P14-F8

P14-F8 is a **humanized single-domain antibody nanobody** directed against the **receptor-binding domain of the SARS-CoV-2 spike protein**. It has been reported as a parental neutralizing binder used to construct the bispecific antibody SYZJ001 together with the fully human antibody R15-F7. Available literature indicates that P14-F8 binds a non-overlapping epitope on spike RBD and **blocks or sterically hinders interaction with the host ACE2 receptor**, thereby neutralizing viral entry. The program appears to have been associated with **Sanyou Biopharmaceuticals** and **ZJ Bio-Tech** in the broader anti-COVID-19 antibody effort, but publicly accessible evidence supports P14-F8 primarily as a research-stage component/parental antibody rather than a marketed standalone therapeutic.