Multi-Agent System for Clinical Trial Enrollment: 40% Faster Enrollment with Llama 4, Qwen 3.8 Max, and a Compliance Agent on AWS Bedrock

By Sam Qikaka

Category: Agents & Architecture

A vendor-neutral guide to a three-agent architecture on AWS Bedrock for clinical trial patient recruitment, using Llama 4 for eligibility extraction, Qwen 3.8 Max for site matching, and a fine-tuned compliance agent for IRB documentation. Based on a pilot with a mid-size CRO, the system reduced enrollment time by 40% and cost-per-enrolled-patient by 28%.

Multi-Agent AI for Accelerated Clinical Trial Enrollment on AWS Bedrock As of May 23, 2026, pharmaceutical companies are increasingly turning to multi-agent AI systems to accelerate clinical trial enrollment—a process that remains one of the most expensive and time-consuming bottlenecks in drug development. This vendor-neutral guide presents a practical architecture using three specialized agents deployed on AWS Bedrock: Llama 4 for patient eligibility extraction, Qwen 3.8 Max for site matching, and a fine-tuned compliance agent for IRB documentation. Based on a pilot with a mid-size Contract Research Organization (CRO), the system reduced enrollment time by 40% and cost-per-enrolled-patient by 28% . We cover agent handoff patterns, deployment steps on AWS Bedrock AgentCore, cost benchmarks, and key lessons for pharma operations. Why Multi-Agent Systems for Clinical Trial Enrollment? Cli

nical trial enrollment faces persistent challenges: only 3–5% of eligible patients actually enroll, and the average time from site activation to first patient enrolled can exceed 7 months . Manual chart review, site feasibility assessment, and regulatory documentation are labor-intensive and error-prone. Traditional single-model AI approaches struggle with the diverse tasks required—extracting medical data from unstructured records, matching patients to suitable trial sites, and generating compliant IRB forms. Multi-agent systems solve this by breaking the workflow into specialized subtasks, each handled by a dedicated model optimized for its domain. The result is not only faster processing but also improved accuracy per step, reduced human error, and a clear audit trail for regulators. As healthcare AI regulation matures, decomposing sensitive decisions across multiple agents with separ

ate oversight becomes a compliance advantage. Architecture Overview: Three Agents on AWS Bedrock Our reference architecture uses three agents, each powered by a different LLM, orchestrated by AWS Bedrock AgentCore : - Agent 1: Patient Eligibility Extraction (Llama 4) Llama 4 (Meta’s latest family, released in April 2026) excels at medical NLP tasks—extracting diagnoses, medications, lab results, and eligibility criteria from patient records. We use the 70B parameter variant, fine-tuned on a corpus of de-identified clinical notes and trial protocols. Llama 4’s long‑context window (up to 1 million tokens) allows processing entire patient charts without chunking. The agent outputs a structured eligibility summary as JSON. - Agent 2: Site Matching (Qwen 3.8 Max) Qwen 3.8 Max (Alibaba Cloud, March 2026) offers strong multilingual and geographical reasoning capabilities, ideal for matching pat

ients to trial sites based on location, site capabilities, and recruitment history. Its 128K context window and built‑in geocoding functions enable real‑time site score calculations. The agent returns a ranked list of nearest appropriate sites with match confidence scores. - Agent 3: Compliance Agent (Fine‑tuned for IRB Documentation) This agent is a fine‑tuned version of a smaller LLM (e.g., Llama 3.1 8B) specifically trained on FDA and IRB forms, consent templates, and regulatory guidelines. Its output—draft consent forms, site feasibility reports, and regulatory checklists—is reviewed by a human compliance officer before submission. The agent enforces formatting rules and flags any ambiguous language. All three agents run as dedicated AgentCore projects within the same AWS account, sharing a common Amazon S3 bucket for intermediate data. Agent orchestration is handled by Bedrock Agent

Core’s built‑in state machine, which routes outputs between agents according to a handoff plan. Agent Handoff Patterns: How Data Flows Between Agents The workflow follows a sequential handoff pattern with error handling and human‑in‑the‑loop gates: 1. Patient chart ingestion triggers Agent 1 (Llama 4). The agent runs on Amazon Bedrock’s serverless inference and writes the eligibility summary to S3 under a specific prefix ( ). 2. AgentCore listens for the completion event and automatically triggers Agent 2 (Qwen 3.8 Max). The site matching agent reads the eligibility summary and the patient’s geolocation, queries a static site database (stored in DynamoDB), and produces a top‑3 site recommendation, also stored in S3. 3. A human‑in‑the‑loop step follows: a clinical coordinator reviews the matched site list through a simple web UI (provisioned via AWS App Runner). Only after approval does t

he flow proceed to Agent 3. 4. Agent 3 (Compliance) generates the draft IRB documentation based on the approved site and patient data. The output is written to a separate S3 bucket monitored by compliance staff for final review and signature. Error handling is built into the state machine: if an age