This is a study to evaluate the efficacy and safety of belzutifan monotherapy in participants
with advanced pheochromocytoma/paraganglioma (PPGL), pancreatic neuroendocrine tumor (pNET),
von Hippel-Lindau (VHL) Disease-Associated Tumors, Advanced Gastrointestinal Stromal Tumor
(wt GIST), or Advanced Solid Tumors With hypoxia inducible factor-2 alpha (HIF-2) related
genetic alterations. The primary objective of the study is to evaluate the objective response
rate (ORR) of belzutifan per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST
1.1) by blinded independent central review (BICR).

Difluoromethylornithine (DFMO) will be used in an open label, single agent, multicenter,
study for patients with neuroblastoma in remission. In this study subjects will receive 730
Days of oral difluoromethylornithine (DFMO) at a dose of 750 mg/m2 250 mg/m2 BID (strata 1,
2, 3, and 4) OR 2500 mg/m2 BID (stratum 1B) on each day of study. This study will focus on
the use of DFMO in high risk neuroblastoma patients that are in remission as a strategy to
prevent recurrence.