The US Food and Drug Administration (FDA) has accepted Exelixis' New Drug Application (NDA) filing for cabozantinib for the  treatment of patients with progressive, unresectable, locally advanced, or metastatic medullary thyroid cancer (MTC). The FDA also granted priority review designation to the NDA for cabozantinib.

The Prescription Drug User Fee Act (PDUFA) action date is November 29, 2012. Priority Review is granted to a pharmaceutical product that, if approved, would meet an unmet medical need for a serious and life-threatening condition.

Cabozantinib is a potent inhibitor of MET, VEGFR2 and RET. RET is a receptor tyrosine kinase that is frequently activated by point mutation in medullary thyroid carcinomas. The therapeutic role of cabozantinib is currently being investigated across several tumor types. MET is upregulated in many tumor types, thus facilitating tumor cell escape by promoting the formation of more aggressive phenotypes, resulting in metastasis. MET-driven metastasis may be further stimulated by hypoxic conditions in the tumor environment, which are often exacerbated by selective VEGF-pathway inhibitors. In preclinical studies, cabozantinib has shown powerful tumoricidal, antimetastatic and antiangiogenic effects, including: extensive apoptosis of malignant cells, decreased tumour invasiveness and metastasis, decreased tumour and endothelial cell proliferation, blockade of metastatic bone lesion progression and disruption of tumour vasculature.

Exelixis, Inc. is a biotechnology company committed to developing small molecule therapies for the treatment of cancer. Exelixis is focusing its proprietary resources and development efforts exclusively on cabozantinib (XL184), its most advanced product candidate, in order to maximize the therapeutic and commercial potential of this compound.