Houston, Texas — August 14, 2025 — Leads & Copy — Plus Therapeutics, Inc. (Nasdaq: PSTV) announced positive data from a retrospective analysis of the CNSide Cerebrospinal Fluid (CSF) Assay Platform at the 2025 Society for Neuro-Oncology (SNO)/American Society of Clinical Oncology (ASCO) CNS Metastases Conference in Baltimore, Maryland.
The presentation, titled “The Oncogenic Flip in Patients with Leptomeningeal Metastatic Disease (LMD): Longitudinal Detection in Cerebrospinal Fluid Tumor Cells (CSF-TCs) Reveals Implications for Differential Treatment of the LMD Tumor,” was a retrospective, multi-center analysis of 613 CNSide assays ordered by 19 physicians from 5 institutions at 2 health systems for 218 individual patients. 74% of the patients were female and the cancers most analyzed were breast (n=105) and lung (n=65).
Data demonstrated CSF tumor cells detected in 67% (412/613) patients using CNSide. Of the patients, 66 underwent 2 or more CSF draws; 24 patients underwent 5 or more. 20% (13/66) of patients were found to have a flip in immunocytochemistry (ICC) detection; and 88% (58/66) of patients were found to have a flip in FISH probe detection.
According to Priya U. Kumthekar, M.D., Professor of Neurology and Medicine at Northwestern University, the CNSide CSF Assay Platform can be used to detect gene amplification on CSF tumor cells of patients with LM and, therefore, may provide therapeutic insights to specifically target the LM tumor. Dr. Kumthekar added that longitudinal CSF tumor cell analysis using CNSide may provide insights to modify treatment of the LM tumor over time.
CNSide Diagnostics, LLC is a wholly owned subsidiary of Plus Therapeutics, Inc. that develops and commercializes proprietary laboratory-developed tests, such as CNSide®, designed to identify tumor cells that have metastasized to the central nervous system in patients with carcinomas and melanomas.
Leptomeningeal metastases (LM) are a rare but severe complication of advanced cancer, affecting the fluid-lined structures of the central nervous system. LM occurs in approximately 5% of patients with metastatic cancer, but the actual incidence may be higher as it can be difficult to diagnose.
Plus Therapeutics, Inc. is a clinical-stage pharmaceutical company developing targeted radiotherapeutics for difficult-to-treat cancers of the central nervous system. The Company is advancing a pipeline of product candidates with lead programs in leptomeningeal metastases (LM) and recurrent glioblastoma (GBM).
Contact: CORE IR, investor@plustherapeutics.com
Source: Plus Therapeutics, Inc.
