PLUS THERAPEUTICS INC

September 30, 2024

1. Basis of Presentation and New Accounting Standards

The accompanying unaudited condensed consolidated financial statements for the three and nine months ended September 30, 2024 and 2023 have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for annual financial statements. The condensed balance sheet at December 31, 2023 has been derived from the audited financial statements at December 31, 2023, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements.

On May 17, 2024, Plus Therapeutics, Inc. (the “Company”) established a wholly owned subsidiary, CNSide Diagnostics, LLC (“CNSide LLC”), a Delaware limited liability company. CNSide LLC was set up to operate the CNSide diagnostic portfolio, consisting of the intellectual property acquired by the Company from Biocept, Inc. (“Biocept”) in April 2024 (See Note 8, Biocept Asset Acquisitions, for further details).

In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the financial position and results of operations of the Company and its wholly owned subsidiary, CNSide LLC, have been included. Operating results for the three and nine months ended September 30, 2024 are not necessarily indicative of the results that may be expected for the remainder of the year ending December 31, 2024. These condensed consolidated financial statements should be read in conjunction with the financial statements and notes therein included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the Securities and Exchange Commission on March 5, 2024.

Grant Revenue Recognition

In applying the provisions of Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”), the Company has determined that government grants are out of the scope of ASC 606 because the funding entities do not meet the definition of a “customer”, as defined by ASC 606, as the Company does not consider there to be a transfer of control of goods or services. With respect to each grant, the Company determines if it has a collaboration in accordance with ASC Topic 808, Collaborative Arrangements (“ASC 808”). For grants outside the scope of ASC 808, the Company applies International Accounting Standards No. 20, Accounting for Government Grants and Disclosure of Government Assistance, by analogy, and revenue is recognized when the Company incurs expenses related to the grant for the amount the Company is entitled to under the provisions of the contract.

The Company also considers the guidance in ASC Topic 730, Research and Development, which requires an assessment, at the inception of each grant, of whether each grant agreement is a liability. If the Company is obligated to repay funds received regardless of the outcome of the related research and development activities, then the Company is required to estimate and recognize that liability. Alternatively, if the Company is not required to repay the funds, then payments received are recorded as revenue or contra-expense as the expenses are incurred.

Deferred grant liability represents grant funds received or receivable for which the allowable expenses have not yet been incurred as of the balance sheet date.

Warrants

Warrants are accounted for as either derivative liabilities or as equity instruments depending on the specific terms of the agreement in accordance with applicable accounting guidance provided in ASC Topic 815 -Derivatives and Hedging. Equity-classified instruments are recorded in additional paid-in capital at issuance and are not subject to remeasurement. Liability-classified warrants are recorded at fair value at each reporting period with any change in fair value recognized as a component of change in fair value of warrants in the condensed consolidated statements of operations. The Company periodically evaluates changes in facts and circumstances that could impact the classification of warrants.

Available-for-Sale Securities

The Company’s available-for-sale securities consist of U.S. government and agency securities. Securities with maturities from the date of purchase of less than three months are included in cash equivalents. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed consolidated statements of operations and comprehensive income/loss and as a separate component of stockholders’ equity. Realized gains and losses are calculated on the specific identification method and recorded as interest income (loss). At each balance sheet date, the

Company assesses available-for-sale securities in an unrealized loss position to determine whether the decline in fair value below amortized cost is a result of credit losses or other factors, whether the Company expects to recover the amortized cost of the security, the Company’s intent to sell and if it is more likely than not that the Company will be required to sell the securities before the recovery of amortized cost. The Company records changes in allowance for expected credit loss in other income (expense). There has been no allowance for expected credit losses recorded during any of the periods presented.

Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Accretion of discounts are recorded in interest income in the condensed consolidated statements of operations and comprehensive income/loss.

During the three and nine months ended September 30, 2024, the unrealized gain on the Company’s available-for-sale securities was less than $1,000, and not presented separately in the condensed consolidated statement of operations.

Recently Issued Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (ASU) No. 2023-09 Income Taxes (Topic 740): Improvements to Income Tax Disclosure. This ASU includes amendments that further enhance income tax disclosures, primarily through standardization and disaggregation of rate reconciliation categories and income taxes paid by jurisdiction. The ASU is effective for years beginning after December 15, 2024, but early adoption is permitted. This ASU should be applied on a prospective basis, although retrospective application is permitted. Management is currently evaluating the impact of the changes required by the new standard on the Company’s consolidated financial statements and related disclosures.

In November 2023, the FASB issued Accounting Standard Update (ASU) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The new standard is intended to improve annual and interim reportable segment disclosure requirements regardless of number of reporting units, primarily through enhanced disclosures of significant expenses. The amendment requires public entities to disclose significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit and loss. This update is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years starting after December 15, 2024. This ASU must be applied retrospectively to all prior periods presented. Management is currently evaluating the impact of the changes required by the new standard on the Company’s consolidated financial statements and related disclosures.

2. Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions affecting the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period. The Company’s most significant estimates and critical accounting policies involve reviewing assets for impairment and determining the assumptions used in measuring stock-based compensation expense and warrant liability.

3. Liquidity and Going Concern

The Company incurred a net loss of $9.1 million for the nine months ended September 30, 2024. The Company had an accumulated deficit of$489.6 million as of September 30, 2024. Additionally, the Company used net cash of$9.3 million to fund its operating activities for the nine months ended September 30, 2024.

To date, the Company’s operating losses have been funded primarily from outside sources of invested capital from issuance of its common and preferred stocks, proceeds from its term loan, line of credit facility and grant funding. However, the Company has had, and will continue to have, an ongoing need to raise additional cash from outside sources to fund its future clinical development programs and other operations. There can be no assurance that the Company will be able to continue to raise additional capital in the future. The Company’s inability to raise additional cash would have a material and adverse impact on its operations and could cause the Company to default on its term loan. These factors raise substantial doubt about the Company’s ability to continue as a going concern.

At the closing of the May 2024 Private Placement (as defined below), the Company received aggregate up-front gross proceeds of approximately $7.3 million, before deducting fees and other expenses associated with the closing of the May 2024 Private Placement. None of the Series A and Series B Warrants issued in connection with May 2024 Private Placement were exercised as of September 30, 2024. See Note 12 to the unaudited condensed consolidated financial statements, Stockholders’ Deficit - May 2024 Private Placement, for further details.

Nasdaq Listing Compliance

On March 8, 2024, the Company received a written notice (the “Notice”) from the Listing Qualifications staff of The Nasdaq Stock Market LLC (“Nasdaq”), notifying the Company that it no longer complied with the requirement under Nasdaq Listing

Rule 5550(b)(1) to maintain a minimum of $2.5 million in stockholders’ equity (the “Minimum Stockholders’ Equity Requirement”) for continued listing on The Nasdaq Capital Market or the alternative requirements of having a market value of listed securities of $35 million or net income from continuing operations of $500,000 in the most recently completed fiscal year or two of the last three most recently completed fiscal years.

On September 5, 2024, Nasdaq notified the Company that it had not regained compliance with Nasdaq Listing Rule 5550(b)(1) and that, as a result, unless the Company timely requests an appeal of this determination to a Nasdaq Hearings Panel (the “Panel”), Nasdaq would move to suspend trading of the Company’s common stock and to have the Company’s shares of common stock delisted from The Nasdaq Capital Market. The Company timely requested a hearing before the Panel, and the hearing was held on October 22, 2024.

On October 30, 2024, the Company received a decision from the Panel, notifying the Company that it had until March 4, 2025, to demonstrate compliance with the Minimum Stockholders’ Equity Requirement. The Panel also required that the Company file a public disclosure on or before March 4, 2025 and describe the transactions undertaken by the Company to achieve compliance and demonstrate long-term compliance with the Minimum Stockholders’ Equity Requirement. The Panel also noted that it is a requirement during the exception period that the Company provides prompt notification to the Panel of any significant events that occur during this time that may affect the Company’s compliance with Nasdaq’s requirements. This includes, but is not limited to, any event that may call into question the Company’s ability to meet the terms of the exception granted. The Panel reserved the right to reconsider the terms of its decision based on any event, condition or circumstance that exists or develops that would, in the opinion of the Panel, make continued listing of the Company’s securities on The Nasdaq Capital Market inadvisable or unwarranted.

The Company continues to seek additional capital from financing alternatives and other sources in order to ensure adequate funding is available to allow the Company to continue research and product development and other operating activities at their current levels. 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 from outside sources, it would have a material adverse impact on its operations.

The accompanying condensed 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.

4. Fair Value Measurements

Fair value measurements are market-based measurements, not entity-specific measurements. Therefore, fair value measurements are determined based on the assumptions that market participants would use in pricing the asset or liability. The Company follows a three-level hierarchy to prioritize the inputs used in the valuation techniques to derive fair values. The basis for fair value measurements for each level within the hierarchy is described below:

•

Level 1: Quoted prices in active markets for identical assets or liabilities.

•

Level 2: Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets.

•

Level 3: Valuations derived from valuation techniques in which one or more significant inputs are unobservable in active markets.

Money market funds are valued at the closing price reported by the fund sponsor from an actively traded exchange. Money market funds were included in cash equivalents and U.S. Treasury bills were included in investments in the condensed consolidated balance sheets for the periods presented. The Company obtains the fair value of its Level 2 cash equivalents from third-party pricing services. The pricing services utilize industry standard valuation models whereby all significant inputs, including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, bids, offers, or other market-related data, are observable.

The following table summarizes the Company’s fair value hierarchy for its financial assets measured at fair value on a recurring basis as of September 30, 2024 and December 31, 2023, respectively (in thousands).

During the nine months ended September 30, 2024, the Company issued common stock warrants which were initially classified as liabilities under authoritative accounting standards, and reclassified in the equity section of the balance sheet upon modification in August 2024 (See Note 12, Stockholders’ Deficit - May 2024 Private Placement, for further details). These common stock warrants were valued using the Black Scholes model, with level 3 inputs such as expected volatility, risk-free interest rate, and expected term that are not observable in active markets.

The table below summarizes key inputs used in the valuation of the liability classified warrants as of the issuance date and as of the date of amendment:

The table below provides a summary of the fair value of the Company’s warrant liability during the nine months ended September 30, 2024 (in thousands). As of September 30, 2023, the fair value of liability classified warrants was immaterial, and the change in the fair value of liability classified warrants during the three and nine months ended September 30, 2023 was immaterial.

5. Term Loan Obligations

On May 29, 2015, the Company entered into the Loan and Security Agreement (the “Loan and Security Agreement”), pursuant to which Oxford Finance, LLC (“Oxford”) funded an aggregate principal amount of $17.7 million (the “Term Loan”), subject to the terms and conditions set forth in the Loan and Security Agreement.

Pursuant to the Loan and Security Agreement, as amended, the Company made interest only payments through May 1, 2021, and thereafter was required to make payments of principal and accrued interest in equal monthly installments sufficient to amortize the Term Loan through June 1, 2024, the maturity date. On June 3, 2024, the Company paid off the Term Loan by making a final payment in an aggregate amount equal to approximately $3.3 million, which included both the balance of outstanding principal and interest and the final payment fee due. The repayment in full of the Term Loan terminated Oxford’s security interest in the Company’s existing and after-acquired assets, as well as all other certain restrictions and covenants under the Term Loan.

6. Line of Credit Facility

On May 31, 2024, the Company drew down $3.3 million on a new margin loan facility under a line of credit (the “Pershing Credit Facility”) with Pershing LLC (“Pershing”), an affiliate of The Bank of New York Mellon Corporation. The available credit line limit under the Pershing Credit Facility fluctuates based on the Company’s request for extensions from time to time, subject to the value of the collateralized marketable securities the Company holds with Pershing, provided that the amount available to draw under the Pershing Credit Facility cannot exceed 91.5%of the value of the collateralized marketable securities deposited with Pershing. Depending on the value of the marketable securities the Company holds with Pershing, Pershing may require the

Company from time-to-time to deposit additional funds or marketable securities in order to restore the level of collateral to an acceptable level. The amounts borrowed under the Pershing Credit Facility are due on demand. As of September 30, 2024, the Company held collateralized marketable securities with Pershing with a total value of $3.6 million.

Borrowings under the Pershing Credit Facility bear interest at the target interest rate set by the Federal Open Market Committee, subject to a floor of 5.5%, plus a spread of 1.75% and applicable fees of 0.5%, subject to a maximum interest rate of the then applicable Prime Rate as published in The Wall Street Journal plus 3.0%. Interest payments thereunder are calculated on a monthly basis and, unless paid, are added to the outstanding balance under the Pershing Credit Facility. The proceeds under the Pershing Credit Facility are available for working capital needs and other general corporate purposes. Volatility in the global markets could cause the interest rate to fluctuate from time to time increasing the Company’s costs, or could cause Pershing to terminate the Company’s ability to borrow funds. In addition, borrowings under the Pershing Credit Facility have the effect of limiting the Company’s use of cash and marketable securities.

7. Loss per Share

Basic per share data is computed by dividing net income or loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Diluted per share data is computed by dividing net income or loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during the period increased to include, if dilutive, the number of additional shares of common stock that would have been outstanding as calculated using the treasury stock method. Potential common shares were related to outstanding but unexercised options, multiple series of convertible preferred stock, and warrants for all periods presented.

The Company considers Series A Warrants and Series B Warrants issued in connection with the private placement completed in May 2024 (See Note 12, Stockholders’ Deficit - May 2024 Private Placement, for further details) to be participating securities because holders of such instruments participate in the event a dividend is paid on shares of common stock. The holders of the Series A Warrants and Series B Warrants do not have a contractual obligation to share in the Company’s losses. As such, losses are attributed entirely to common stockholders and for periods in which the Company has reported a net loss.

As of September 30, 2024,979,715 Pre-Funded Warrants to purchase shares of common stock, issued in connection with the May 2024 Private Placement (See Note 12, Stockholders’ Deficit - May 2024 Private Placement, for further details), were included in the basic and diluted net loss per share calculation.

The following table sets forth the computation of basic and diluted net loss per share of common stock for the periods indicated, in thousands except share and per share data:

The following were excluded from the diluted loss per share calculation for the periods presented because their effect would be anti-dilutive:

8. Biocept Asset Acquisitions

On April 26, 2024, the Company, after having its bid accepted by the United States Bankruptcy Court for the District of Delaware, acquired from Biocept, for a total cash payment of $400,000, substantially all of the right, title and interest in acerebrospinal fluid cancer diagnostic portfolio (“CNSide®”), including (i) intellectual property, (ii) inventory and raw materials, and (iii) data, information, results and reports pertaining to the completed and on-going clinical studies involving the use of CNSide® (including, but not limited to, the FORESEE clinical study that was being conducted by Biocept), related to the development, making, selling, and exporting or importing of the CNSide® proprietary cell enumeration test (the “CNSide Test”).

The Company concluded that the acquisition of the Biocept assets was not a business combination, as Biocept did not meet the definition of a business in ASC 805, Business Combination. The Company accounted for the asset purchase transaction under the authoritative guidance for asset acquisitions, and allocated the costs of acquisitions of approximately $45,000 among the assets acquired based on the relative fair value of such assets, which is predominately concentrated in the intellectual property acquired including patents and trademarks. The intangible assets acquired from Biocept are capitalized and amortized over a useful life of four years.

9. Grant Revenue

CPRIT Grant

On September 19, 2022, the Company entered into that certain Cancer Research Grant Contract (the “CPRIT Contract”), effective as of August 31, 2022, with the Cancer Prevention and Research Institute of Texas (“CPRIT”), pursuant to which CPRIT provides the Company with a CPRIT grant (“CPRIT Grant”) over athree-year period to fund the continued development of rhenium (186 Re) obisbemeda for the treatment of patients with leptomeningeal metastases. The CPRIT Grant is subject to customary CPRIT funding conditions, including, but not limited to, a matching fund requirement (one dollar for every two dollars awarded by CPRIT), revenue sharing obligations upon commercialization of rhenium (186 Re) obisbemeda based on specific dollar thresholds and tiered low single digit royalty rates until CPRIT receives the aggregate amount of 400% of the proceeds awarded under the CPRIT Grant, and certain reporting requirements.

The CPRIT Contract will terminate on August 30, 2025, unless terminated earlier by (a) the mutual written consent of all parties to the CPRIT Contract, (b) CPRIT for an event of default by the Company, (c) CPRIT, if the funds allocated to the CPRIT Grant become legally unavailable during the term of the CPRIT Contract and CPRIT is unable to obtain additional funds for such purposes, and (d) the Company for convenience. CPRIT may require the Company to repay some or all of the disbursed CPRIT Grant proceeds (with interest not to exceed 5% annually) in the event of the early termination of the CPRIT Contract by CPRIT for an event of default by the Company or by the Company for convenience, or if the Company relocates its principal place of business outside of the state of Texas during the CPRIT Contract term or within three years after the final payment of the grant funds.

The Company retains ownership over any intellectual property developed under the CPRIT Contract (each, a “Project Result”). With respect to non-commercial use of any Project Result, the Company granted to CPRIT a nonexclusive, irrevocable, royalty-free, perpetual, worldwide license with right to sublicense any necessary additional intellectual property rights to exploit all Project Results by CPRIT, other governmental entities and agencies of the State of Texas, and private or independent institutions of higher education located in Texas, for education, research and other non-commercial purposes.

The Company recognized $1.5 million and $4.4 million, and $1.2 million and $3.6 million in grant revenue from the CPRIT Contract during the three and nine months ended September 30, 2024 and 2023, respectively.

Department of Defense Award

Effective September 1, 2024, the Company entered into an agreement with the Department of Defense office of the Congressionally Directed Medical Research Programs to receive a $3.0 million award for research and development purposes (“DoD Award”) over athree year period. The DoD Award will be used to support the planned expansion of the Company’s clinical trial for pediatric brain cancer. The Company expects that the work performed under the DoD Award and funding of the award to commence during the fourth quarter of 2024. As of September 30, 2024, no grant revenue has been recognized related to the DoD Award. On October 4, 2024, the Company received its first payment under the DoD Award in the amount of $0.9 million.

10. Commitments and Contingencies

Leases

The Company leases laboratory, office and storage facilities in San Antonio, Texas, under operating lease agreements that expire in 2025. The Company also leases certain office space in Austin, Texas under a month-to-month operating lease agreement and certain office space in Charlottesville, Virginia (the “Charlottesville Lease”). The Charlottesville Lease has a term of 12 months and the Company has the ability torenew for three additionalone-year periods. On March 31, 2023, Company believed that it was reasonably certain that the Charlottesville Lease will be renewed through March 31, 2026, and as a result, it remeasured the related lease liability as of March 31, 2023 to be $80,000 using the then-in-effect discount rate of 12.76%. Effective July 1, 2023, the Company added additional office lease premises in Charlottesville, which was accounted for as a separate operating lease contract with a lease liability and corresponding right-of-use asset of $19,000, as a discount rate of 13.47%.

Other commitments and contingencies

The Company has entered into agreements with various research organizations for pre-clinical and clinical development studies, which have provisions for cancellation. Under the terms of these agreements, the vendors provide a variety of services including conducting research, recruiting and enrolling patients, monitoring studies and data analysis. Payments under these agreements typically include fees for services and reimbursement of expenses. The timing of payments due under these agreements is estimated based on current study progress. As of September 30, 2024, the Company didnot have any clinical research study obligations.

Legal proceedings

From time to time, the Company is subject to legal proceedings and claims, whether asserted or unasserted, that arise in the ordinary course of business. Due to their nature, such legal proceedings involve inherent uncertainties including, but not limited to, court rulings, negotiations between affected parties and governmental actions. Management assesses the probability of loss for such contingencies and accrues a liability and/or discloses the relevant circumstances, as appropriate.

11. License Agreements

Biocept License Agreement

On September 7, 2023, the Company entered into a Non-Exclusive License and Services Agreement with Biocept, pursuant to which Biocept granted the Company a non-exclusive license to use the CNSide Test. In exchange for the license, the Company issued to Biocept 53,381 unregistered shares of common stock, the fair value of which was $75,000.

On October 16, 2023, Biocept filed a voluntary petition for relief under the provisions of Chapter 7 of Title 11 of the United States Bankruptcy Code. See Note 8, the Biocept Asset Acquisitions, for further details.

University of Texas Health Science Center at San Antonio (“UTHSCSA”) License Agreement

On December 31, 2021, the Company entered into a Patent and Know-How License Agreement with UTHSCSA, pursuant to which UTHSCSA granted the Company an irrevocable, perpetual, exclusive, fully paid-up license, with the right to sublicense and to make, develop, commercialize and otherwise exploit certain patents, know-how and technology related to the development of biodegradable alginate microspheres containing nanoliposomes loaded with imaging and/or therapeutic payloads.

NanoTx License Agreement

On March 29, 2020, the Company and NanoTx, Corp. (“NanoTx”) entered into a Patent and Know-How License Agreement, pursuant to which NanoTx granted the Company an irrevocable, perpetual, exclusive, fully paid-up license, with the right to sublicense and to make, develop, commercialize and otherwise exploit certain patents, know-how and technology related to the development of radiolabeled nanoliposomes.

The transaction terms included an upfront payment of $0.4 million in cash and $0.3 million in the Company’s shares of common stock. The transaction terms also included success-based milestone and royalty payments contingent on key clinical, regulatory and sales milestones, as well as the requirement to pay 15% of any non-dilutive monetary awards or grants received from external agencies to support product development of the nanoliposome encapsulated BMEDA-chelated radioisotope, which includes grants from CPRIT. As of September 30, 2024, the Company accrued $1.0 million of payments due to NanoTx as a result of the CPRIT grant received (see Note 9, Grant Revenue, for further details).

12. Stockholders’ Deficit

Preferred Stock

The Company has authorized 5,000,000 shares of preferred stock, par value $0.001 per share. The Company’s Board is authorized to designate the terms and conditions of any preferred stock the Company issues without further action by the common stockholders.

Series F Preferred Stock

On March 3, 2023, the Company filed a certificate of designation (the “Certificate of Designation”) with the Secretary of State of the State of Delaware, effective as of the time of filing, designating the rights, preferences, privileges and restrictions of the Series F Preferred Stock, with the total authorization of one (1) share of Series F Preferred Stock. The Certificate of Designation provided that the share of Series F Preferred Stock would have 50,000,000 votes per share of Series F Preferred Stock and would vote together with the Company’s common stock, as a single class exclusively with respect to any proposal to amend the Company’s certificate of incorporation to effect the reverse stock split. On March 3, 2023, the Company entered into a subscription and investment representation agreement with Richard J. Hawkins, chairman of the board of the Company, who is an accredited investor (the “Series F Preferred Stock Purchaser”), pursuant to which the Company agreed to issue and sell one (1) share of the Company’s Series F Preferred Stock, par value $0.001 per share, to the Series F Preferred Stock Purchaser for $1,000 in cash. The sale closed on March 3, 2023.

The outstanding share of Series F Preferred Stock was redeemed in whole, automatically effective upon the approval by the Company’s stockholders of the reverse stock split in April 2023. Upon such redemption, the Series F Preferred Stock Purchaser received consideration of $1,000 in cash.

On November 12, 2024, the Company filed a Certificate of Elimination (“Certificate of Elimination”) with the Secretary of State of the State of Delaware effecting the elimination of the Certificate of Designation relating to the Series F Preferred Stock. Following the filing of the Certificate of Elimination the previously-authorized share of the Series F Preferred Stock resumed the status of an undesignated share of the Company’s preferred stock.

Series B and C Preferred Stock

As of September 30, 2024, there were 938 outstanding shares of Series C Preferred Stock that can be converted into an aggregate of 27,792 shares of common stock, and 1,014 shares of Series B Convertible Preferred Stock that can be converted into an aggregate of 398 shares of common stock.

Common Stock

May 2024 Private Placement

On May 5, 2024, the Company entered into a securities purchase agreement (the “Securities Purchase Agreement”) with certain investors, including certain of the Company’s directors and executive officers (“Company Insiders”) (collectively, the “Purchasers”), for the sale and issuance by the Company of its securities (the “Initial Subscription”). On May 8, 2024, the Company entered into a first amendment to the Securities Purchase Agreement (together with the Securities Purchase Agreement, the “Purchase Agreement”), for the sale and issuance by the Company of additional securities to two of the Purchasers (the “Additional Subscription”, and together with the Initial Subscription, the “May 2024 Private Placement”). The Purchase Agreement provides for the sale and issuance by the Company of an aggregate of 3,591,532 shares (the “Private Placement Shares”) of the Company’s common stock or, at the election of each Purchaser, pre-funded warrants (the “Pre-Funded Warrants”), exercisable immediately at an exercise price of $0.001 per share, with each Private Placement Share or Pre-Funded Warrant accompanied by (i) a Series A common warrant (“Series A Warrants”) to purchase one share of common stock, for an aggregate of 3,591,532 Series A Warrants, and (ii) one Series B common warrant (“Series B Warrants”) to purchase one share of common stock, for an aggregate of 3,591,532 Series B Warrants.

The combined purchase price for each Private Placement Share and Pre-Funded Warrant from the Initial Subscription was $2.022, and $2.158 from the Additional Subscription, in each case together with one accompanying Series A Warrant and one accompanying Series B Warrant, provided, that the Company Insiders participated in the Initial Subscription at an offering price of $2.04 per Private Placement Share and accompanying Series A Warrant and Series B Warrant.

The exercise price of Series A Warrants and Series B Warrants from the Initial Subscription is $1.772 per share and $1.908 per share in the Additional Subscription, provided that the exercise price for the Series A Warrants and Series B Warrants issued to the Company Insiders is $1.79 per share. Subject to certain ownership limitations, the Series A Warrants will be exercisable until May 9, 2029, which is the five-year anniversary of issuance. Subject to certain ownership limitations, the Series B Warrants will be exercisable until June 24, 2025. The Pre-Funded Warrant will not expire until exercised in full.

Prior to the Amendment and Restatements (as defined below), if a holder of a Series A Warrant or a Series B Warrant was unable to exercise the warrant due to the limitation contained in the warrant that restricts the holder from owning above a specified beneficial ownership level (generally 4.99% or 9.99%) as the result of exercise of the warrant, then the holder had the right to elect upon exercise of the warrant to receive a Pre-Funded Warrant for the same number of shares of common stock that would otherwise have been received upon exercise of the warrant. In addition, prior to the Amendment and Restatements, the Series A Warrants and Series B Warrants provided for a call right starting June 24, 2025, in favor of the Company, if the volume-weighted average price of the shares of common stock exceeds specified prices.

The May 2024 Private Offering closed on May 9, 2024. The Company issued 2,151,544 Pre-Funded Warrants,3,591,532 Series A Warrants and 3,591,532 Series B Warrants to purchase shares of its common stock in connection with the May 2024 Private Placement. The aggregate gross proceeds from the May 2024 Private Placement were approximately $7.3 million, before deducting $0.4 million of offering expenses.

The Company reviewed the terms of the Pre-Funded Warrants, Series A Warrants and Series B Warrants under the authoritative accounting guidance as of the issuance date.

As described above, the Series A Warrants and Series B Warrants were initially classified as liabilities for the reason that they could have been exercised into either shares of common stock or Pre-Funded Warrants at the holder’s option and thus failed the indexation guidance under ASC 815, Derivatives and Hedging. The Series A Warrant and Series B Warrant liability were initially recorded at fair value as of the issuance date, and under the terms of the Series A Warrants and Series B Warrants when issued that liability was subject to adjustment to estimated fair value at each balance sheet date until the warrants were settled. Refer below for additional information regarding the amendment of the Series A Warrants and Series B Warrants that eliminated the ability of the Series A Warrants and Series B Warrants to be exercised into Pre-Funded Warrants, and as a result, the reclassification of the Series A and B Warrants from liability to equity section of the condensed consolidated balance sheet.

The Pre-Funded Warrants are equity classified because they (1) are freestanding financial instruments that are legally detachable and separately exercisable from the common stock, (2) are immediately exercisable, (3) do not embody an obligation for the Company to repurchase its shares, (4) permit the holder to receive a fixed number of shares of common stock upon exercise, (5) are indexed to the Company’s common stock and (6) meet the equity classification criteria.

The proceeds from the May 2024 Private Placement were first allocated to the full fair value of the Series A Warrants and Series B Warrants due to the initial liability classification. As disclosed in Note 4, Fair Value Measurements, the fair value of the Series A Warrants and Series B Warrants at issuance was $10.9 million. Under authoritative guidance, if the fair value of a warrant liability exceeds the proceeds received in an arm’s length transaction with no rights or privileges that require separate accounting recognition as an asset identified, then the warrant liability is recorded at fair value with the excess of fair value over proceeds recognized as a loss in earnings. The Company recognized approximately $3.5 million in financing expense in the condensed consolidated statement of operations during the nine months ended September 30, 2024, which represents the excess of the fair value of the Series A Warrants and Series B Warrants at issuance over the proceeds. During the three and nine months ended September 30, 2024, the Company recognized a fair value gain on warrant liability of $1.0 and $5.7 million, respectively. Proceeds from the May 2024 Private Placement are shown as cash from financing transactions and the gain on warrant liability is included as an adjustment to reconcile the net loss to net cash used in operating activities in the statements of cash flows for the nine months ended September 30, 2024.

In addition, total offering expenses related to the May 2024 Private Placement of $0.4 million were recorded as a component of other expenses as the entire proceeds were allocated to the warrant liability, which, prior to the amendment described below, could be settled with either the Company’s shares of common stock or Pre-Funded Warrants, which are exercisable into the Company’s shares of common stock at any time at the holders’ option, but not in cash payment to the holders.

As of September 30, 2024, all of the Series A Warrants, and Series B Warrants issued in connection with the May 2024 Private Placement remained outstanding, and Pre-Funded Warrants to purchase 1,959,430 shares of the Company’s common stock remained outstanding.

Amendment and Restatement of Series A Warrants and Series B Warrants

On August 9, 2024, the Company amended and restated the Series A Warrants and Series B Warrants (the “Amendment and Restatements”) issued in the May 2024 Private Placement. The Amendment and Restatements eliminated the ability of the holders of the Series A Warrants and Series B Warrants to elect to purchase Pre-Funded Warrants upon exercise of the Series A Warrants and Series B Warrants in lieu of shares of common stock if the holder would have been restricted because of the specified beneficial ownership level in the Series A Warrants and Series B Warrants.

In addition, the Amendment and Restatements eliminated the Company’s call right under the terms of the Series A Warrants to call the Series A Warrants after June 24, 2025, if the volume-weighted average price of shares of common stock exceeded specified prices. There were no other changes in the terms of the Series A Warrants and Series B Warrants.

As a result of the Amendment and Restatements, the Series A Warrants and Series B Warrants, as amended, no longer fail the indexation guidance under ASC 815, Derivatives and Hedging, and the fair value of the warrant liability at the amendment date, in the amount of $5.2 million, was reclassified to equity.

Lincoln Park Purchase Agreement

On August 2, 2022, the Company entered into a purchase agreement (the “2022 Purchase Agreement”) and registration rights agreement pursuant to which Lincoln Park Capital Fund (“Lincoln Park”) committed to purchase up to $50.0 million of the Company’s common stock. Under the terms and subject to the conditions of the 2022 Purchase Agreement, the Company has the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park is obligated to purchase up to $50.0 million of the Company’s common stock. Such sales of common stock by the Company are subject to certain limitations, and can occur from time to time, at the Company’s sole discretion, over the 36-month period commencing on August 17, 2022, subject to the satisfaction of certain conditions.

On May 16, 2022, the Company received stockholder approval for purposes of the Nasdaq listing rules to permit issuances of up to 57.5 million shares of the Company’s common stock (including the issuance of more than 19.99% of the Company’s common stock) to Lincoln Park, and it was pursuant to that approval that the Company entered into the 2022 Purchase Agreement.

Upon execution of the 2022 Purchase Agreement, the Company paid $0.1 million in cash as the initial commitment fee, and issued 32,846 shares as the initial commitment shares, to Lincoln Park as consideration for its irrevocable commitment to purchase shares of the Company’s common stock at its direction under the 2022 Purchase Agreement. The Company has agreed to pay an additional commitment fee, which it may elect to pay in cash or shares of its common stock, or a combination of cash and shares of its common stock, upon receipt of $25.0 million aggregate gross proceeds from sales of common stock to Lincoln Park under the 2022 Purchase Agreement.

On August 17, 2022, a registration statement (the “First Registration Statement”) was declared effective to cover the resale of up to 633,333 shares of the Company’s common stock comprised of (i) the 32,846 initial commitment shares, and (ii) up to 600,486 that the Company has reserved for issuance and sale to Lincoln Park under the 2022 Purchase Agreement from time to time from and after the date of the prospectus. The Company sold 527,166 shares of common stock to Lincoln Park in connection with the First Registration Statement.

On August 18, 2023, a second registration statement (the “Second Registration Statement”) was declared effective to cover the resale of up to an additional 1,500,000 shares of the Company’s common stock that the Company reserved for issuance and sale to Lincoln Park under the 2022 Purchase Agreement from time to time. The Company sold 150,000 shares of common stock to Lincoln Park in connection with the Second Registration Statement. The Company cannot sell more shares than registered under the Second Registration Statement under the 2022 Purchase Agreement without registering additional shares.

Actual sales of shares of common stock to Lincoln Park under the 2022 Purchase Agreement depend on a variety of factors to be determined by the Company from time to time, including, among others, market conditions, the trading price of the common stock and determinations by the Company as to the appropriate sources of funding for the Company and its operations. The net proceeds under the 2022 Purchase Agreement to the Company depend on the frequency and prices at which the Company sells shares of its common stock to Lincoln Park.

During the period from August 17, 2022 to December 31, 2022, the Company issued 266,666 shares of common stock under the 2022 Purchase Agreement for net proceeds of approximately $3.2 million. The Company issued 410,500 shares of common stock under the 2022 Purchase Agreement for net proceeds of approximately $1.0 million from January 1, 2023 to December 31, 2023. The Company didnot issue any shares of common stock under the 2022 Purchase Agreement during the nine months ended September 30, 2024.

Share Repurchase Program and Treasury Stock

On October 31, 2023, the Company announced that its Board has approved a share repurchase program (the “Share Repurchase Program”), with authorization to repurchase up to $500,000 of the outstanding shares of the Company’s common stock. The Company funded repurchases under the Share Repurchase Program with available cash.

During the year ended December 31, 2023, the Company purchased 78,559 shares of its common stock for approximately $0.1 million as treasury stock. The Company purchased 179,866 shares of its common stock for approximately $0.4 million as treasury stock during the nine months ended September 30, 2024. As of September 30, 2024, no amount remained authorized for repurchase.

13. Stock-based Compensation

Under the Company’s 2015 New Employee Incentive Plan, as amended (the “2015 Plan”), awards may only be granted to employees who were not previously an employee or director of the Company, or following a bona fide period of non-employment, as a material inducement to entering into employment with the Company. On June 6, 2024, the Company’s Board increased the number of shares for future issuances under the 2015 Plan by 75,000 shares of common stock. As of September 30, 2024, there were 62,908 shares of common stock remaining and available for future issuances under the 2015 Plan.

The Company’s 2020 Stock Incentive Plan, as amended and restated (the “2020 Plan”), which replaced the Company’s 2014 Equity Incentive Plan, provides for the award or sale of shares of common stock (including restricted stock), the award of stock units and stock appreciation rights, and the grant of both incentive stock options to purchase common stock to directors, officers, employees and consultants of the Company. The 2020 Plan provides for the issuance of up to 1,236,667 shares of common stock, including an increase of 1,000,000 shares as approved by the Company’s stockholders at the Company’s 2024 annual stockholders’ meeting during the three months ended September 30, 2024, plus the number of shares of common stock available for issuance is increased to the extent that awards granted under the 2020 Plan and the Company’s 2014 Equity Incentive Plan are forfeited or expire (except as otherwise provided in the 2020 Plan). As of September 30, 2024, there were 692,596 shares remaining and available for future issuances under the 2020 Plan.

Generally, options issued under the 2020 Plan are subject to atwo-yearor four-year vesting schedule with 25% of the options vesting on the one year anniversary of the grant date followed by equal monthly installment vesting, and have a contractual term of 10 years.

A summary of activity for the nine months ended September 30, 2024 is as follows:

As of September 30, 2024, the total compensation cost related to non-vested stock options not yet recognized for all the Company’s plans is approximately $0.8 million, which is expected to be recognized as a result of vesting under service conditions over a weighted average period of 2.8 years.