https://www.selleckchem.com/products/GDC-0980-RG7422.html Lenvatinib has proven efficacy in progressive, radioiodine- (RAI-) refractory thyroid cancer (TC). Dose reductions are commonly performed due to decreased tolerability and adverse effects. This retrospective multicenter study analyzed overall survival (OS) and progression-free survival (PFS) and tolerability in the Austrian patient population treated with lenvatinib. Clinical data of 43 patients (25 males and 18 females) with a median age of 70 years (range 39-91 years) and RAI-refractory TC with metastases to the lymph nodes (74%), lungs (86%), bone (35%), liver (16%), and brain (12%) were analyzed. The mean duration of treatment with lenvatinib was 26.6 ± 15.4 months with dosage reductions required in 39 patients (91%). PFS after 24 months was 71% (95% CI 56-87), and overall survival (OS) was 74% (95% CI 60-88), respectively. OS was significantly shorter ( =0.048) in patients with a daily maintenance dosage ≤ 10 mg (63%) (95% CI 39-86) as compared to patients on ≥ 14 mg lenvatinib (82%) (95% CI 66-98) daily. Dose reduction was noted in 39 patients (91%). Grade ≥3 toxicities (hypertension, diarrhea, weight loss, and palmar-plantar erythrodysesthesia syndrome) were most common leading to discontinuation of lenvatinib in 7 patients (16%). Lenvatinib showed sustained clinical efficacy in patients with metastatic RAI-refractory TC even with reduced maintenance dosages over years. The effects were comparable to the registration trial, although patients had a higher median age and, more commonly, dose reductions. Lenvatinib showed sustained clinical efficacy in patients with metastatic RAI-refractory TC even with reduced maintenance dosages over years. The effects were comparable to the registration trial, although patients had a higher median age and, more commonly, dose reductions. Endocrine hormones are closely associated with homeostasis, so it is important to clarify hormone secretion dynamics in shock. Few r