Phase II clinical trial of axitinib in metastatic pheochromocytomas and paraganlgiomas (P/PG): Preliminary results.

457 Background: Malignant pheochromocytoma/paraganglioma (P/PG) is a rare malignancy. Management of metastatic disease includes surgery, external radiation, 131I-MIBG and systemic chemotherapy. CVD (cyclophosphamide, vincristine and dacarbazine) is the only chemotherapy commonly used to treat metastatic disease. Putative anti-angiogenic agents such as the tyrosine kinase inhibitor (TKI) axitinib target a well-recognized pathway thought to be active in many tumors. Methods: Patients with histologically confirmed P/PG previously treated or naive to treatment received axitinib at initial dose of 5 mg BID. Primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival, response rate and safety. Results: Between January and September 2014 nine patients have been enrolled. The median age was 54.7 years, (range 42.5 – 70.5); median number of previous systemic treatments was one (range 0 – 3). Three of the nine patients achieved a partial response. An additional 5 patients have ha...