The Efficacy and Safety of Anlotinib in Neoadjuvant Treatment of Locally Advanced Thyroid Cancer: A Single-Arm Phase II Clinical Trial

Background: Surgery is the primary treatment for locally advanced thyroid cancer. For some cases, R0/R1 resection could not be achieved at initial diagnosis and neoadjuvant treatment would be an option. Anlotinib is a multitarget tyrosine kinase inhibitor, which demonstrated antitumor activity in radioiodine-refractory differentiated thyroid cancer and medullary thyroid cancer. We aimed to evaluate the efficacy and safety of anlotinib in locally advanced thyroid cancer in the neoadjuvant setting. Methods: This single-arm phase II study investigated the efficacy and safety of anlotinib (12 mg orally daily, 2 weeks on/1 week off) for 2-6 cycles in patients with locally advanced thyroid cancer in the neoadjuvant setting. The key eligibility criteria included age 14-80 years old; locally advanced thyroid cancer that would benefit from surgery, and at least one measurable lesion. Operable patients received surgery after neoadjuvant treatment. The primary endpoint was objective response rate (ORR). Results: A total of 13 patients were enrolled and received an average of 3.5 cycles of anlotinib treatment. The ORR of anlotinib was 76.9% (95% confidence interval: 46.2-95.0%). The R0/R1 resection rate in the intent-to-treat population was 61.5% and in the per-protocol population was 72.7%. The median time to response was 61.5 days, and the disease control rate at 18 weeks was 92.3%. No patients had blood transfusion or tracheotomy. Most adverse events (AEs) were grade 1 or 2 and tended to discontinue when neoadjuvant treatment ceased. Common AEs of all grades were hypertension (76.9%), hypertriglyceridemia (69.2%), proteinuria (53.8%), thyrotropin increase (53.8%), cholesterol elevation (53.8%), and hand-foot syndrome (38.5%). Conclusions: Anlotinib demonstrated antitumor activity in the neoadjuvant treatment and the majority of patients achieved R0/R1 resection. AEs were consistent with the known anlotinib AE profile. These results suggest that anlotinib neoadjuvant treatment represents a new option for locally advanced thyroid cancer. Clinical Trial Registration Number: NCT04309136.