Organization and Operations	12 Months Ended
Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	1. Organization and Operations The Company Plus Therapeutics, Inc. 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. 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/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. Liquidity The Company incurred net losses of $20.3 million for the year ended December 31, 2022, and as of December 31, 2022, the Company had an accumulated deficit of $467.2 million and cash and cash equivalents of $18.1 million. Additionally, the Company used net cash of $13.0 million to fund its operating activities for the year ended December 31, 2022. The Company expects that its research and development expenditures will increase in absolute dollars in 2023 and beyond. As disclosed in more detail in Note 12, the Company has entered into various financing agreements and raised capital by issuing its common stock. The Company believes its current cash and cash equivalents will be sufficient to fund its operations for at least the next 12 months from the date these financial statements are issued. The Company continues to seek additional capital through strategic transactions and from other financing alternatives. If sufficient capital is not raised in the future, the Company may eventually 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. On May 24, 2022, the Company received notice from The Nasdaq Stock Market LLC (“Nasdaq”) that, because the closing bid price for the Company’s common stock had fallen below $1.00 per share for 30 consecutive business days, the Company no longer complied with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”). Nasdaq’s notice had no immediate effect on the listing or trading of the Company’s common stock. On November 22, 2022, the Company received a second letter from Nasdaq advising that the Company had been granted an additional 180 calendar days, or to May 22, 2023, 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, the Company has confirmed to Nasdaq that, if necessary, it will implement a reverse stock split of its outstanding common stock (if approved by the Company’s stockholders) to attempt to regain compliance. If the Company does not regain compliance within the additional compliance period, Nasdaq will provide notice that the Company’s 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.

Organization and Operations

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company

Plus Therapeutics, Inc. 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.

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/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.

Liquidity

The Company incurred net losses of $20.3 million for the year ended December 31, 2022, and as of December 31, 2022, the Company had an accumulated deficit of $467.2 million and cash and cash equivalents of $18.1 million. Additionally, the Company used net cash of $13.0 million to fund its operating activities for the year ended December 31, 2022. The Company expects that its research and development expenditures will increase in absolute dollars in 2023 and beyond.

As disclosed in more detail in Note 12, the Company has entered into various financing agreements and raised capital by issuing its common stock. The Company believes its current cash and cash equivalents will be sufficient to fund its operations for at least the next 12 months from the date these financial statements are issued.

The Company continues to seek additional capital through strategic transactions and from other financing alternatives. If sufficient capital is not raised in the future, the Company may eventually 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.

On May 24, 2022, the Company received notice from The Nasdaq Stock Market LLC (“Nasdaq”) that, because the closing bid price for the Company’s common stock had fallen below $1.00 per share for 30 consecutive business days, the Company no longer complied with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”).

Nasdaq’s notice had no immediate effect on the listing or trading of the Company’s common stock. On November 22, 2022, the Company received a second letter from Nasdaq advising that the Company had been granted an additional 180 calendar days, or to May 22, 2023, 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, the Company has confirmed to Nasdaq that, if necessary, it will implement a reverse stock split of its outstanding common stock (if approved by the Company’s stockholders) to attempt to regain compliance. If the Company does not regain compliance within the additional compliance period, Nasdaq will provide notice that the Company’s 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.