The archive · Health & Care · Product decision · 2024–2025
Delfa bets voice AI agents fix trial enrollment; $3.8M seed, 50+ trials
EF-co-founded London startup automates patient recruitment with voice AI agents; live across 50+ trials by Aug 2025 after $3.8M Air Street seed.
Delfa
What the business is
Delfa runs AI voice agents that prescreen, answer questions, book visits and enroll patients for clinical trial sites by phone, SMS or chat in any language, writing results into a site's CRM or CTMS; by August 2025 it was live across 50+ trials, mostly with US sites.
Starting capital：$3.8M seed led by Air Street Capital with Saras Capital, announced 2025-08-25.
How it started
Tom Farrand (CEO) and Gustav Bredell (CTO) went through Entrepreneurs First as prospective founders in September 2024; Farrand kept returning to Bredell's observation that PhD-level colleagues spent their days cold-calling people to fill trials. After roughly 300 conversations with contract research organizations, they founded Delfa in 2025 on the thesis that voice AI had finally crossed the quality threshold needed to automate outreach.
What happened
Delfa's agents prescreen for medical eligibility, answer questions, collect histories and book visits in any language, with every interaction logged, scored against 20+ QA metrics and audited by physicians. By August 2025 it was live across 50+ trials with site networks Flourish, Elevate and Re:Cognition; Elevate reported hitting 125% of a migraine study's target while saving thousands of recruiter hours, and Delfa was in talks to pilot with two of the top 20 global pharma companies. In August 2025 it raised a $3.8M seed led by Air Street Capital to build an AI-native CRM and deeper clinical-operations integrations.
No ending yet — it is still running.
Background
Delfa is a London startup founded in 2025 by Tom Farrand, who had built and deployed applied AI across J&J, Medtronic and Exscientia, and Gustav Bredell, a PhD from ETH Zürich who worked on early foundation models at Roche. The pair met going through Entrepreneurs First as prospective founders in September 2024 and started Delfa to automate clinical-trial patient recruitment with AI voice agents.
The founding insight was operational: more than a third of clinical-trial cost and delay comes from finding, qualifying and enrolling patients, yet the work is still done with Excel trackers, cold-call lists and phone tag at thousands of isolated trial sites. After speaking with about 300 contract research organizations, the founders bet that voice AI had crossed the quality threshold to take over that funnel — prescreening by phone, SMS or chat in any language, with physicians auditing outputs and every call logged against 20+ QA metrics.
By August 2025 Delfa was live across 50+ trials with site networks Flourish, Elevate and Re:Cognition, mostly for US customers. Elevate Medical Research reported hitting 125% of a migraine study's enrollment target and saving thousands of recruiter hours; in a vaccine trial the agent matched human conversion rates. The same month Delfa raised a $3.8M seed led by Air Street Capital to build an AI-native CRM and deeper trial-operations integrations, with pilots with two of the top 20 pharma companies in discussion.
The ambition is to climb from patient recruitment to an AI-native operating system for clinical trials — smarter site selection, automated study start-up and patient retention — turning the data its agents collect into a system of record that CRM leaders and trial software like Medidata or Veeva don't currently cover.
What has to be true
- Enrollment is a third of trial cost and delay yet runs on spreadsheets and cold calls — a manual bottleneck too painful to ignore and too repetitive for humans to do well.
- Voice AI crossed a quality threshold: agents handle eligibility nuance in any language while every interaction stays logged, scored and physician-audited for compliance.
- Customers feel the win immediately — Elevate hit 125% of a migraine study's target and saved thousands of recruiter hours, beating a competing AI startup head-to-head.
- The first-contact funnel produces the data for the next product, an AI-native CRM and trial-operations OS, making each conversation an asset rather than a cost.
What can be applied
Attack the most broken bottleneck in a regulated market: automate first contact with voice agents, prove ROI in hours saved, then turn every logged interaction into the system of record.
Aftermath
As of 2026-09-02 Delfa remains live and early-stage: the sources reviewed show no later public round or exit beyond the August 2025 seed, earmarked for the CRM, clinical-operations integrations and engineering hires. Its ambition is to move from recruitment to an AI-native operating system spanning site selection, study start-up and patient retention, selling directly to pharma. Watch items: proving voice agents hold up across indications and regulatory jurisdictions, and turning site-network wins into the system of record Salesforce, HubSpot, Medidata and Veeva don't cover.
Sources
- The Startup Speeding Up Clinical Trials With Voice AI
- Our investment in Delfa to fix clinical trials
- Founded & Funded: 2025-Q3 Portfolio News
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