Plus Therapeutics Shares Advance Following National Coverage Agreement with UnitedHealth

Technology and Healthcare Sector Sees Gains as Plus Therapeutics Announces Key Partnership

Market-Moving Event: UnitedHealth Agreement Drives Plus Therapeutics Shares

Plus Therapeutics Inc. (NASDAQ: PSTV) shares experienced a notable advance following the announcement of a national coverage agreement with UnitedHealthcare Insurance Company (NYSE: UNH) for its CNSide® Cerebrospinal Fluid Tumor Cell Enumeration test. The agreement, effective September 15, 2025, positions the diagnostic test for broader market access across the United States. In premarket trading, PSTV stock surged by as much as 60%, reflecting immediate investor enthusiasm.

The CNSide® Platform: Expanding Diagnostic Reach

The core of the recent market activity centers on the CNSide® Cerebrospinal Fluid (CSF) Assay Platform. This laboratory-developed test (LDT), offered exclusively through CNSide Diagnostics, LLC, a wholly-owned subsidiary of Plus Therapeutics, is designed to support rapid diagnoses, treatment monitoring, and treatment guidance for patients afflicted with leptomeningeal metastases. This severe complication occurs when cancer cells spread to the cerebrospinal fluid and the membranes surrounding the brain and spinal cord.

The agreement with UnitedHealthcare is set to extend coverage for the CNSide® test to over 51 million people throughout the U.S. Clinical utility of the CNSide® test has been robustly supported by nine peer-reviewed publications and the FORESEE clinical trial, demonstrating superior performance over standard care. Since 2020, more than 11,000 CNSide® tests have been conducted at over 120 U.S. cancer institutions, with reported high sensitivity of 92% and specificity of 95%, influencing treatment decisions in 90% of cases. The recent CMS accreditation for CNSide Diagnostics’ Houston-based laboratory further solidifies its operational readiness and eligibility for reimbursement.

Analysis of Market Reaction: Revenue Potential and Strategic Positioning

The market's positive reaction to Plus Therapeutics' announcement underscores the perceived financial and strategic benefits of the UnitedHealthcare partnership. By securing national coverage, Plus Therapeutics significantly expands the total addressable market for its CNSide® platform, which is estimated to be approximately $6 billion in the U.S. This expansion is expected to translate into meaningful revenue contributions for the CNSide Diagnostics subsidiary, anticipated to begin in fiscal year 2026.

Despite reporting revenue of $5.82 million in 2024—an 18.54% increase year-over-year—and a net loss of -$12.98 million, the coverage agreement signals a potential inflection point for the company's financial trajectory. The substantial investment of over $300 million in the CNSide technology's core development highlights its long-term strategic importance to the company.

Broader Context and Implications: Analyst Outlook and Institutional Movements

The agreement positions Plus Therapeutics as a more prominent player in the specialized diagnostic market for leptomeningeal metastases. For UnitedHealth Group, a healthcare and well-being company with annual revenues exceeding $422 billion and a market capitalization of $318.63 billion, the inclusion of CNSide® into its covered services reflects a commitment to advanced diagnostic solutions.

Analyst sentiment surrounding PSTV is largely bullish, with a consensus "Strong Buy" rating. Over the past six months, four analysts have issued price targets for PSTV, with a median target of $4.0. Individual targets range from $3.0 (Jason McCarthy, Maxim Group; Sean Lee, HC Wainwright & Co.) to $5.0 (Jason Kolbert, D. Boral Capital) and an outlier of $20.5 (Edward Woo, Ascendiant Capital). These targets suggest a significant potential upside from the current price levels.

Institutional investor activity in Q2 2025 showed mixed but active participation. Notable increases in holdings included JANE STREET GROUP, LLC adding 117,454 shares and UBS GROUP AG adding 54,201 shares. Conversely, HRT FINANCIAL LP and AIGH CAPITAL MANAGEMENT LLC (Q1 2025) reduced their positions, indicating some divergence in institutional strategy.

Looking Ahead: Execution and Revenue Realization

The immediate focus for Plus Therapeutics will be on the effective implementation of the UnitedHealthcare agreement, with the coverage becoming effective on September 15, 2025. Investors will monitor the company's progress in converting expanded access into tangible revenue, particularly as it approaches fiscal year 2026, when meaningful contributions from CNSide Diagnostics are anticipated.

While the agreement significantly de-risks market access for the CNSide® test, the company's press release includes forward-looking statements. The actual impact on revenue and profitability remains a key area for observation, as does the potential for broader market penetration given the exclusive nature of the CNSide® offering through its subsidiary. The successful integration into UnitedHealthcare's network and sustained clinical adoption will be crucial determinants of Plus Therapeutics' long-term financial performance and its role in the specialized oncology diagnostics landscape.