Plus Therapeutics Announces CAP Accreditation of CNSide® Diagnostics Clinical Laboratory

HOUSTON, June 04, 2026 (GLOBE NEWSWIRE) -- CNSide Diagnostics, LLC, a wholly owned subsidiary of Plus Therapeutics, Inc. (NASDAQ:PSTV) ("Plus" or the "Company"), a healthcare company advancing precision diagnostics and radiopharmaceuticals for central nervous system (CNS) cancers, today announces that its Houston-based clinical laboratory has received accreditation from the College of American Pathologists (CAP) following a recent on-site inspection conducted under the CAP Laboratory Accreditation Program.

The CAP Laboratory Accreditation Program is internationally recognized as the "gold standard" in laboratory accreditation. As part of this distinction, CNSide Diagnostics' laboratory underwent a rigorous on-site inspection evaluating clinical protocols, documentation, quality control procedures, personnel qualifications, equipment, facilities, safety programs, and overall laboratory management. CNSide Diagnostics now joins more than 8,000 CAP-accredited laboratories worldwide.

"Achieving CAP accreditation is a defining milestone for CNSide Diagnostics and an important validation of the quality, rigor, and operational discipline our team has built into every aspect of our laboratory," said Russ Bradley, President and General Manager, CNSide Diagnostics, LLC. "Building on its CLIA-certified laboratory operations, CAP accreditation further strengthens CNSide Diagnostics' quality framework, positioning the company to deliver the highest standard of testing to clinicians and patients, support broader payer coverage and reimbursement, and accelerate the U.S. commercial expansion of the CNSide® CSF Assay Platform for patients with, or at risk for, leptomeningeal metastases and other CNS cancers."

"CAP accreditation is a meaningful validation of the discipline and dedication of our laboratory team," said Dr. Jonathan Stein, Medical Director of CNSide Diagnostics, LLC. "This milestone reflects the robust processes we have established across laboratory operations, quality management, and personnel training, and we believe it will support continued adoption of CNSide by clinicians seeking high-quality CNS cancer diagnostic testing."

"CNSide Diagnostics demonstrates leadership, innovation, and a passionate commitment to standards of excellence while providing the highest quality services, ultimately for patients," said Earle S. Collum, MD, FCAP, chair of the CAP's Council on Accreditation. "The College of American Pathologists congratulates CNSide Diagnostics on its recent CAP Accreditation."

CAP accreditation is expected to support several strategic and commercial objectives, including:

• Reinforcing clinical confidence: Providing oncologists, neuro-oncologists, and health systems with additional assurance regarding the analytical and operational quality of the CNSide® CSF Assay Platform

• Advancing payor engagement: Supporting discussions with commercial and government payors as CNSide Diagnostics pursues broader coverage and reimbursement for CNSide® testing

• Facilitating health system adoption: Helping meet the accreditation and quality expectations of leading academic medical centers, integrated delivery networks, and reference laboratories

• Enabling future menu expansion: Strengthening the quality infrastructure needed to support additional laboratory-developed tests on the CNSide® platform

About the College of American Pathologists 

As the world's largest organization of board-certified pathologists and leading provider of laboratory accreditation and proficiency testing programs, the College of American Pathologists (CAP) serves patients, pathologists, and the public by fostering and advocating excellence in the practice of pathology and laboratory medicine worldwide. For more information, visit the CAPNewsroom, CAP.org and yourpathologist.org to watch pathologists at work and see the stories of the patients who trust them with their care.

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 analysis and molecular characterization of tumor cells and circulating tumor DNA in the cerebrospinal fluid (CSF) that inform and improve the management of patients with leptomeningeal metastases. For more information, visit https://cnside-dx.com.

About Plus Therapeutics

Headquartered in Houston, Texas, Plus Therapeutics, Inc. is a healthcare company developing and commercializing precision diagnostics and radiopharmaceuticals for central nervous system (CNS) cancers. Combining image-guided local beta radiation and targeted drug delivery approaches with proprietary CSF-based diagnostics, 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. For more information, visit https://www.plustherapeutics.com.

Forward-Looking Statements

This press release contains statements that may be deemed "forward-looking statements" within the meaning of U.S. securities laws, including statements regarding clinical operations, expected commercial activities, and upcoming developments. All statements in this press release other than statements of historical fact are forward-looking statements. These forward-looking statements may be identified by future verbs, as well as terms such as "expect," "potential," "anticipate," "intend," "believe," "estimate," "plan," "will," and similar expressions or the negatives thereof. Such statements are based upon certain assumptions and assessments made by management in light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe to be appropriate.

These statements include, without limitation, statements regarding the anticipated benefits of CAP accreditation, the potential market for the CNSide® CSF Assay Platform, the timing and pace of U.S. commercial launch and expansion, expectations regarding payor coverage, reimbursement, and billing code expansion for the CNSide® CSF Assay, the development and clinical utility of the CNSide CSF Assay, and expectations as to the Company's future performance, including next steps in developing the Company's product candidates.

The forward-looking statements included in this press release could differ materially from those expressed or implied because of risks, uncertainties, and other factors that include, but are not limited to: the Company's ability to maintain regulatory accreditations and certifications; the Company's ability to successfully commercialize the CNSide CSF Assay Platform; the Company's ability to obtain and maintain favorable coverage, reimbursement, and billing codes from commercial and government payors; the Company's ability to complete its pre-clinical or clinical studies; available cash on hand; the Company's ability to raise additional capital on reasonable terms or at all; and changes in local or national economic conditions. This list of risks, uncertainties, and other factors is not complete.

Plus Therapeutics discusses some of these matters more fully, as well as certain risk factors that could affect the Company's business, financial condition, results of operations, and prospects, in its reports filed with the SEC, including its annual report on Form 10-K, quarterly reports on Form 10-Q, and current reports on Form 8-K. These filings are available for review through the SEC's website at www.sec.gov. Accordingly, you should not place undue reliance on the forward-looking statements made in this press release, which speak only as of its date. The Company assumes no responsibility to update or revise any forward-looking statements to reflect events, trends or circumstances after the date they are made unless the Company has an obligation under U.S. federal securities laws to do so.

Investor Contact

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