Company: PSTV
Filing Date: 2025-08-04
Form Type: DRS
Source: 0000950123-25-006916
Chunk: 8

Company: PLUS THERAPEUTICS, INC.
Filing Date: 2025-08-04
Form: DRS
Chunk 8
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 discussion of factors you should carefully consider before deciding to invest in our securities. |

Unless otherwise noted, the number of shares of common stock to be outstanding immediately after this offering is based on 99,264,526 shares outstanding as of July 30, 2025 and excludes, as of July 30, 2025:

| • |     | 1,230,272 shares of common stock issuable upon exercise of stock options outstanding under our equity incentive 
 plans, with a weighted-average exercise price of $3.79 per share;                                               |

2

Confidential Treatment Requested by Plus Therapeutics, Inc. Pursuant to 17 C.F.R. Section 200.83

| • |     | 76,025 shares of common stock reserved for future issuance under our 2015 New Employee Incentive Plan; |

| • |     | 47,742 shares of common stock reserved for future issuance under our 2020 Stock Incentive Plan; |

| • |     | 398 and 27,792 shares of common stock issuable upon conversion of 1,014 shares of Series B Convertible Preferred 
 Stock and 938 shares of Series C Preferred Stock, respectively;                                                  |

| • |     | 4,341,400 shares of common stock issuable upon exercise of pre-funded or 
 zero strike price warrants to purchase common stock; and                 |

| • |     | 3,141,993 shares of common stock issuable upon the exercise of warrants to purchase common stock, with a 
 weighted-average exercise price of $1.79 per share.                                                      |

3

Confidential Treatment Requested by Plus Therapeutics, Inc.

Pursuant to 17 C.F.R. Section 200.83

RISK FACTORS

Investing in our securities involves a high degree of risk. Before making an investment decision with respect to our securities, we urge you to carefully consider the risks described below and in the “Risk Factors” sections of our most recent Annual Report on Form 10-Kand Quarterly Reports on Form 10-Q,as well as our Current Reports on Form 8-K,filed with the SEC and incorporated by reference in this prospectus, and the other information contained in this prospectus. The risks and uncertainties incorporated by reference into this prospectus or described below are not the only ones we face. Additional risks and uncertainties not presently known or which we consider immaterial as of the date hereof may also materially harm our business and could result in a