FDA grants Orphan Drug Designation to Plus Therapeutics’ REYOBIQ (rhenium Re186 obisbemeda) for pediatric malignant gliomas, including ependymoma, supporting development of targeted CNS radiotherapy.
Written By: A. Musharaf Mohammad, BPharm
Reviewed By: Pharmacally Editorial Team
FDA Grants Orphan Drug Designation for Pediatric Brain Tumors
The U.S. Food and Drug Administration has granted Orphan Drug Designation (ODD) to REYOBIQ (rhenium Re186 obisbemeda), an investigational targeted radiotherapeutic from Plus Therapeutics, for the treatment of pediatric malignant gliomas. The designation also broadly covers malignant glioma, including pediatric ependymoma, beyond the company’s original request.
High Unmet Need in Pediatric Malignant Gliomas
Pediatric malignant gliomas are rare, aggressive central nervous system tumors associated with limited treatment options and poor outcomes. Current standards of care, including surgery and radiation, frequently fail to prevent recurrence. Pediatric high-grade gliomas, including ependymoma, occur in approximately 3.3 cases per 100,000 individuals, with five-year survival rates reported as low as 22% depending on tumor characteristics and treatment extent.
REYOBIQ Designed for Targeted CNS Radiotherapy
REYOBIQ is an injectable radiotherapy designed to deliver high-dose radiation directly to CNS tumors while minimizing exposure to surrounding healthy tissue. The therapy uses rhenium-186, a radioisotope with beta energy for tumor cell destruction and gamma emission that enables real-time imaging. The product is being evaluated across multiple CNS malignancies, including recurrent glioblastoma, leptomeningeal metastases, and pediatric brain cancers in the ReSPECT-GBM, ReSPECT-LM, and ReSPECT-PBC clinical trials.
Company Highlights Potential Clinical Impact
Marc Hedrick, President and Chief Executive Officer of Plus Therapeutics, said the designation represents an important milestone and supports the company’s strategy of delivering targeted radiation directly to CNS tumors. He added that REYOBIQ’s ability to precisely deliver high-dose radiation while limiting exposure to healthy brain tissue could improve outcomes in this underserved pediatric population and broaden its applicability across multiple CNS tumor indications.
Builds on Ongoing Clinical and Regulatory Progress
The orphan designation builds on recent regulatory and clinical progress for REYOBIQ, including completion of a Type B meeting with the FDA supporting development in leptomeningeal metastases, encouraging data from the ReSPECT-LM trial, and ongoing Phase 1 and Phase 2 studies. The company has also received clearance of an Investigational New Drug application to evaluate REYOBIQ in pediatric patients with high-grade glioma and ependymoma.
About Orphan Drug Designation
Orphan Drug Designation is granted to therapies targeting rare diseases affecting fewer than 200,000 people in the United States. The designation provides incentives including potential seven years of market exclusivity following approval, tax credits for qualified clinical trial expenses, and exemptions from certain regulatory fees.
Reference
Plus Therapeutics Granted U.S. FDA Orphan Drug Designation to REYOBIQ™ in Pediatric Malignant Gliomas, 08 April 2026, https://ir.plustherapeutics.com/news-releases/news-release-details/plus-therapeutics-granted-us-fda-orphan-drug-designation
About the Writer
Sana Jamil Khan is a B.Pharm graduate with a strong interest in medical writing and scientific communication. Her work focuses on interpreting clinical research, exploring developments in pharmaceutical science, and presenting complex medical information in a clear and accessible manner. She is particularly interested in topics related to human clinical studies, drug safety observations, and emerging therapeutic research.