LEOPARD project first identified from the literature a set of variables with potential predictive value to serve as the foundation for training advanced 2nd-generation AI-based predictive models. These include both routinely collected data from national OSO systems and a set of additional, clinically relevant variables selected by expert clinicians. Two tailored datasets were created: one for patients with DC and other end-stage liver diseases, and another for patients with HCC in order to obtain clinical predictors relevant to each patient population.
On this ground, the LEOPARD Training and Validation Cohort Study (TVDCS) was officially launched in February 2025.A major milestone (MS 2) was achieved in the Training and Validation Data Collection Study (TVDCS – NCT06675604) by June 2026, with 54 clinical sites open to recruitment and 1,000 patients enrolled across the seven participating European countries. In parallel, substantial efforts have been dedicated to ensuring the completeness, and overall quality of the collected data, enabling the start of the first interim statistical analysis. Preliminary results identified at baseline several innovating predictors of mortality/drop out with high predictive value offering the potential of a robust foundation for the development of the second-generation LEOPARD predictive models with improved patients’ stratification.
Significant progress was also made in defining and implementing the processes required to incorporate new predictive variables into the OSOs' software platforms (Milestone 4).
Regarding the second clinical LEOPARD study, PVC1 (NCT06723275), regulatory approval was obtained in France on September 2025, and three clinical sites are currently open for patient recruitment. For the remaining French centers, site initiation is currently underway. Outside France, the first regulatory approval was obtained for the national coordinating center in Italy in mid-June. In parallel, regulatory submissions and site agreement negotiations have progressed substantially in the remaining participating countries, with all participating centers expected to be open for recruitment by January 2027. In addition, the final version of the eCRF has been validated and is fully operational. First enrolments in PVC1 are expected early July 2026.
Another major milestone was the initiation of HCC imaging data transfer to establish the LEOPARD Imaging Repository for radiomic analyses. The first imaging datasets have been successfully uploaded within the framework of the LEOPARD TVDCS study, and the repository is now fully operational and ready to receive imaging data from the LEOPARD PVC1 study. The implementation of this repository required an extensive regulatory approval process and full GDPR compliance, a process currently achieved.
Overall, collaboration among clinicians, AI researchers, data scientists, and patient organizations continues to be a key driver of the LEOPARD project. The project has successfully transitioned from the setup phase to the technical implementation and development phase, marking an important step towards the development and validation of second and next-generation predictive algorithms in liver transplant candidates.
