[Lenvatinib in radioiodine refractory thyroid carcinomas]

Differentiated thyroid cancers are usually cured by an appropriate surgery and a radioiodine remnant ablation. If metastases occur, successive radioiodine administrations and/or local treatments can be provided. Nevertheless, some patients will be, or become refractory to radioiodine. In case of significant and rapid progression of metastatic lesions, they will be candidate to kinase inhibitor treatments. Two agents are now approved in this situation: sorafenib and lenvatinib. Lenvatinib (Lenvima^®) is a tyrosine kinase inhibitor (TKI) targeting the VEGFR1-3, FGFR 1-4, PDGFR-α, RET and c-kit. It received an FDA and EMA approval in February and March 2015 for the treatment of radioiodine refractory thyroid cancers following the SELECT study's results. In this study, patients treated with lenvatinib had a significant increase in progression-free survival (18.3 months vs. 3.6 months; HR=0.21; CI=0.14-0.31, P < 0.001) and response rate (64.8% vs. 1.5% with placebo). The median overall survival was not reached in both groups at the time of data cutoff. In France, lenvatinib was first available within a compassionate use program (ATU) and is now dispended by hospitals because not yet marketed.