Senators Bill Cassidy and Elizabeth Warren introduced bipartisan legislation Monday requiring drug sponsors to disclose when artificial intelligence designs trial protocols or screens participant eligibility. The Clinical AI Transparency Act mandates registration of models in a National Institutes of Health public database before trials receive federal funding or Food and Drug Administration fast-track designation.

Sponsors cited three halted Phase II studies in 2025 and early 2026 where undisclosed algorithmic exclusion criteria reduced enrollment of elderly and rural participants below FDA diversity expectations. NIH director Monica Bertagnolli endorsed disclosure goals while asking for phased implementation so small biotech firms can comply without delaying lifesaving research.

Bill Requirements

Sponsors must publish model purpose, training data sources, and known failure modes in plain language summaries accessible to trial participants. Institutional review boards would confirm participants received notice before consent. FDA reviewers could pause trials lacking registration within 30 days of algorithm deployment.

The bill does not ban AI in trial design. It standardizes documentation similar to clinicaltrials.gov registration for study protocols. Warren said patients deserve to know when software rather than physician judgment excluded them from experimental therapies.

Industry Reaction

Biotechnology Innovation Organization lobbyists support transparency but requested protection for trade secrets in model weights. Cassidy amended draft text to allow redacted public summaries with full disclosure to FDA and NIH reviewers under confidentiality agreements.

Academic medical centers said they already document algorithmic tools in grant applications but welcome uniform federal format. Contract research organizations predicted modest compliance costs offset by reduced litigation from participants claiming undisclosed exclusion.

Regulatory Context

FDA issued voluntary guidance in 2024 on digital health tools in trials but did not mandate AI-specific registration. Commissioner Robert Califf testified in May that Congress must act where agency authority stops at post-market surveillance. The new bill fills pre-market gaps without expanding FDA appropriations, relying on existing user fees for enforcement staff.

Political Prospects

Leadership aides called the bill a candidate for attachment to must-pass FDA reauthorization later this year. Progressive and pro-industry groups rarely align on drug pricing but share interest in trial transparency after publicized failures in Alzheimer's and obesity studies using opaque screening tools.

Patient advocates planned testimony for a Health, Education, Labor, and Pensions subcommittee hearing July 16. Investors said disclosure rules may slow trial starts slightly but reduce rejection risk at FDA advisory committees questioning demographic balance.