Patients are usually considered for directed therapy (radiotherapy and/or surgery and/or thermo-ablation) in case of symptomatic lesions or at high risk of local complications. They also usually receive systemic bone-directed agents (bisphosphonate or denosumab), despite sparse available data in the context of differentiated thyroid carcinomas (DTC). As bone-directed agents have no antitumor activity, patients may require additional treatments. To date, only sorafenib and lenvatinib have been approved in the treatment of advanced Radioiodine Refractory Differentiated Thyroid Carcinomas (RR-DTC).~Lenvatinib demonstrated efficacy in RR-DTC compared to placebo. While other kinase inhibitors appeared to be less effective in controlling bone metastatic disease compared to other soft tissue sites, lenvatinib showed, in a small number of patients, significant decrease in bone tumors size.~Even if both study drugs are indicated in the treatment of patients suffering from RR-DTC with bone metastases, it is of essential importance to confirm that lenvatinib can provide clinical benefit and antitumor activity when combined with denosumab in this population.
This study evaluates the combination of lenvatinib with denosumab in bone-predominant metastatic Radioiodine Refractory Differentiated Thyroid Carcinomas. All patients will receive this combination of treatments.