Paper
Primary-only gaps are narrower than general endpoint-text gaps because they require the larger study narrative to remain present.
Which named sponsors most often leave older CT.gov study pages without the primary outcome description while keeping the broader detailed-description field? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot and ranked sponsors with at least 100 studies. We defined a primary-only gap as missing primary outcome description with detailed description still present, then compared stock, rate, and class patterns. AP-HP led the sponsor primary-only-gap stock table at 421 studies, followed by the National Cancer Institute at 402, NIAID at 351, and Sanofi at 299. Ranbaxy Laboratories Limited had the highest large-sponsor primary-only-gap rate at 98.0 percent, while Dr. Reddys Laboratories reached 82.9 percent and Alliance Oncology reached 60.5 percent. This endpoint-only gap removes the sentence naming the main outcome even when the broader study narrative remains visible for readers. These counts describe missing registry text fields and do not by themselves establish legal non-compliance, concealment, or absent materials elsewhere.