Sorafenib: a review of its use in patients with radioactive iodine-refractory, metastatic differentiated thyroid carcinoma.

Sorafenib (Nexavar®) is the first tyrosine kinase inhibitor to be approved for the treatment of radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC). In the pivotal phase III DECISION trial in patients with RAI-refractory, locally advanced or metastatic DTC, oral sorafenib 400 mg twice daily significantly prolonged median progression-free survival (PFS) relative to placebo. The PFS benefit of sorafenib over placebo was evident in all pre-specified clinical and genetic biomarker subgroups, and neither BRAF nor RAS mutation status was predictive of sorafenib benefit for PFS. The objective response rate was significantly higher in patients receiving sorafenib than in those receiving placebo; all objective responses were partial responses. The overall survival benefit of sorafenib is as yet unclear, with no significant benefit observed at the time of primary analysis or at 9 months following the primary analysis. Overall survival was possibly confounded by the crossover of patients in the placebo group to sorafenib upon disease progression. The adverse events associated with sorafenib in the DECISION trial were consistent with the known tolerability profile of the drug, with hand-foot skin reaction, diarrhea, and alopecia reported most commonly. Most treatment-emergent adverse events were grade 1 or 2 in severity and occurred early in treatment. However, a high proportion of patients discontinued sorafenib therapy or required dose reductions or interruptions because of toxicity. Although final overall survival data are awaited, current evidence suggests that sorafenib is a promising new treatment option for patients with RAI-refractory, metastatic DTC.