Plus Therapeutics Expands CNSide Assay Platform to State of California
Rhea-AI Summary
Plus Therapeutics (Nasdaq: PSTV) announced that CNSide Diagnostics, its wholly owned subsidiary, has received state lab licenses to provide the CNSide® CSF Tumor Cell Enumeration (TCE) laboratory-developed test in California, Rhode Island and Maryland, bringing coverage to 48 of 50 U.S. states and serving over 90% of the U.S. population.
The CNSide® CSF assay supports diagnosis and treatment monitoring for leptomeningeal metastases, reports >11,000 tests at 120+ U.S. cancer institutions since 2020, and cites 92% sensitivity, 95% specificity, and influence on treatment decisions in 90% of cases. Tests are performed at a CLIA-certified facility in Houston and are available exclusively through CNSide Diagnostics.
Positive
- State licensure expanded to 48 U.S. states (>90% population)
- 11,000+ CNSide tests performed since 2020 at 120+ institutions
- Assay reports 92% sensitivity and 95% specificity
- Test results influenced treatment decisions in 90% of cases
Negative
- Not licensed in 2 U.S. states
- Testing performed exclusively at a single CLIA facility in Houston
Key Figures
Market Reality Check
Peers on Argus
Peer moves were mixed, with RADX up 0.71%, RNXT up 3.93%, and others like BRNS down 9.74%, suggesting stock-specific rather than broad sector momentum.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Dec 09 | Hiring & grants | Positive | +6.3% | Subsidiary hires and inducement equity grants to scale CNSide operations. |
| Dec 04 | Clinical data update | Positive | +9.8% | Multiple REYOBIQ clinical data presentations with supportive safety and efficacy signals. |
| Dec 01 | Conference presentation | Positive | -4.4% | Announcement of upcoming Phase 1 LM data presentation at SABCS. |
| Nov 24 | FDA meeting update | Positive | +8.0% | Completion of Type B FDA meeting on pivotal LM trial design and next steps. |
| Nov 20 | Coverage expansion | Positive | -0.3% | Humana national coverage expanding CNSide policy reach to 67M covered lives. |
Recent news, particularly clinical and commercial updates, often saw positive price reactions, though two CNSide-related coverage/clinical communication events showed mild negative divergence.
Over the past month, Plus Therapeutics reported multiple milestones tied to CNS cancers and CNSide. On Nov 20, CNSide secured Humana national coverage, yet shares slipped 0.35%. Subsequent FDA meeting and clinical data updates in late November and early December produced gains of 7.98% and 9.75%. Team expansion and inducement grants on Dec 9 lifted the stock 6.35%. Today’s expansion of CNSide’s assay licensing to 48 states builds on that commercialization and access narrative.
Market Pulse Summary
This announcement extends CNSide’s cerebrospinal fluid tumor cell enumeration assay to 48 states, covering over 90% of the U.S. population. It builds on prior coverage wins and clinical data, with more than 11,000 tests run at over 120 cancer institutions and reported 92% sensitivity and 95% specificity. In context of recent filings highlighting continued losses and capital needs, investors may focus on how growing access and utilization of CNSide contributes to scaling this diagnostics platform over time.
Key Terms
cerebrospinal fluid medical
leptomeningeal metastases medical
AI-generated analysis. Not financial advice.
CNSide Diagnostics now licensed in 48 U.S. States covering over
HOUSTON, Dec. 11, 2025 (GLOBE NEWSWIRE) -- CNSide Diagnostics, LLC, a wholly-owned subsidiary of Plus Therapeutics, Inc. (Nasdaq: PSTV) (“Plus” or the “Company”), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system (CNS) cancers, announces that it has been granted lab licenses to provide the CNSide® Cerebrospinal Fluid (CSF) Tumor Cell Enumeration (TCE) laboratory developed test (LDT) in California, Rhode Island and Maryland.
“CNSide Diagnostics is now licensed to provide our proprietary testing service in 48 of 50 U.S. states and obtaining state licensure is a key enabler of our plan to bring the benefits of CNSide CSF testing to the broadest possible set of patients with CNS cancers,” said Russ Bradley, CNSide Diagnostics, LLC President and General Manager. “We remain focused on executing on U.S. market access and launch strategy and look forward to continued expansion of coverage across payors and states.”
The CNSide® CSF Assay Platform supports rapid diagnoses, treatment monitoring, and treatment guidance for patients with leptomeningeal metastases. The superior clinical utility of CNSide® over standard of care has been shown in 9 peer-reviewed publications, the FORESEE clinical trial, and has been validated in the market through real-world use.
More than 11,000 CNSide® tests have been performed at over 120 U.S. cancer institutions since 2020, delivering high sensitivity (
This test is available exclusively through CNSide Diagnostics, LLC. as a testing service provided to health care professionals in the U.S.
CNSide Diagnostics, LLC performs the tests in its CLIA certified facility in Houston, TX.
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 that informs and improves the management of patients with leptomeningeal metastases. For more information, visit https://www.cnside-dx.com/.
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. 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 the market for CNSide and the potential launch and test coverage expansion, including plans for additional payor agreements. 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,” “anticipating,” “planning” 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 maintain the listing of its common stock on Nasdaq; the early stage of the Company’s product candidates and therapies; the results of the Company’s research and development activities, including uncertainties relating to the clinical trials of its product candidates and therapies; the Company’s liquidity position and capital resources and its ability to raise additional cash; the outcome of the Company’s partnering/licensing efforts, risks associated with laws or regulatory requirements applicable to it; market conditions, product performance, litigation or potential litigation, and competition within the cancer diagnostics and therapeutics field; ability to develop and protect proprietary intellectual property or obtain licenses to intellectual property developed by others on commercially reasonable and competitive terms; challenges associated with radiotherapeutic manufacturing, production and distribution capabilities necessary to support the Company’s clinical trials and any commercial level product demand; and material security breach or cybersecurity attack affecting the Company’s operations or property. This list of risks, uncertainties, and other factors is not complete. The Company discusses some of these matters more fully, as well as certain risk factors that could affect its business, financial condition, results of operations, and prospects, in its reports filed with the SEC, including its annual report on Form 10-K for the fiscal year ended December 31, 2024, 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. Any or all forward-looking statements the Company makes may turn out to be wrong and can be affected by inaccurate assumptions it might make or by known or unknown risks, uncertainties, and other factors, including those identified in this press release. 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
CORE IR
investor@plustherapeutics.com
FAQ
What did Plus Therapeutics (PSTV) announce on December 11, 2025 about CNSide licensing?
How much U.S. population coverage does CNSide Diagnostics now have for the CNSide test (PSTV)?
How many CNSide tests has Plus Therapeutics reported and where were they performed?
What clinical performance metrics did Plus Therapeutics report for the CNSide CSF assay (PSTV)?
Is the CNSide CSF test widely available to U.S. clinicians now that PSTV expanded licenses?
