Pediatric liver cancers (PLC) are rare tumors. In particular, hepatoblastomas are usually treated with cisplatin-based neoadjuvant chemotherapy followed by surgical removal of the tumor and adjuvant chemotherapy. However, some hepatoblastomas develop resistance to chemotherapy during the initial neoadjuvant chemotherapy or after tumor recurrence, and the molecular determinants of cisplatin resistance are yet to be discovered. In contrast to hepatoblastomas, pediatric HCCs respond poorly to chemotherapy, and as in adults, they have a poor prognosis if not completely removed by surgery. There is thus an urgent need for new therapeutic strategies to overcome this resistance. Now the inventors demonstrate that Elimusertib and
Cisplatin combination shows synergistic efficacy on tumor cell viability inhibition in pediatric liver cancer cell lines. The present invention thus relates to the combination of cisplatin and Elimusertib for the treatment of pediatric liver cancers.