Plus Therapeutics Announces DSMB Approval to Proceed into Eighth Cohort in ReSPECT™ Glioblastoma Trial

AUSTIN, Texas, June 16, 2021 (GLOBE NEWSWIRE) — Plus Therapeutics, Inc. (Nasdaq: PSTV) (the “Company”), a clinical-stage pharmaceutical company developing novel, targeted therapies for rare and difficult to treat cancers, today announced that the Data and Safety Monitoring Board recommended the Company proceed to the eighth cohort of the Phase 1 dose escalation ReSPECT™ trial, which is evaluating the Company’s lead investigational drug, Rhenium NanoLiposome (RNL™), in patients with recurrent glioblastoma (GBM).

“We are pleased with the favorable safety profile observed thus far with RNL™ in recurrent GBM,” said Marc Hedrick, M.D., President and Chief Executive Officer of Plus Therapeutics. “Moving to cohort eight will allow us to continue to push the envelope in terms of addressable tumor size and maximum radiation dose delivered.”

Twenty-one patients with recurrent GBM have been treated in the ReSPECT™ trial across seven cohorts to date. In these patients, RNL™ has had no dose-limiting toxicities observed with absorbed radiation doses of up to 740 Gray per tumor.

The eighth cohort of the ReSPECT™ trial will implement a 40% increase in total radioactivity. The planned infused dose will be 31.2 millicuries in a volume of 12.3 milliliters (increased from 22.3 millicuries and 8.8 milliliters, respectively, used in cohort seven). The planned maximum flow rate will not change.

RNL™ is under investigation as a potentially safe, effective and convenient way to deliver a very high dose of radiation, possibly over 20 times greater than traditional external beam radiation therapy. This trial is supported by the U.S. National Institutes of Health/National Cancer Institute at three trial sites in the U.S., including UT Health Science Center San Antonio, UT Southwestern Medical Center and UT MD Anderson Cancer Center Houston.

The U.S. Food and Drug Administration has granted both Orphan Drug designation and Fast Track designation to RNL™ for the treatment of patients with GBM. Additional details about the ReSPECT™ trial are available at clinicaltrials.gov (NCT01906385).

The latest corporate information can be found on the Company’s Investor Relations page at ir.plustherapeutics.com/presentations.

About Plus Therapeutics, Inc.

Plus Therapeutics is a clinical-stage pharmaceutical company whose radiotherapeutic portfolio is concentrated on nanoliposome-encapsulated radionuclides for several cancer targets. Central to the Company’s drug development is a unique nanotechnology platform designed to reformulate, deliver and commercialize multiple drugs targeting rare cancers and other diseases. The platform is designed to facilitate new delivery approaches and/or formulations of safe and effective, injectable drugs, potentially enhancing the safety, efficacy and convenience for patients and healthcare providers. More information may be found at PlusTherapeutics.com and ReSPECT-Trials.com.

Cautionary Statement Regarding 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 “will,” “believe,” “plan,” “can,” “enable,” “design,” “intend,” “potential,” “expect,” “estimate,” “project,” “prospect,” “target,” “focus,” “anticipate,” “could,” “should,” 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 following: the design and potential of the Plus Therapeutics portfolio to reformulate, deliver and commercialize multiple novel, proprietary drugs targeting rare cancers and other diseases and to facilitate new delivery approaches and/or formulations of safe and effective, injectable drugs; the potential of the Company’s in-licensed portfolio of investigational drugs; the Company’s intent to advance its CNS oncology portfolio through the clinical development process; the ability of RNL to safely, effectively and conveniently deliver a very high dose of radiation directly into the brain tumor; anticipated benefits of strategic collaborations and license agreements, intellectual property, FDA approval process and government regulation; and the Company’s anticipated milestones and events, including with respect to additional sites, enrollment, pivotal trial planning, IND process, and clinical phase plans for RNL, pipeline expansion through additional drug development candidates, and partnership discussions for RNL, DocePLUS and DoxoPLUS; and future development and/or expansion of its product candidates and therapies in its markets. The forward-looking statements included in this press release are subject to a number of risks and uncertainties that may cause actual results to differ materially from those discussed in such forward-looking statements. These risks and uncertainties include, but are not limited to: the risk that the Company is not able to successfully develop product candidates that can leverage the FDA’s accelerated regulatory pathways; the early stage of the Company’s product candidates and therapies, the results of its research and development activities, including uncertainties relating to the clinical trials of its product candidates and therapies; the Company’s history of losses; the Company’s need for, and ability to raise, additional cash or obtain other sources of funding in the immediate future; the Company’s ability to: (a) obtain and maintain regulatory approvals, (b) continue as a going concern, (c) remain listed on the Nasdaq Capital Market, (d) to obtain or maintain sufficient levels of reimbursement for its tests, and (d) to repay or refinance some or all of its outstanding indebtedness; the outcome of the Company’s partnering/licensing efforts; market and economic conditions; the impact of the COVID-19 pandemic on the Company and the effectiveness of the efforts it has taken or may take in the future in response thereto; and additional risks described under the heading “Risk Factors” in the Company’s Securities and Exchange Commission filings, including in the Company’s annual and quarterly reports. 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.

Investor Contact
Peter Vozzo
Westwicke/ICR
(443) 377-4767
Peter.Vozzo@westwicke.com

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