Paper
Black-box trials are the registry pages that still tell the public remarkably little. The sponsor ranking changes once that stricter definition is centered.
Which named sponsors dominate the CT.gov black-box subset where older studies have no results, no linked paper, and no detailed description? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot. Using the wave-nine sponsor watchlist, we ranked named sponsors by black-box stock and black-box rate, then compared that table with no-results and ghost counts. Boehringer Ingelheim carried the largest named black-box stock at 755 studies, followed by GlaxoSmithKline at 579 and Pfizer at 539. Bayer was the sharper large-sponsor outlier on rate at 48.1 percent, while several top black-box repeaters were industry portfolios with hundreds of missing-results studies. The named black-box table therefore makes the industry deep-silence problem much more visible than the broader sponsor stock tables do, especially across major drug-company portfolios overall. Black-box status is a registry-page visibility definition and should not be read as proof that a sponsor produced no documentation or dissemination outside linked CT.gov fields.