David Buller’s career spans from healthtech entrepreneur to leading venture capitalist in digital health. David brings to KELES a proven track record in business building, strong investment returns, an extensive international network, and access to unique deal flow. His ability to identify world-class innovation strengthens KELES’ capacity to deliver robust returns in the global market. David’s latest achievement as one of the founders of Ascension Life Fund focused on digital health in the UK, is another stepping stone for KELES’ success.
David and Laurent partnered after Laurent left Sanofi, spending 2023 establishing KELES, analysing over 3,000 European startups and identifying more than 1,000 that fit their investment thesis. They spent the following year refining their thesis and collaborating with investors and entrepreneurs before launching KELES as a new venture capital firm focused on European digital health growth-stage companies.The firm combines David’s operational and VC expertise with Laurent’s deep knowledge of global pharma and healthcare.
Venture Capital Experience
David was the founder of Avantec Healthcare, a provider of robotic drug dispensing and inventory management systems for hospitals. After scaling the company to 50 staff and annual revenues exceeding $10 million, Avantec was acquired by Omnicell (NASDAQ: OMCL) in 2015. Following the acquisition, David worked with Omnicell, helping integrate Avantec into the global public company while supporting business development in Europe, the Middle East, and APAC.
In 2018, David transitioned into venture capital. Moving to San Francisco, he immersed himself in the Silicon Valley startup ecosystem. He studied venture capital at UC Berkeley and the National Venture Capital Association, while becoming an active investor with angel groups like the Band of Angels, Jason Calacanis’ Launch, and 500 Global, where he also served as a mentor and Entrepreneur in Residence. Over time, David built a significant angel investment portfolio across various sectors and stages, both in the UK and the US. To date, he has made direct and indirect investments in more than 200 companies.
David’s venture capital career took a major step forward when he joined Ascension Ventures in 2018 as a shareholder and Venture Partner. Ascension, with over £100m in assets under management and 150 portfolio companies, was recognised in 2022 as ‘London’s Most Active VC’ and ‘Seed Investor of the Year’.
In 2020, David co-founded the Ascension Life Fund, focusing exclusively on techbio and digital health. The Life Fund built a portfolio of 17 investments in two years, achieving strong performance. One of its techbio investments, Aparito, was recently acquired by Eli Lilly. David’s broader investments in deep tech and AI have delivered market-leading returns, providing him with a keen eye for the most promising and value-creating technologies.
Having successfully deployed the Life Fund, David was eager to build on this momentum. Recognising a significant opportunity to scale his work, he sought to expand his investment strategy beyond the UK to Europe, with a focus on later-stage companies. This vision aligned perfectly with Laurent’s aspirations for a European digital health fund and together, they launched KELES, marking the beginning of a new chapter.