PSTV Stock Skyrockets on FDA's Orphan Drug Tag for Cancer Therapy

Core Viewpoint - Plus Therapeutics, Inc. (PSTV) experienced a significant stock increase of 311.4% on March 6 after receiving Orphan Drug Designation (ODD) from the FDA for its lead candidate, rhenium (186Re) obisbemeda, aimed at treating leptomeningeal metastases in lung cancer patients [1][2]. Company Developments - The FDA's ODD supports the development of treatments for rare disorders affecting fewer than 200,000 individuals in the U.S., providing seven years of market exclusivity post-approval, tax credits for clinical studies, and exemptions from certain FDA fees, including a $4.3 million fee in 2025 [2]. - Rhenium (186Re) obisbemeda is a novel injectable radiotherapy designed for targeted high-dose radiation in central nervous system tumors, potentially improving patient outcomes [4]. - PSTV has completed enrollment in the ReSPECT-LM phase I study, assessing the safety and efficacy of rhenium (186Re) obisbemeda in patients with leptomeningeal metastases, and is advancing to phase II and phase I multiple-dose studies [5]. - The company is also evaluating rhenium (186Re) obisbemeda in the phase I/II ReSPECT-GBM study for recurrent glioblastoma and plans to develop it for pediatric brain cancers [6]. Market Performance - Over the past year, PSTV shares have declined by 14.8%, while the industry average decrease was 9.9% [3].