PDGFRB and differentiated thyroid carcinoma: A newer TKI, lenvatinib, with similar targets to sorafenib (VEGFR, FGFR, PDGFR, RET, KIT) yielded a PFS of 18.3 months versus 3.6 months in the placebo arm in a phase III trial of patients with iodine-refractory, progressive differentiated thyroid cancers.43 Complete response was only 1.5%, but there was a higher partial response of 63% compared with 35% PR observed in vemurafenib.