# Joel Mairet

> Joel Mairet is a Series B investor at Ysios Capital (Barcelona) backing Biotechnology and Medical. See 19 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [Ysios Capital](https://shizune.co/investors/profile/ysios-capital)
- Location: Barcelona, Spain
- Total investments: 19
- Last investment: Jun 2026
- Lead investor: 26%
- Last updated: Aug 2026
- LinkedIn: https://www.linkedin.com/in/jo%C3%ABl-jean-mairet-956667/

Joel Mairet is a Series B investor at Ysios Capital in Barcelona focused on Biotechnology and Medical. Joël oversees all operations at Ysios Capital, including management, strategy and standard operations.Joël serves on the board of TiGenix, AM-Pharma, MedLumics, and is chairman of the board at Inbiomotion. Formerly, he was board observer at Biovex (now AMGEN) and chairman of the board at Cellerix (now TiGenix).Previously, Joël co-foundedGLYCART Biotechnology AG (Zürich, Switzerland) in March 2001 and was Chief Executive since inception. He raised €15 million in three rounds of financing for GLYCART before the company was sold to F.Hoffmann-La Roche Ltd in July 2005, a deal lauded as the deal of the year by the European Venture Capital magazine. As Chief Executive, he led all the fund-raising efforts, established a pan-European investment syndicate with leading venture capital firms and structured, negotiated and executed several key in- and out-licensing agreements with global pharmaceutical and biotechnology companies.Joël holds a master’s degree in Biochemistry, with a specialization in Biotechnology, and a PhD in the fields of cell biology and immunotherapeutics, both from the Swiss Federal Institute of Technology (ETH) in Zürich. He was elected one of the 50 key players in biotechnology in Switzerland in 2003 and earned several innovation awards for GLYCART, including the Wall Street Journal Europe Innovation Award in 2001.

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Biotechnology | 9 | 47% |
| Medical | 5 | 26% |
| Pharmaceutical | 5 | 26% |
| Health Care | 4 | 21% |
| Life Science | 3 | 16% |

11 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Series B | 7 | 37% |
| Series A | 4 | 21% |
| Venture - Series Unknown | 3 | 16% |
| Series C | 2 | 11% |
| Series F | 1 | 5% |

6 stages tracked in total.

### Country

| Country | Investments | Share |
| --- | --- | --- |
| Spain | 4 | 21% |
| United States | 2 | 11% |
| The Netherlands | 2 | 11% |
| Denmark | 1 | 5% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Ona Therapeutics | Ona Therapeutics is a biotech company that specializes in the discovery and development of therapeutic biologics targeting tumor metastatic-initiating cells and lipid metabolism. Founded in 2019 by Salvador Aznar-Benitah and Valerie Vanhooren, it was a spin-off from ICREA and Advanced Studies, and the IRB Institute for Research in Biomedicine. | $86.6M | Series B | Jun 04, 2026 |  |
| ADCendo | ADCendo ApS is a biotech company dedicated to developing new types of anti-cancer drugs. We focus on antibody-drug conjugates (ADCs) directed at novel targets, that have been found to be overexpressed by several cancer forms, that are all characterized by a significant unmet need for novel treatment. | $75M | Series C | Apr 14, 2026 |  |
| Splice Bio | Splice Bio is a gene therapy company based on technology developed in the Muir Lab at Princeton University. The company is developing novel gene therapies based on its proprietary intein platform technology to treat patients that suffer from incurable genetic diseases. The company’s platform has the potential to address two existing limitations ofadeno-associated viruses (AAVs), both by increasing the size of the cargo gene that can be delivered and by expanding the range of tissues that can be targeted. | $135M | Series B | Jun 11, 2025 |  |
| ADCendo | ADCendo ApS is a biotech company dedicated to developing new types of anti-cancer drugs. We focus on antibody-drug conjugates (ADCs) directed at novel targets, that have been found to be overexpressed by several cancer forms, that are all characterized by a significant unmet need for novel treatment. | $135M | Series B | Nov 25, 2024 |  |
| ADCendo | ADCendo ApS is a biotech company dedicated to developing new types of anti-cancer drugs. We focus on antibody-drug conjugates (ADCs) directed at novel targets, that have been found to be overexpressed by several cancer forms, that are all characterized by a significant unmet need for novel treatment. | $34M | Series A | Apr 04, 2023 |  |
| Mineralys Therapeutics | Mineralys Therapeutics, Inc., a private, clinical-stage biopharmaceutical company founded by Catalys Pacific committed to developing best-in-class, novel therapy for the treatment of hypertension. The Company is driven to bring a targeted approach to the management of hypertension via the development of MLS-101. MLS-101, licensed from MitsubishiTanabe Pharma Corporation, is a highly selective and potent aldosterone synthase inhibitor that is being investigated for the treatment of hypertension. | $118M | Series B | Jun 08, 2022 |  |
| Splice Bio | Splice Bio is a gene therapy company based on technology developed in the Muir Lab at Princeton University. The company is developing novel gene therapies based on its proprietary intein platform technology to treat patients that suffer from incurable genetic diseases. The company’s platform has the potential to address two existing limitations ofadeno-associated viruses (AAVs), both by increasing the size of the cargo gene that can be delivered and by expanding the range of tissues that can be targeted. | $56.9M | Series A | Feb 16, 2022 |  |
| Aura Biosciences | Aura Biosciences is a biotechnology company that focuses on the development of drugs by using tumor-targeted pseudovirions. The company is applying nanotechnology to help fight cancer in the well-studied area of chemotherapeutics and the emerging field of RNAi. By safely eliminating cancer locally, they can treat early and transform the lives ofpeople with a wide range of cancers that are poorly managed today.The company's goal is to treat small ocular melanomas potentially long before the disease progresses and metastasizes to the liver, where it almost always is fatal. Aura Biosciences was founded in 2007 and is headquartered in Cambridge, Massachusetts. |  | Post-IPO Equity | Nov 03, 2021 |  |
| ADCendo | ADCendo ApS is a biotech company dedicated to developing new types of anti-cancer drugs. We focus on antibody-drug conjugates (ADCs) directed at novel targets, that have been found to be overexpressed by several cancer forms, that are all characterized by a significant unmet need for novel treatment. | $61.8M | Series A | Apr 29, 2021 |  |
| Aura Biosciences | Aura Biosciences is a biotechnology company that focuses on the development of drugs by using tumor-targeted pseudovirions. The company is applying nanotechnology to help fight cancer in the well-studied area of chemotherapeutics and the emerging field of RNAi. By safely eliminating cancer locally, they can treat early and transform the lives ofpeople with a wide range of cancers that are poorly managed today.The company's goal is to treat small ocular melanomas potentially long before the disease progresses and metastasizes to the liver, where it almost always is fatal. Aura Biosciences was founded in 2007 and is headquartered in Cambridge, Massachusetts. | $80M | Venture - Series Unknown | Mar 22, 2021 |  |

10 of 19 investments shown.

## Co-investors
- [Gilde Healthcare](https://shizune.co/investors/profile/gilde-healthcare-partners) — VC Fund, 8 deals together
- [Asabys Partners](https://shizune.co/investors/profile/asabys-partners) — VC Fund, 5 deals together
- [RA Capital Management](https://shizune.co/investors/profile/ra-capital-management) — VC Fund, 5 deals together
- [Andera Partners](https://shizune.co/investors/profile/edmond-de-rothschild-investment-partners) — VC Fund, 4 deals together
- [HealthCap](https://shizune.co/investors/profile/healthcap) — VC Fund, 4 deals together
- [Novo Holdings](https://shizune.co/investors/profile/novo-a-s) — VC Fund, 4 deals together

## About Ysios Capital

VC Fund · San Sebastian, Spain

Ysios Capital is a leading Spanish independent venture capital firm that provides private equity financing to early and mid-stage life science companies that develop disruptive therapeutic products and platform technologies. Founded in 2008, Ysios Capital manages c.a. €350 M through three dedicated funds in life sciences and is led by a team ofprofessionals experienced in building biotech companies.

5 contacts available at Ysios Capital.

| Name | Title | Profile |
| --- | --- | --- |
| Cristina Garmendia | Founding Partner and Member of the Board | https://shizune.co/investors/profile/cristina-garmendia |
| Claudia D’Augusta | Venture Partner | https://shizune.co/investors/profile/claudia-daugusta-2 |
| Guillem Laporta | Partner | https://shizune.co/investors/profile/guillem-laporta |
| Joel Mairet | Managing Partner and Co - Founder | https://shizune.co/investors/profile/joel-jean-mairet |
| Karen Wagner | General Partner | https://shizune.co/investors/profile/karen-wagner |

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## FAQ

### What does Joel Mairet invest in?

Joel Mairet invests primarily in Biotechnology, Medical and Pharmaceutical startups, most often at Series B and Series A stage. Most of the 19 investments tracked by Shizune back companies in Spain. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### When did Joel Mairet last invest?

The most recent investment recorded for Joel Mairet closed in Jun 2026. Shizune tracks 19 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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