Lenvatinib for the Treatment of Radioiodine-Refractory Thyroid Cancer in Real-Life Practice.

Background: In the Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) phase 3 trial on advanced radioactive iodine-refractory differentiated thyroid cancer (rDTC), lenvatinib improved median progression-free survival over placebo by almost 15 months and induces an objective response rate of 64.8%, but adverse events occurred in almost all patients. The present study evaluates the efficacy and toxicity of lenvatinib treatment in real-life practice. Methods: Clinical charts of 88 consecutive patients treated with lenvatinib from July 2015 to June 2016 in 27 French centers were retrospectively reviewed. Patients treated for other thyroid cancer types ( n  = 11) or previously treated with lenvatinib within a trial ( n  = 2) were excluded and the remaining 75 rDTC patients formed the basis of this report. Results: 75 rDTC patients were analyzed (33 females, median age 65 years [range, 35-88 years]), 12 had an Eastern Cooperative Oncology Group performance status ≥2; 24 cases received lenvatinib as first line systemic treatment; 47 (63%) patients had documented progressive disease prior to treatment initiation. Distant metastases were located in lungs, bones, and lymph nodes (89%, 60%, and 69%, respectively). The initial treatment dose was 24 mg in 54 patients and was lower in the other 21 patients. The median follow-up was 7 months, with a median duration of treatment of 6 months [0.3-15]. Median progression-free survival was 10 months. Among the 65 patients with evaluation of tumor response during treatment, best tumor response was a partial response in 23 patients (31%) and stable disease in 38 (51%). Eleven patients (14.7%) discontinued lenvatinib because of disease progression. Forty-four (59%) and 23 (31%) patients had dose reductions or an interruption of lenvatinib for adverse events (AEs). The most frequent AEs related to treatment were fatigue, hypertension, weight loss, diarrhea, and anorexia. Eleven deaths occurred during the study (one considered to be drug related). Pneumothorax occurred in 2 patients with lung metastases. Conclusions: Real-life patients with rDTC can benefit from lenvatinib treatment. AEs are frequent and should be closely monitored.