CNSide Diagnostics Secures National Coverage Agreement With Humana to Expand Access to CSF Tumor Cell Enumeration Test for Leptomeningeal Metastases Patients

CNSide Diagnostics, LLC, a wholly-owned subsidiary of Plus Therapeutics, announced a major milestone with the signing of a national coverage agreement with Humana, effective October 29, 2025. The agreement expands access to the CNSide® Cerebrospinal Fluid Tumor Cell Enumeration (TCE) laboratory-developed test, extending coverage to approximately 16 million additional patients across the United States. With this latest development, total coverage for the CNSide CSF TCE test now reaches 67 million people.

The CNSide® CSF assay is designed to support faster and more accurate diagnosis, treatment guidance, and continuous monitoring for patients affected by leptomeningeal metastases, a severe and challenging complication of cancer. The test has demonstrated superior performance compared to traditional methods, supported by nine peer-reviewed publications and results from the FORESEE clinical trial.

Since its initial launch in 2020, more than 11,000 CNSide® tests have been carried out at over 120 cancer centers across the country. The test has exhibited 92% sensitivity and 95% specificity, with real-world clinical data showing that it influenced treatment decisions in 90% of cases. These outcomes underscore its growing acceptance and clinical value within oncology care settings.

The CNSide® TCE test is offered exclusively through CNSide Diagnostics as a specialized testing service for healthcare providers in the United States, solidifying its position as a leading tool in the management of leptomeningeal metastases.