A single-arm, phase II, multicenter trial of sunitinib maleate (SU) in locally advanced or metastatic pheochromocytoma/paraganglioma (PC/PG): Interim results.

431 Background: Metastatic PC/PG is rare and may be sporadic or have a genetic basis. Treatment remains challenging in the absence of well-controlled randomized trials. Case reports suggest clinical activity of SU in this setting. We aim to prospectively evaluate radiological and biochemical response to SU, and assess its toxicity profile in PC/PG. Methods: This is an ongoing single-arm, phase II, multicenter, investigator-initiated clinical trial, enrolling patients (pts) with metastatic or unresectable locally advanced malignant PG or PC with ECOG PS 0-2, no previous treatment with tyrosine kinase inhibitors, and evidence of radiological progression or disease-related symptoms. All pts receive 50mg SU daily at standard dosing, following blood pressure stabilization, and are assessed for radiological and biochemical response (with urine metanephrines, catecholamines or serum chromogranin A) q12 weeks until disease progression, unacceptable toxicity or pts withdrawal. Futility was defined as no documented...