Phase II clinical trial of sorafenib in metastatic medullary thyroid cancer.

PURPOSE: Mutations in the RET proto-oncogene and vascular endothelial growth factor receptor (VEGFR) activity are critical in the pathogenesis of medullary thyroid cancer (MTC). Sorafenib, a multikinase inhibitor targeting Ret and VEGFR, showed antitumor activity in preclinical studies of MTC. PATIENTS AND METHODS: In this phase II trial of sorafenib in patients with advanced MTC, the primary end point was objective response. Secondary end points included toxicity assessment and response correlation with tumor markers, functional imaging, and RET mutations. Using a two-stage design, 16 or 25 patients were to be enrolled onto arms A (hereditary) and B (sporadic). Patients received sorafenib 400 mg orally twice daily. RESULTS: Of 16 patients treated in arm B, one achieved partial response (PR; 6.3%; 95% CI, 0.2% to 30.2%), 14 had stable disease (SD; 87.5%; 95% CI, 61.7% to 99.5%), and one was nonevaluable. In a post hoc analysis of 10 arm B patients with progressive disease (PD) before study, one patient had PR of 21+ months, four patients had SD >or= 15 months, four patients had SD

Medullary thyroid cancer: targeting the RET kinase pathway with sorafenib/tipifarnib.

Medullary thyroid carcinoma (MTC) is an uncommon malignancy of hereditary and sporadic presentation. Mutations in the RET proto-oncogene are involved in the pathogenesis of familial MTC and >50% of the sporadic cases. Currently, there is no effective treatment for recurrent or metastatic MTC. We report here a rapid response to a sorafenib (RET and RAF kinase and vascular endothelial growth factor receptor inhibitor)--based regimen in a patient with sporadic MTC who had advanced, progressive disease and a novel RET kinase aberration at exon 11 shown in tumor tissue.