Thomas Clozel
About Thomas Clozel
Thomas Clozel is a medical doctor and the co-founder and CEO of Owkin. He founded the AI biotech company in 2016 with machine learning researcher Gilles Wainrib. Owkin builds AI systems for biomedical research and drug discovery, using multimodal patient data. It works with pharmaceutical companies including Sanofi, Bristol Myers Squibb and MSD.
Before Owkin he was an assistant professor of clinical onco-hematology at Hôpital Henri Mondor in Paris. He was also a member of Ari Melnick's oncology lab at Weill Cornell Medical College. A directory profile says he is a non-operational co-founder of Bioptimus and Cure51 and sits on the board of Université Paris-Saclay. Crunchbase places him in New York.
Crunchbase lists nine personal investments, all seed or pre-seed rounds. The earliest is Patch Biosciences in 2020. Spot and Resilience follow in 2021 and Dioxycle in 2022. Osium AI and Callyope came in 2023, altrove AI in 2024 and Grâce in April 2025. Tracxn counts eight portfolio companies, mainly in France and the United States.
He often appears as a named angel alongside funds. In Grâce's seed he is listed as a co-investor with FinTech Collective, Speedinvest and others. In altrove's announcement he is named among its angels, with Julien Chaumond of Hugging Face.
His AI-related angel investments include altrove AI, which applies AI-predicted materials discovery to industry. He invested in its pre-seed and seed rounds, and altrove later announced a $10 million raise. He also backed Osium AI in 2023.
In April 2026 he joined the angels in Modern Relay's seed round. The Lounge deals desk records the round at $2.9M (EUR 2.5M). Press reports the company as building shared infrastructure that lets enterprise AI agents work from the same company context. Point Nine led the round. Other participants were Emerge, Amino Collective, Common Magic and Masia, plus angels Charlie Songhurst and Michael Boehler.
His public record is in seed and pre-seed rounds. Tracxn lists his top sectors as HealthTech and Enterprise Applications, and a directory profile describes his interests as AI, biotech and climate. Geographically, Tracxn shows investments in France and the United States, and Modern Relay is based in San Francisco and Barcelona. No check size or written investment thesis from him is public.
- Modern Relay: shared context layer for enterprise AI agents; seed round announced April 2026.
- altrove AI: AI-predicted materials for industry; pre-seed and seed rounds, with the seed dated July 2024.
- Grâce: seed round dated April 2025.
- Osium AI: seed round dated November 2023.
- Callyope: seed round dated November 2023.
- Dioxycle: seed round dated 2022 on Crunchbase.
- Resilience and Spot: seed rounds dated March 2021 on Crunchbase.
- Patch Biosciences: seed round dated August 2020 on Crunchbase.
- crunchbase.com/person/thomas-clozel-2
- tracxn.com/d/people/thomas-clozel/__VWMkGkg8xfrDy2_nbU2IU0sgkTOzCpP5Md
- unite.ai/thomas-clozel-m-d-co-founder-and-ceo-of-owkin-interview-serie
- londontechweek.com/speakers/thomas-clozel
- askforfunding.com/investor/thomas-clozel-angel-investor
- altrove.ai/resources/seed-announcement
- pulse2.com/modern-relay-3-million-seed-funding-raised-to-build-ai-nati
- startup.eu/investments/modern-relay-3-m-seed-04-2026
Investing activity
Thomas Clozel appears in 1 AI deal tracked by the Lounge deals desk. The rounds are mostly Seed, with a median round size of $3M. The most recent is Modern Relay (Seed, $2.9M (EUR 2.5M), Apr 2026).
Thomas Clozel most often invests alongside Amino Collective, Charlie Songhurst, Common Magic and Michael Boehler, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Thomas Clozel
Who is Thomas Clozel?
He is the co-founder and CEO of Owkin, an AI biotech company founded in 2016. He trained as a physician and also invests as an angel.
Does Thomas Clozel invest in AI startups?
Yes. His public angel investments include altrove AI and Osium AI, and in April 2026 he joined the angels in Modern Relay's seed round.
What stage does Thomas Clozel invest in?
His public record is almost entirely pre-seed and seed rounds, usually alongside venture funds.
What is Thomas Clozel's check size?
It is not public. Aggregators list round sizes but not his own cheque, so this page does not state one.
Where is Thomas Clozel based and where does he invest?
Crunchbase lists him in New York. Tracxn shows his investments in France and the United States.
How can founders reach Thomas Clozel?
He has a LinkedIn profile and an X account (@TClozel). Founders usually get stronger results through a warm introduction from a shared investor or Owkin contact.
Is Thomas Clozel an angel investor?
Yes. Thomas Clozel invests personally as an angel.
What AI companies has Thomas Clozel invested in?
Thomas Clozel's AI investments include Modern Relay. The 1 round on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Thomas Clozel invest at?
In the rounds tracked on Lounge, Thomas Clozel has invested at Seed, with a median round of $3M.
Who does Thomas Clozel co-invest with?
Thomas Clozel's most frequent co-investors on Lounge are Amino Collective (1 deal), Charlie Songhurst (1 deal), Common Magic (1 deal), Michael Boehler (1 deal) and Point Nine (1 deal).