On July 11, 2025, NuCana plc announced a change in its American Depositary Shares (ADS) ratio, reducing the ratio from 1 ADS to 25 ordinary shares to 1 ADS to 5,000 ordinary shares, effective August 8, 2025. This change is equivalent to a 1-for-200 reverse ADS split and will not affect ADS holders' proportional equity interests.