Plus Therapeutics (NASDAQ:PSTV), a clinical-stage pharmaceutical company developing targeted radiotherapeutics for central nervous system (CNS) cancers, announced on April 8, 2026, that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to REYOBIQ™ (rhenium Re186 obisbemeda).
The designation is specifically for the treatment of pediatric malignant gliomas, with the scope recently broadened to include progressive pediatric ependymoma.
These are among the most difficult-to-treat and aggressive forms of brain cancer in children, with significant unmet medical needs.
The FDA’s Orphan Drug Designation program provides several critical incentives for companies developing treatments for rare diseases (those affecting fewer than 200,000 people in the U.S.).
For Plus Therapeutics, these benefits include a potential seven years of market exclusivity upon regulatory approval, federal tax credits for clinical trial expenses, and exemptions from certain FDA application fees.
In tandem with the designation, Plus Therapeutics highlighted that it has received FDA Investigational New Drug (IND) clearance to proceed with its pediatric high-grade glioma and ependymoma programs.
The company is currently conducting Phase 1/2 clinical trials to evaluate the safety, tolerability, and efficacy of REYOBIQ.
The therapy utilizes a proprietary nanoliposomal technology to deliver a highly concentrated dose of rhenium-186, a potent radioisotope, directly into the tumor via convection-enhanced delivery (CED).
This targeted approach is designed to maximize the destruction of cancer cells while minimizing radiation exposure to healthy surrounding brain tissue.