Plus and Harvard analysis shows CNSide enables early diagnosis and better clinical decision-making
reducing healthcare costs by 40%

Presentation receives blue-ribbon recognition at the ISPOR Annual Meeting, the premier global gathering for health economics and outcomes research

HOUSTON, May 26, 2026 (GLOBE NEWSWIRE) -- 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 announced the presentation of a new health economics study evaluating the economic impact of earlier detection and therapeutic management of LM using the CNSide cerebrospinal fluid (CSF) assay. The Company believes that this cost-of-care analysis underscores that earlier LM diagnosis and therapeutic management enabled by CNSide may reduce overall LM-related healthcare costs by approximately 33-47%. These savings are driven by earlier therapeutic intervention, improved treatment precision, and reduced hospitalizations. Further, the recently announced payer agreements validate the findings as Plus continues commercialization of the assay in the United States.

The data was presented at the ISPOR 2026 Annual Meeting, the leading global scientific conference focused on health economics and outcomes research (HEOR), bringing together researchers, healthcare decision-makers, and payer stakeholders. The meeting took place May 17-20, 2026, in Philadelphia, PA.

“These findings are confirmation of discussions we have had with payers regarding the value provided by CNSide’s ability to detect and monitor tumor cells in cerebrospinal fluid, providing clinicians with actionable information earlier in the disease course,” said Randy Goodman, Ph.D., MHA, Vice President of Value Strategy & HEOR. “Health economics data are an important determinant in payer decision making and these data suggest the potential cost savings associated with earlier intervention and optimized management.”

Presentation Highlights
The poster, titled, “ Economic Impact of Earlier Detection and Therapeutic Management of Leptomeningeal Metastases Using CNSide: A Cost-of-Care Analysis, ” co-authored by CNSide Diagnostics and Harvard T.H. Chan School of Public Health, highlighted the following:

  • Late-stage LM diagnosis is associated with substantial healthcare costs, including median inpatient admissions of ~$20,000 (Interquartile range (IQR) $10,000-$30,000)
  • Total LM-related costs may exceed $100,000 per month, driven by repeated imaging, LM-directed therapies, and palliative care
  • Earlier detection and treatment optimization enabled by CNSide may reduce overall LM-related healthcare costs by ~40% (33%-47%)
  • Potential savings are driven by earlier therapeutic intervention, improved treatment precision, reduced adverse events and hospitalizations, and potential improvements in quality-adjusted outcomes
  • The analysis also highlights the challenges of quantifying LM costs due to claims bundling with primary cancer treatment

Notably, the poster received Blue Ribbon recognition, an honor awarded to the top 5% of presentations at ISPOR. The analysis utilized published literature, real-world data, and healthcare claims databases to estimate direct and indirect costs associated with late-stage LM diagnosis.   Additional information on ISPOR 2026 and the poster can be found here .

About Leptomeningeal Metastases
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, with breast cancer, lung cancer, and melanoma being the most common sources. Median survival is typically 2-6 months, and effective treatment options are limited, highlighting the urgent need for novel therapies.

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 of the cerebrospinal fluid (CSF) that informs and improves the management of patients with leptomeningeal metastases.

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. The Company’s commercial diagnostic, CNSide®, is a high-complexity cerebrospinal fluid (CSF) assay platform that supports the detection and management of leptomeningeal metastases (LM). The Company’s lead therapeutic candidate, REYOBIQ™ (rhenium Re186 obisbemeda), is in clinical development for LM and recurrent glioblastoma (GBM), combining image-guided local beta radiation with targeted drug delivery. Plus has built a supply chain through strategic partnerships that enable the development, manufacturing, and potential future commercialization of its products. For more information, visit 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. 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," "anticipate" "intend," "believe," "estimate," "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. The forward-looking statements included in this press release could differ materially from those expressed or implied by these forward-looking statements because of risks, uncertainties, and other factors that include, but are not limited to, the following: the Company’s ability to commercialize CNSide and to achieve and sustain payer coverage and reimbursement for the assay; the timing, scope and outcomes of the Company’s clinical studies, including ReSPECT-LM and ReSPECT-GBM; the Company’s ability to obtain regulatory approvals; the Company’s reliance on third-party manufacturers and supply chain partners; the Company’s ability to raise additional capital on reasonable terms or at all; available cash on hand; and changes in local or national economic conditions. This list of risks, uncertainties, and other factors is not complete. Any or all forward-looking statements the Company makes may turn out to be wrong and can be affected by inaccurate assumptions the Company might make or by known or unknown risks, uncertainties, and other factors, including those identified in this press release. Plus Therapeutics discusses some of these matters more fully, as well as certain risk factors that could affect Plus Therapeutics’ business, financial condition, results of operations, and prospects, in its reports filed with the SEC, including Plus Therapeutics’ annual report on Form 10-K for the fiscal year ended December 31, 2025, 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. There may be events in the future that the Company is unable to predict, or over which it has no control, and its business, financial condition, results of operations and prospects may change in the future. 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.

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