Ex-SignalFire investor raised $27.5 million for debut fund Proximal Ventures, betting on AI in drug development

A debut fund despite a difficult market

While large venture firms continue to raise capital, emerging managers are facing one of the toughest fundraising environments in years. Even so, Sahir Ruof, previously a principal at SignalFire and head of business development at two healthcare startups, raised $27.5 million for his first independent fund, Proximal Ventures. The fund's bet is that AI can transform the tools, infrastructure and services that surround drug development.

Why the bet is on services, not software

Pharmaceutical companies have historically outsourced individual stages of drug development: synthesizing thousands of molecular compounds, organizing scalable manufacturing, and analyzing clinical trial data. 'For a long time it was believed that pharma is not a great buyer of software, but a very good buyer of services,' Ruof said. In his view, AI can automate a significant portion of this work, and startups will have a chance to capture billions of dollars of pharmaceutical spending by offering the same services cheaper and faster. He notes that the most valuable AI applications so far have been in service industries such as law and finance, and he sees similar opportunities in pharmaceutical services.

Portfolio and backers

Proximal invests at the pre-seed and seed stages with checks ranging from $500,000 to $1.5 million and has already backed six startups. Among them is ChronicleBio, co-founded by former OpenAI executive Fidji Simo; the company uses AI to analyze biological and medical data in order to better understand chronic diseases and find potential treatments. Ruof's own background is tied to the industry: before his two years at SignalFire, he led business development at Iterative Health (a startup focused on recruiting clinical trial participants) and oversaw partnerships at Flatiron Health, an oncology data company acquired by Roche in 2018 for $1.9 billion.

Why investors believed

Among the fund's backers are the venture firms SignalFire and Kleiner Perkins, Bertelsmann Healthcare Investments, as well as private investors, including the co-founders of Dimension Capital , Nana Lee and Zavain Dar. An investor is also Amy Abernethy, co-founder of Highlander Health and former principal deputy commissioner of the FDA, who met Ruof at Flatiron Health, where she served as chief medical officer. According to her, his ability to build relationships and identify industry bottlenecks made a strong impression on her, and it was precisely these qualities that helped Proximal invest in startups alongside larger and better-known funds. Ruof himself attributes the limited partners' trust to his sales experience, understanding of the healthcare ecosystem and connections: 'If you are building a company that sells into life sciences, one of the hardest things is getting the initial commercial flywheel going.'