Repeated Radionuclide therapy in metastatic paraganglioma leading to the highest reported cumulative activity of 131I-MIBG

A phase I clinical trial for [131I]meta-iodobenzylguanidine therapy in patients with refractory pheochromocytoma and paraganglioma

Refractory pheochromocytoma and paraganglioma (PPGL) have a poor prognosis and the treatment strategy remains to be established. This multi-institutional phase I study was performed to determine the safety, dose-limiting toxicity (DLT), and efficacy of [¹³¹I]-meta-iodobenzylguanidine (¹³¹I-mIBG) therapy for refractory PPGLs. Twenty patients with refractory PPGL were enrolled in this study. We administered fixed doses of ¹³¹I-mIBG to all patients, delivering a second and third course of ¹³¹I-mIBG to eight and three patients, respectively. During the 20 weeks after ¹³¹I-mIBG injection, the authors surveyed the adverse events in accordance with the Common Terminology Criteria for Adverse Events. All patients experienced adverse events and adverse reactions, but none experienced a grade 4 adverse event. Twelve weeks after ¹³¹I-mIBG injection, examinations for the evaluation of therapeutic effects was performed in accordance with the Response Evaluation Criteria in Solid Tumours (RECIST). The best overall response rates (based on RECIST categories) were 10% (complete response), 65% (stable disease), 15% (progressive disease), and 10% (not all evaluated). The efficacy and safety of ¹³¹I-mIBG therapy was shown in patients with refractory PPGL, and DLT was observed in neither single nor repeated ¹³¹I-mIBG therapy, indicating a tolerability for ¹³¹I-mIBG therapy.

The vial kit formulation for preparation of no-carrier-added 131 I-MIBG

We have developed a new set of lyophilized kits, composed of 3 different kits, for the instant preparation of no-carrier-added ¹³¹ I-MIBG in the clinic. We here discussed the formulation of the kits, optimization of radiolabelling, quality control of radiolabeled ¹³¹ I-MIBG, and studies of animal biodistribution. The no-carrier-added (nca) ¹³¹ I-MIBG injection could be prepared within 30 minutes in the clinic with the help of the lyophilized kits. The radiochemical purity and specific activity (SA) could achieve above 98% and 6700 MBq/mg, respectively.