This is a multicenter, randomized, double-blind, placebo-controlled Phase 3 study to compare
the progression free survival of participants with 131 I -refractory DTC and radiographic
evidence of disease progression within the prior 12 months, treated with lenvatinib 24 mg by
continuous once daily oral dosing versus placebo. The study is conducted in 3 phases: a
Prerandomization Phase (screening and baseline period), a Randomization Phase (double-blind
treatment period), and an Extension Phase (Optional Open Label (OOL) Lenvatinib Treatment
Period and a follow-up period).