General Information - Additional Information (Detail) - Subsidiary |
6 Months Ended | ||
|---|---|---|---|
Aug. 11, 2025 |
Apr. 16, 2025 |
Jun. 30, 2025 |
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| Disclosure Of General Information About Financial Statements [Abstract] | |||
| Description of nature of entity's operations | clinical-stage biopharmaceutical company developing a portfolio of new medicines to treat patients with cancer | ||
| Name of reporting entity | NuCana plc | ||
| Domicile of entity | United Kingdom | ||
| Country of incorporation | England and Wales | ||
| Number of subsidiaries | 3 | ||
| Name of subsidiary | NuCana, Inc., NuCana Limited and NuCana BioMed Trustee Company Limited | ||
| Description of change In ratio of shares | one ADS representing 25 ordinary shares, to one ADS representing 5,000 ordinary shares. | from one ADS representing one ordinary share, to one ADS representing 25 ordinary shares. |