Proximal Ventures closes $27.5 million debut fund for AI drug development start-ups

Proximal Ventures, an early-stage venture capital firm founded by former SignalFire investor Sahir Raoof, has closed its first fund at $27.5 million, above its original $25 million target. The close of Fund I was announced on Tuesday, 10 November 2026. The firm will back pre-seed and seed start-ups that use artificial intelligence to change how medicines are developed, from research tools and data infrastructure to the outsourced services that drug companies buy.

Proximal's bet is a practical one, aimed at the work around medicines rather than the molecules themselves. Its thesis, as set out in reports of the close, is that drug makers are more used to buying services than software, and that AI could automate a large part of the work they now hand to outside service providers. If that is right, small AI-first companies could win a share of the large sums the pharmaceutical industry spends on outsourced research, data and trial work.

The one named investment shows the kind of company the fund likes. ChronicleBio, based in Menlo Park, California, is building an AI-driven data platform to find biological subtypes within hard-to-treat chronic neuroimmune conditions such as POTS, long COVID and ME/CFS. Its co-founder is former OpenAI executive Fidji Simo, and its chief executive is Rohit Gupta. Splitting broad conditions into clearer subtypes is the sort of groundwork that can make clinical trials smaller and better targeted.

The list of backers also matters. A debut fund from a first-time manager usually depends on people who know the founder's track record. Here, Raoof's former firm SignalFire is a backer alongside Kleiner Perkins, while Bertelsmann Healthcare Investments, Domino Lane and PagsGroup are listed as strategic partners, so the fund mixes venture firms with corporate and strategic money. Raoof's ties to Amy Abernethy go back to Flatiron Health, where she was chief medical officer before her work at the US drug regulator.

For readers following the global start-up ecosystem, the fund is a sign of where early-stage health money is going: towards the plumbing of drug development rather than only new medicines. Founders anywhere who are building AI tools for trial operations, regulatory paperwork, lab data or research services sit inside the area such funds say they want to back, and small cheques at the pre-seed stage are often how young companies outside the US first reach American investors.

Peepals calculation: The fund closed $2.5 million, or 10%, above its target ($27.5 million against $25 million; 27.5 ÷ 25 = 1.10). One trade report says the fund plans to back about 20 start-ups; at cheques of $500,000 to $1.5 million, 20 first cheques would add up to between $10 million and $30 million (20 × 0.5 and 20 × 1.5), and the seven companies backed so far are 35% of that planned number (7 ÷ 20 = 0.35). Our calculation from the reported figures.

Short-term: Seven start-ups already have Proximal money, and the firm now has capital for further pre-seed and seed cheques in AI tools and services for drug development. More portfolio names are likely to become public as those companies announce their own rounds.

Long-term: If AI-run services take work now done by large outsourcing firms, the companies Proximal backs could become suppliers to big drug makers, and the fund's results will show whether specialist micro-funds can compete with larger generalist investors in health technology.

Who is affected: Early-stage founders building AI for drug research, trials and regulatory work; pharmaceutical companies and the service providers they buy from; patients with chronic conditions such as long COVID, whose research ChronicleBio targets; and the fund's backers.

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