Endocrine Abstracts

Introduction: Lenvatinib is an oral tyrosine kinase inhibitor (TKI) used for treatment of progressive, clinically significant or symptomatic disease in patients with iodine-refractory differentiated thyroid cancer (DTC).

Objective: To describe our clinical experience with lenvatinib in patients with iodine-refractory differentiated thyroid cancer.

Methods: Restrospective cohort study of patients with iodine-refractory differentiated thyroid cancer who received Lenvatinib as a first-line or second-line treatment from 2015 to 2018 in Hospital Universitario La Princesa. Patients with at least one radiographic control after the start of treatment with Lenvatinib were included. Baseline clinical characteristics, response rate to treatment and adverse effects (AE) were collected. Data analysis was carried out with descriptive statistics (G-Stat 2.0.1).

Results: Six patients were included with a mean age at diagnosis of 67(DS 11.2) years (two men/four women). Histologic diagnosis was: papillary thyroid cancer (4) and poorly differenciated folicular thyroid cancer (2). Distant metastasis were present at diagnosis in 2 patients or were delevoped at a median time of 36(IQR18) months in 4 patients, mainly lung metastasis. Lenvatinib was started after 6(IQR36) months from diagnosis of advanced disease (first-line treatment in 4 cases). First radiographic control (3 months after the start of lenvatinib) showed complete response (CR) in 1 case, partial response (PR) in 3 cases, 1 stable disease (SD) case and 1 progressive disease (PD) case with an objective response rate of 83.34%. All 3 cases with a second radiographic control at 8(IQR3) months showed stable disease. Initial Lenvatinib dose was 24 mg per day. Progressive dose reduction was needed in 83.33% of cases due to intolerability (20 mg in three cases, 14 and 10 mg in the remaining two cases respectively). AE (all grades) ocurred in 100% of cases. The most frequent were hyporexia (83.33%, grade 2 in 4 patients) asthenia (66.67%, grade 3 in three patients) and mucositis (50%, grade 3 in 2 patients). Other AE were weight loss (50%), diarrhea (50%), nausea (33.33%), hypertension (33.33%) and 1 case of hepatotoxicity. Oral nutritional supplements were needed in 83.3% of patients. Three patients required definitive withdrawal of Lenvatinib due to progression (1 patient) and severe toxicity (2 patients). Median time of follow-up with Lenvatinib was 12(IQR19) months with two cases of death due to cancer progression.

Conclusion: Our clinical experience shows lenvatinib as a useful treatment for iodine-refractory progressive DCT. AE are frequent needing closely management and dose adjustment.