Formal dissent in CHMP opinions on new medicines, 2020-2025

Disagreement within medicines regulation is rarely visible in the public record at the point an opinion is adopted. We examined divergent positions formally appended to opinions of the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) on new medicines from 2020 through 2025, both those opposing a positive opinion and those favoring authorization despite a negative opinion, describing how often they occurred, how large the dissenting minorities were, and which issues they raised. Divergent positions opposed 28 of 331 positive opinions (8.5%) and most often concerned efficacy and methodological limitations. Of 22 final negative opinions publicly available, 6 (27%) were accompanied by a divergent position favoring authorization. These records show when CHMP members disagreed about whether the evidence justified authorization. Indexing these disagreements and publishing vote outcomes with each opinion would make regulatory uncertainty visible and help clinicians, payers and health technology assessment bodies make better-informed decisions about treatment use and coverage.