Lenvatinib treatment in the real clinical practice of progressive, radioiodine-refractory differentiated thyroid carcinoma: analysis of a big series followed in a single center

Objectives: Endpoint of this study was to evaluate the efficacy and safety of Lenvatinib in a big series of patients (pts) followed in a single center and compare them with the SELECT-study. Methods: Epidemiological, clinical and pathological data were collected in a prospective database. Results: 60 pts started Lenvatinib: 27(45%) pts started Lenvatinib as compassionate use; 33(55%) pts started Lenvatinib after the commercialization in Italy. Differently to the SELECT-study our population showed a lower percentage of Hürthle-cell cancer and a higher percentage of PDTC (p=0.02). Eight (13.3%) pts never performed the first radiological control due to rapid death. The objective response rate (ORR), obtained after 3 months of therapy, was significantly lower than that of SELECT-study (31.7% vs 64.8%, p<0.001) but the best median tumor shrinkage of responders was similar (-43% vs -51.9%). The disease control and clinical benefit rates were obtained in 51/60(85%) pts vs 229/261(87.7%) pts (p=0.57) and 42/60 (70%) pts vs 209/261 (80.1%) pts (p=0.09), respectively. After a mean of 13 months of follow-up, 27/60 (45%) pts were still being treated: 4/27(15%) pts remained in partial-response; 20/27(74%) pts remained in stable-disease, 3/27(11%) had a progressive-disease. The median progression-free survival (PFS) and overall survival were 26 months and 15 months, respectively. Adverse events (AE) occurred in all pts. Our pts had a higher rate of fatigue (77% vs 59%), nausea and anorexia (70% vs 41%), weight loss (65% vs 46.4%), dysgeusia (44% vs 16.9%), and a lower rate of diarrhea (42% vs 59.4%) than pts of SELECTstudy (P=0.01, p=0.0001, p=0.0059, p=0.001 and p=0.01, respectively). The incidence of arterial hypertension and proteinuria were similar. Conclusions: Also in the clinical practice, Lenvatinib is effective and associated with a PFS longer than that of SELECT-study. In our group the ORR was lower but associated with a similar disease control and clinical benefit rates. All patients experienced AE but with a different prevalence respect to SELECT.