Plus Therapeutics Updates on CNSide Assay and REYOBIQ Progress

Introduction

Plus Therapeutics, Inc. (NASDAQ: PSTV) is a clinical-stage pharmaceutical company headquartered in Houston, Texas. The company develops targeted radiotherapeutics that localize Rhenium-based radiation directly within tumors using proprietary nanoliposome and alginate microsphere delivery systems. Its lead candidate, REYOBIQ™ (rhenium Re-186 obisbemeda), is currently being evaluated in multicenter ReSPECT clinical trials for recurrent glioblastoma, leptomeningeal metastases, and pediatric brain cancers.

Corporate Structure

Founded in 2019 following a strategic refocus from Cytori Therapeutics, Plus Therapeutics employs between 11 and 50 professionals. President and Chief Executive Officer Marc H. Hedrick, M.D. oversees overall strategy and operations, while Chief Financial Officer Andrew Sims brings over 25 years of experience in financial leadership in mergers, acquisitions, and corporate capitalization. The company’s wholly-owned subsidiary, CNSide Diagnostics, LLC, is developing a proprietary cerebrospinal fluid assay platform aimed at central nervous system cancer diagnostics.

Recent Developments and News

On March 4, 2025, Plus Therapeutics restructured a previously announced $15.0 million equity financing to eliminate the potential dilution of up to 1.5 billion shares of common stock. Nasdaq notified the company on May 21, 2025, of its noncompliance with Listing Rule 5250(c)(1) due to a delayed Form 10-Q filing; Plus Therapeutics must submit a plan by July 21, 2025, which could be extended to November 17, 2025. On June 23, 2025, the U.S. Securities and Exchange Commission declared effective the company’s S-1 registration statement, and the company simultaneously withdrew its S-3 resale registration. A business update is scheduled for June 26, 2025, premarket, followed by a conference call and webcast at 9:00 a.m. ET. The company also announced the anticipated U.S. commercial rollout of its CNSide cerebrospinal fluid assay platform in the second half of 2025. The U.S. Food and Drug Administration has cleared the Investigational New Drug application for REYOBIQ for pediatric patients with supratentorial high-grade glioma and ependymoma, supported by a $3.0 million research grant from the U.S. Department of Defense.

Financial and Strategic Analysis

On June 26, 2025, PSTV opened at $0.4204 per share, reflecting an increase of 33.46 percent on a volume of 31,411,128 shares. A Schedule 13G/A filing dated June 25, 2025, indicated that The Hewlett Fund LP holds no beneficial ownership, suggesting limited institutional backing. The March equity restructuring simplified the company’s capital structure by reducing potential share overhang, while the effectiveness of the S-1 registration signals readiness to access public capital. The Nasdaq deficiency notification highlights the importance of timely SEC reporting to maintain compliance and investor confidence.

Market Position and Industry Context

Plus Therapeutics operates within the radiopharmaceutical and nanomedicine sectors, utilizing patented methods for encapsulating Rhenium radioisotopes in nanoliposomes for targeted beta-emitting therapy and gamma imaging. In addition to its CNS-focused REYOBIQ candidate, the company is advancing a next-generation Rhenium-188 radioembolization therapy for hepatocellular carcinoma and metastatic colorectal cancer. The CNSide diagnostic platform targets an estimated $6 billion U.S. central nervous system cancer diagnostics market, positioning Plus Therapeutics at the intersection of therapeutic development and diagnostic capabilities.

tl;dr

Plus Therapeutics will host a business update and webcast on June 26, 2025, detailing progress on its CNSide assay rollout in the second half of 2025 and the FDA-cleared pediatric IND for REYOBIQ. The company faces a July 21, 2025, deadline to submit a compliance plan to Nasdaq following a Form 10-Q delay, while its equity restructuring and S-1 effectiveness reflect efforts to optimize its capital strategy.