The Annual Clinical Trials Roundup 2026 Edition: The Perfect Storm

By Heidi Chen, Director, Research &, Commercial Services ; Shannon Fisher, Principal Analyst/Subject, Matter Expert, Citeline

Citeline’s annual Clinical Trials Roundup reveals that trial initiations in 2025 declined 16% versus 2024, reflecting a perfect storm of regulatory upheaval, funding contractions, geopolitical tensions, and sweeping government restructuring. Industry-sponsored trial starts posted a slightly more modest 13% drop.

Decreases were seen across all therapeutic areas, with the largest decreases in ophthalmology (down 28%) and cardiovascular (down 27%). These declines were likely driven by systemic or macro-level factors including the decrease of early-phase China activity and mature, low-differentiation late-phase drug programs.

Non-small cell lung cancer (NSCLC) and type 2 diabetes once again held the two top spots for trial initiations in 2025. Obesity rose in the ranks from sixth to third, driven largely by the success of the GLP-1 franchises and the development of oral and next-generation formulations. Hypertension fell from fourth to seventh, with overall trial initiations plunging 40% and Phase I activity decreasing 44% — the steepest Phase I decline among the top 10 diseases.