Activity and Safety of Sunitinib in Patients with Advanced Radioiodine Refractory Thyroid Carcinoma: A Retrospective Analysis of 57 Patients.

BACKGROUND: The aim of this study was to evaluate the effectiveness of sunitinib in patients with progressive radioiodine refractory (RAIR) thyroid cancer (TC).

MATERIALS AND METHODS: A multicentric retrospective analysis was performed of patients treated in six TUmeurs THYroïdiennes REFractaires participating centers. All patients with progressive RAIR TC who were treated with sunitinib outside a clinical trial between August 2007 and March 2015 were retrospectively and consecutively included. The primary endpoint was the overall response rate (ORR) and disease control rate ≥6 months based on RECIST criteria. Secondary endpoints included evaluation of overall survival (OS) and progression-free survival (PFS) from the first dose of sunitinib. Primary and secondary endpoints were also evaluated according to treatment setting: first or second line of tyrosine kinase inhibitor (TKI).

RESULTS: Fifty-seven patients (29 men; 50.8%), mean age 62.2 years (range 43-80 years) with progressive RAIR TC were included. Sunitinib was the first-line TKI treatment for 32 (56.1%) patients and the second-line TKI treatment for 25 (43.9%) patients. For all patients, according to RECIST criteria, ORR was 35.1% (20 patients) and disease control rate ≥6 months was 68.4% (39 patients). No complete response was observed. Six (10.5%) patients showed disease progression. When sunitinib was used as first-line TKI therapy, ORR was 46.9% (15/32 patients), and disease control rate ≥6 months was 75% (24/32 patients). When sunitinib was used as second-line TKI therapy, ORR was 20% (5/25 patients), and disease control rate ≥6 months was 60% (15/25 patients). The median OS and PFS were 21.0 (range 15-29) and 10.2 months (range 6-13), respectively, for all patients. With sunitinib as first-line TKI-therapy, median OS and PFS was 30.0 (range 19.0-53.0) and 15 (range 7.0-21.0) months, respectively. As second-line therapy, median OS and PFS were 13 (range 8.0-20.0) and 6 (range 5.0-11.0) months, respectively. Eleven (19.3%) patients experienced grade 3 toxicity, and four patients (7.0%) experienced grade 4 toxicity.

CONCLUSION: The efficacy of sunitinib as first- and second-line TKI therapy in a large cohort of patients treated for progressive RAIR TC is herein reported. Further prospective studies are needed to evaluate the effectiveness of sunitinib in RAIR TC.