MIP-IB12B, the pivotal phase 2 study evaluating efficacy and safety of AZEDRA in patients with malignant relapsed/refractory PPGL, has completed its anticipated enrollment. The purpose of this sub-study, MIP-IB12B-EAP, is to provide expanded access to AZEDRA for newly enrolled subjects with iobenguane-avid metastatic and/or recurrent PPGL and to collect additional safety data.