Multicenter retrospective study of real-world outcomes with lenvatinib for RAI-refractory differentiated thyroid cancer

Lenvatinib is an established first0line therapy for radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC) but real-world data are limited. A retrospective study at seven centers in Hong Kong evaluated lenvatinib for RAI-refractory DTC. Efficacy outcomes were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and disease control rate (DCR). Between January 2010 and April 2025, 82 patients were included. The median age at treatment initiation was 69 years, and the median starting dose of lenvatinib was 14 mg. Median follow-up was 24.7 months (IQR 14.2-46.6). Median PFS was 31.0 months (95% CI 16.6-40.8) and median OS was 46.8 months (33.6-67.6), with multivariable analyses identifying brain metastasis as the most consistent adverse prognostic factor. The ORR was 52.4% and the DCR was 82.9%. Treatment-related adverse events were common, most frequently hypertension (73.2%; grade ≥3: 45.1%) and proteinuria (57.3%). The authors conclude that lenvatinib achieved durable response in patients with RAI-refractory DTC despite the frequent use of reduced starting doses. Treatment-related toxicities were common, but generally manageable, allowing prolonged treatment in many patients.