The Company

Plus Therapeutics, Inc. (the “Company”) is a clinical-stage pharmaceutical company focused on the development, manufacture and commercialization of complex and innovative treatments for patients battling cancer and other life-threatening diseases. CNSide Diagnostics, LLC is a wholly owned subsidiary of Plus Therapeutics, Inc. that develops and commercializes proprietary laboratory-developed tests, such as the CNSide Test, designed to identify tumor cells that have metastasized to the central nervous system in patients with carcinomas and melanomas.

Certain Risks and Uncertainties

The Company’s prospects are subject to the risks and uncertainties frequently encountered by companies in the early stages of development and commercialization, especially those companies in rapidly evolving and technologically advanced industries such as the biotech and medical device field. The Company’s future viability largely depends on its ability to complete development of new products and receive regulatory approvals for those products. No assurance can be given that the Company’s new products will be successfully developed, regulatory approvals will be granted, or acceptance of these products will be achieved.

Going Concern

The Company incurred net losses of $22.4 million for the year ended December 31, 2025, and as of December 31, 2025, the Company had an accumulated deficit of $515.9 million and cash, cash equivalents, restricted cash, and short-term investments of $13.1 million. The Company includes restricted cash and cash equivalents in its liquidity assessment because the restrictions are expected to be released within one year after the date that the financial statements in this Form 10-K are issued, at which time the funds will be available to support working capital requirements. Additionally, the Company used net cash of $20.8 million to fund its operating activities for the year ended December 31, 2025. The Company expects that its research and development expenditures will increase in absolute dollars in 2026 and beyond. These factors raise substantial doubt about the Company’s ability to continue as a going concern.

As disclosed in more detail in Note 15, the Company has entered into various financing agreements and raised capital by issuing its common stock. Additionally, in January 2026, the Company entered into an underwriting agreement in which it raised net proceeds of approximately $13.3 million after deducting the underwriting discounts and commissions and other estimated offering expenses payable by the Company.

The Company continues to seek additional capital from other financing alternatives and other sources in order to ensure adequate funding is available to allow the Company to continue research and product development activities. If sufficient capital is not raised, the Company will at a minimum need to significantly reduce or curtail its research and development and other operations, and this would negatively affect its ability to achieve corporate growth goals.

Should the Company fail to raise additional cash, it would have a material adverse impact on its operations.

The accompanying consolidated financial statements have been prepared assuming the Company will continue to operate as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business, and do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classifications of liabilities that may result from uncertainty related to its ability to continue as a going concern.

Nasdaq Listing Compliance

Minimum Stockholders’ Equity Requirement

In March 2024, the Company received notice from the Listing Qualifications staff of Nasdaq (the “Staff”), notifying it that it no longer maintained at least $2.5 million in stockholders’ equity, as required under Nasdaq Listing Rule 5550(b)(1) (the “Minimum Stockholders’ Equity Requirement”), and also did not meet any other alternative standard. On October 22, 2024, the Company held its first hearing before a Nasdaq panel, as a result of which it received additional time, or until March 4, 2025, to regain compliance. A second hearing was held on July 15, 2025. On July 22, 2025, the panel for its second hearing issued a decision granting its request for continued listing on Nasdaq, subject to the Company demonstrating compliance with (1) the Minimum Stockholders’ Equity Requirement by August 14, 2025; and (2) the Minimum Bid Requirement (as defined below) by September 8, 2025. On August 22, 2025, the Company received a letter (the “August 2025 Letter”) from Nasdaq confirming its compliance with Nasdaq Listing Rule 5550(b). Specifically, the August 2025 Letter confirmed that the Company was in compliance with both (1) Nasdaq Listing Rule 5550(b)(2), which requires a market value of listed securities of at least $35 million and (2) the alternative stockholders’ equity threshold under Nasdaq Listing Rule 5550(b)(1), which is the Minimum Stockholders’ Equity Requirement. The August 2025 Letter also provided that, solely with respect to the Minimum Stockholders’ Equity Requirement, it remain subject to a one-year panel monitoring period, through August 22, 2026. If, within that one-year monitoring

period, the Staff determines that the Company no longer satisfies the Minimum Stockholders’ Equity Requirement (and it is not then in compliance with one of the alternative standards under Nasdaq Listing Rule 5550(b)), it will not be permitted to provide the Staff with a plan of compliance and the Staff is not permitted to grant additional time to regain compliance with the Minimum Stockholders’ Equity Requirement nor will it be afforded an applicable cure or compliance period. Instead, the Staff will issue a delist determination letter, and it will have an opportunity to request a new hearing before the Nasdaq Hearings Panel, which request would stay any further action by the Staff pending the ultimate outcome of the hearing.

Minimum Bid Requirement

On May 16, 2025, the Company received notice from Nasdaq that, because the closing bid price for its common stock had fallen below $1.00 per share for 30 consecutive business days, it no longer complied with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”). The Company was provided an initial compliance period of 180 calendar days, or until November 12, 2025, to regain compliance with the Minimum Bid Requirement. To regain compliance, the closing bid price of its common stock must meet or exceed $1.00 per share for a minimum of 10 consecutive business days prior to November 12, 2025.

On November 13, 2025, the Company received a second letter from the Nasdaq Staff advising that it had been granted an additional 180 calendar days, or until May 11, 2026, to regain compliance with the Minimum Bid Requirement, in accordance with Nasdaq Listing Rule 5810(c)(3)(A).

The Company intends to continue to actively monitor the closing bid price of its common stock and will evaluate available options to regain compliance with the Minimum Bid Requirement. Specifically, it has confirmed to Nasdaq that, if necessary, it will implement a reverse stock split of its outstanding common stock to attempt to regain compliance. If the Company does not regain compliance within the additional compliance period, Nasdaq will provide notice that its common stock will be subject to delisting. The Company would then be entitled to appeal that determination to a Nasdaq hearings panel. There can be no assurance that the Company will regain compliance with the Minimum Bid Requirement during the 180-day additional compliance period or maintain compliance with the other Nasdaq listing requirements.