Plus Therapeutics Expands Market Access for CNSide® Cancer Assay with Humana National Coverage Agreement

Plus Therapeutics, Inc. (Nasdaq: PSTV) has announced a significant expansion in market access for its proprietary CNSide® Cerebrospinal Fluid (CSF) Assay. Through its wholly-owned subsidiary, CNSide Diagnostics, LLC, the company secured a national coverage agreement with Humana, Inc. (NYSE: HUM), a leading health and well-being company. The agreement, effective October 29, 2025, extends coverage for the advanced diagnostic test to approximately 16 million people across the United States.

This strategic partnership increases the total number of individuals with policy coverage for the CNSide® test to 67 million, marking a critical milestone in the commercialization of this innovative diagnostic tool for metastatic central nervous system (CNS) cancer.

Advanced Diagnostic Capabilities and Market Impact

The CNSide® CSF Assay Platform is a laboratory-developed test designed to provide rapid and accurate diagnosis, treatment monitoring, and therapeutic guidance for patients with leptomeningeal metastases (LM), a severe complication where cancer spreads to the fluid-filled space surrounding the brain and spinal cord.

Key performance metrics and market adoption underscore the test’s clinical value:

• High Clinical Utility: The test’s superior performance compared to standard-of-care methods is supported by nine peer-reviewed publications and data from the FORESEE clinical trial.
• Proven Performance: CNSide® demonstrates high sensitivity (92%) and specificity (95%), enabling precise detection of tumor cells in the cerebrospinal fluid.
• Real-World Influence: Since 2020, over 11,000 tests have been performed at more than 120 U.S. cancer institutions, influencing treatment decisions in an estimated 90% of cases.

The test is exclusively available through CNSide Diagnostics as a service provided to healthcare professionals, solidifying its position as a specialized and critical component in the management of complex CNS cancers.

About Humana

Humana Inc. (NYSE: HUM) is committed to putting health first – for their teammates, their customers, and their company. Through  Humana’s insurance services, and  their CenterWell health care services, they make it easier for the millions of people they serve to achieve their best health – delivering the care and service they need, when they need it. These efforts are leading to a better quality of life for people with Medicare, Medicaid, families, individuals, military service personnel, and communities at large. Learn more about what they offer at Humana.com and at CenterWell.com.

About Plus Therapeutics

Plus Therapeutics, headquartered in Houston, Texas, is a clinical-stage pharmaceutical company focused on developing targeted radiotherapeutics for difficult-to-treat CNS cancers, including leptomeningeal metastases and recurrent glioblastoma. The company’s strategy combines image-guided local beta radiation with targeted drug delivery to enhance clinical outcomes. The commercial expansion of the CNSide® assay complements this core mission by providing an essential diagnostic tool that can guide the application of its therapeutic candidates.

This agreement with Humana represents a key step in broadening reimbursement support and accelerating the commercial uptake of the CNSide® CSF Assay, which could generate a new revenue stream and support the continued development of the company’s therapeutic pipeline.

For more information about Plus Therapeutics please visit www.plustherapeutics.com.