Plus Therapeutics Receives AMA PLA Code for CNSide CSF Tumor Cell Enumeration Test, Advancing Reimbursement and U.S. Commercial Adoption

New dedicated billing code facilitates payer reimbursement, supports clinician adoptions, and enables national utilization tracking

HOUSTON, April 07, 2026 -- Plus Therapeutics, Inc. (Nasdaq: PSTV) (“Plus” or the “Company”), a healthcare company developing and commercializing precision diagnostics and radiopharmaceuticals for central nervous system (CNS) cancers, today announces that the American Medical Association (AMA) has approved a new, Proprietary Laboratory Analyses (PLA) Current Procedural Terminology (CPT) code for its CNSide

Cerebrospinal Fluid (CSF) Tumor Cell Enumeration (TCE) test.

The dedicated billing code, 0640U, effective July 1, 2026, establishes a unique reimbursement identifier for the CNSide CSF TCE test, supporting payer claims processing and facilitating broader clinical adoptions as the Company continues the U.S. commercial launch of its CNS metastases diagnostic platform.

“Securing a dedicated PLA code for CNSide is an important milestone supporting the commercial launch of our CNSide Diagnostics business,” said Marc H. Hedrick, M.D., Plus Therapeutics President and Chief Executive Officer. “This coding milestone simplifies the reimbursement pathway for the CNSide CSF Tumor Cell Enumeration test and supports broader clinical adoption by oncologists and neurologists managing patients with leptomeningeal metastases. As awareness and payer coverage expand, we believe CNSide has the potential to become an important tool in the management of metastatic CNS cancers while contributing meaningfully to our revenue growth. Our diagnostics business continues to scale alongside our therapeutic pipeline, and we remain focused on building CNSide into a sustainable commercial franchise.”

Key implications of the newly assigned PLA code 0640U

• Supports payer reimbursement processes. Provides a dedicated billing code specific to the CNSide CSF Tumor Cell Enumeration test, enabling standardized claims submission and facilitating payer coverage determinations.
• Facilitates clinician adoption. Simplifies ordering and billing processes for clinicians and cancer centers evaluating patients with suspected leptomeningeal metastases.
• Enables national utilization tracking. PLA coding allows tracking of test utilization through claims data, supporting real-world evidence generation related to clinical outcomes and health economics.
• Supports ongoing U.S. commercial launch. The coding milestone strengthens the reimbursement infrastructure supporting the Company’s ongoing U.S. launch of CNSide CSF test.
  
  

About PLA Codes
Proprietary Laboratory Analyses (PLA) codes are issued by the American Medical Association to uniquely identify specific laboratory tests performed by a single laboratory or manufacturer. A dedicated PLA code allows healthcare providers to bill insurers using a standardized code that reflects the specific diagnostic test performed, facilitating claims processing and enabling tracking of test utilization across the healthcare system.

About CNSide Diagnostics, LLC
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. The CNSide CSF Assay Platform enables quantitative detection and molecular characterization of tumor cells in cerebrospinal fluid, providing actionable diagnostic information to physicians managing patients with leptomeningeal metastases, a serious and often difficult-to-diagnose complication of advanced cancer. Leptomeningeal metastases occur when cancer spreads to the membranes surround the brain and spinal cord and are associated with significant morbidity and limited diagnostic tools, highlighting the need for more sensitive diagnostic approaches.

About Plus Therapeutics
Headquartered in Houston, Texas, Plus Therapeutics, Inc. is a clinical-stage pharmaceutical company developing targeted radiotherapeutics for difficult-to-treat cancers of the central nervous system with the potential to enhance clinical outcomes. Combining image-guided local beta radiation and targeted drug delivery approaches, the Company is advancing a pipeline of product candidates with lead programs in leptomeningeal metastases (LM) and recurrent glioblastoma (GBM). The Company has built a supply chain through strategic partnerships that enable the development, manufacturing, and future potential commercialization of its products.