PARP1 and Ewing sarcoma: Likewise, a Phase II randomised trial of the PARP inhibitor talazoparib with liposomal irinotecan vs temozolomide with liposomal irinotecan is currently being undertaken in relapsed/refractory ES patients [NCT04901702], whilst a single arm Phase II study of trabectidine with low dose irinotecan appears promising [NCT04067115] (61).