon Pharmaceuticals, Orbimed, Phase4 Partners
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PE Week Wire - Friday, December 10 - PE HubPE Hub•Dec 10, 2004•Inimex Pharmaceuticals, BDC, Advent Solar, EnerTech Capital and 8 others
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The Business Journals•Paratek Pharma, Aisling Capital, Novartis Venture Fund, HBM Healthcare Investments and 8 others
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