Anlotinib in Locally Advanced or Metastatic Radioiodine-Refractory Differentiated Thyroid Carcinoma: A Randomized, Double-Blind, Multicenter Phase II Trial

Purpose: Alhough antiangiogenic agents are the bedrock of treatment for radioiodine-refractory differentiated thyroid carcinoma (RAIR-DTC), novel antiangiogenic agents with optimized features like greater target-binding affinities and more favorable pharmacokinetics profile are needed. This phase II randomized, double-blind, placebo-controlled trial investigated the efficacy and safety of anlotinib, a multikinase inhibitor, for RAIR-DTC. Patients and Methods: Patients (ages between 18 and 70 years) with pathologically confirmed locally advanced or metastatic RAIR-DTC were enrolled and randomly received 12 mg anlotinib once daily or placebo on day 1 to 14 every 3 weeks. Patients on placebo were allowed to receive open-label anlotinib after disease progression. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS) and safety. Results: Between September 2015 and August 2018, 76 and 37 patients randomly received anlotinib and placebo, respectively. Patients receiving anlotinib had a significantly longer median PFS [40.5 months, 95% confidence interval (CI), 28.3-not estimable (NE) versus placebo 8.4 months, 95% CI, 5.6-13.8; HR = 0.21, 95% CI, 0.12-0.37, P < 0.001], meeting the primary endpoint. OS was still immature, with a trend of benefit with anlotinib (HR = 0.57, 95% CI, 0.29-1.12). All patients in the anlotinib group experienced adverse events (AE); 8 (10.5%) discontinued treatment due to AEs. Conclusions: Anlotinib demonstrated promising efficacy and favorable tolerance in the treatment of locally advanced or metastatic RAIR-DTC, supporting further research to establish its role in the treatment of this serious disease.