PLUS THERAPEUTICS, INC.

September 30, 2025

1. Organization and Basis of Presentation

Description of Business

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.

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements for the three and nine months ended September 30, 2025 and 2024 have been prepared in accordance with accounting principles generally accepted in the United States of America ("US GAAP") for interim financial information. Accordingly, they do not include all of the information and footnotes required by US GAAP for annual financial statements. The condensed consolidated balance sheet at December 31, 2024 has been derived from the audited consolidated financial statements at December 31, 2024, but does not include all of the information and footnotes required by US GAAP for complete financial statements. 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 have been included. Operating results for the three and nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for the year ending December 31, 2025.

2. Summary of Significant Accounting Policies

Significant Accounting Policies

The Company’s significant accounting policies are disclosed in its Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC and have not materially changed during the nine months ended September 30, 2025. The Company believes that the disclosures provided here are adequate to make the information presented not misleading when these unaudited condensed consolidated financial statements are read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, filed with the Securities and Exchange Commission on March 31, 2025.

Use of Estimates

The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions affecting the financial statements and the accompanying notes. The Company’s most significant estimates and critical accounting policies involve estimating the fair value of its derivative instruments, reviewing assets for impairment and determining the assumptions used in measuring stock-based compensation expense.

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 ("IAS 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. Grant receivable represents grant funds not yet received for which the allowable expenses have 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 derivative liabilities 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 and bonds. 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) and as a separate component of stockholders’ equity. Realized gains and losses are calculated on the specific identification method and recorded as interest income (expense). 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.

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. The Company adopted this ASU as of January 1, 2025 which did not have a material impact on the Company’s consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03 Income Statement (Topic 220): Reporting Comprehensive Income - Expense Disaggregation Disclosures, which requires an entity to disclose on an annual and interim basis, disaggregated information about specific income statement expense categories. The guidance should be applied prospectively with the option to apply the standard retrospectively. The standard becomes effective for the annual period starting on January 1, 2027 and interim periods starting on January 1, 2028. The Company is in the process of analyzing the impact that the adoption of ASU 2024-03 will have on its disclosures.

3. Liquidity and Going Concern

The Company incurred a net loss of$16.7 million for the nine months ended September 30, 2025. The Company had an accumulated deficit of$510.2 million as of September 30, 2025. Additionally, the Company used net cash of$14.5 million to fund its operating activities for the nine months ended September 30, 2025.

To date, the Company’s operating losses have been funded primarily from outside sources of invested capital from issuance of its common stock, preferred stock, convertible notes and warrants, proceeds from its term loan, line of credit 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, launch the CNSide Test, and fund 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. These factors raise substantial doubt about the Company’s ability to continue as a going concern.

As disclosed in more detail in Note 13, the Company has entered into various financing agreements and raised capital by issuing convertible notes, its common stock, preferred stock and warrants to purchase its common stock.

Nasdaq Listing Compliance

On March 8, 2024, the Company received a written notice (the “Notice”) from the Listing Qualifications staff (the “Staff”) of The Nasdaq Stock Market LLC (the “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). The Company requested a hearing before the Nasdaq hearing panel, and 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.

On March 7, 2025, the Company received notification from Nasdaq that it had regained compliance with the Minimum Stockholders’ Equity Requirement.

Pursuant to Nasdaq Listing Rule 5815(d)(4)(B), the Company is subject to a Mandatory Panel Monitor until March 7, 2026. If the Staff finds the Company again out of compliance with the Minimum Stockholders’ Equity Requirement before that date, the Company would not be permitted to provide the Staff with a plan of compliance with respect to that deficiency and the Staff would not be permitted to grant additional time for the Company to regain compliance with respect to that deficiency, nor would the Company be afforded an applicable cure or compliance period. Instead, the Staff would issue a “Delist Determination Letter” and the Company would have an opportunity to request a Nasdaq hearing panel regarding its continued listing.

Furthermore, on May 16, 2025, the Company received notice from 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 Minimum Bid Requirement notice has no immediate effect on the listing or trading of the Company’s common stock. Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the Company is 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 the Company’s common stock must meet or exceed $1.00 per share for a minimum of 10 consecutive business days prior to November 12, 2025.

If the Company does not achieve compliance with the Minimum Bid Requirement by November 12, 2025, the Company may be eligible for an additional 180 calendar days to regain compliance. To qualify, the Company would be required to meet the continued listing requirement for market value of publicly held shares and all other Nasdaq initial listing standards, with the exception of the Minimum Bid Requirement, and provide written notice of its intention to cure the minimum bid price deficiency during the second compliance period by effecting a reverse stock split if necessary. If the Staff determines that the Company will not be able to cure the deficiency, or if the Company is otherwise not eligible for such additional compliance period, Nasdaq will provide notice that the Company’s common stock will be subject to delisting. In the event the Company receives notice that its common stock is being delisted, Nasdaq rules permit the Company to appeal any delisting determination by the Staff.

On May 2, 2025, the stockholders granted discretionary authority to the Company’s board of directors to (i) amend the Company’s Certificate of Incorporation to combine outstanding shares of the Company’s common stock into a lesser number of outstanding shares, or a “reverse stock split,” at a specific ratio within a range ofone-for twenty five (1-for-25) to a maximum ofone-for-two hundred fifty (1-for-250), with the exact ratio to be determined by the board of directors in its sole discretion; and (ii) effect the reverse stock split, if at all, within twelve (12) months of the date the proposal is approved by stockholders.

In addition, on August 7, 2025, the stockholders granted discretionary authority to the Company’s board of directors to (i) amend the Company’s Certificate of Incorporation to combine outstanding shares of the Company’s common stock into a lesser number of outstanding shares, or a “reverse stock split,” at a specific ratio within a range of one-for two (1-for-2) to a maximum of one-for-two hundred fifty (1-for-250), with the exact ratio to be determined by the board of directors in its sole discretion; and (ii) effect the reverse stock split, if at all, within twelve (12) months of the date the proposal is approved by stockholders.

On June 3, 2025, the Staff notified the Company that it was not in compliance with the Minimum Stockholders’ Equity Requirement (the “June 3 Letter”). The Company reported stockholders’ equity (deficit) of ($23,641,000) in its Quarterly Report on Form 10-Q for the period ended March 31, 2025, and, as a result, did not satisfy the Minimum Stockholders’ Equity Requirement pursuant to Listing Rule 5550(b)(1). As a result, the Staff determined to delist the Company’s securities from Nasdaq, unless the Company timely requests an appeal of the Staff’s determination to a Hearings Panel (the “Panel”), pursuant to the procedures set forth in the Nasdaq Listing Rule 5800 Series. The Company must request a hearing no later than 4:00 p.m. Eastern Time on June 10, 2025. The Company timely requested a hearing, which hearing took place as scheduled on July 15, 2025.

On July 22, 2025, the Panel issued a decision (the “July 2025 Decision”) granting the Company’s request for continued listing on Nasdaq, subject to the Company demonstrating compliance with (1) the Minimum Stockholders’ Equity Requirement pursuant to Listing Rule 5550 (b)(1) by August 14, 2025 by filing a timely public disclosure describing the transactions undertaken by the Company to achieve compliance and demonstrate long-term compliance of the Minimum Stockholders’ Equity Requirement, and by providing an indication of its equity following those transactions, with the option by including in the public filing a balance sheet not older than 60 days with pro forma adjustments for any significant transactions or events occurring on or before the report date; and (2) the Minimum Bid Requirement 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) the Market Value of Listing Securities standard under 5550(b)(2), which requires certain companies to maintain a market value of listed securities of at least $35 million as well as compliance with (2) the alternative stockholders’ equity threshold under 5550(b)(1) or the Minimum Stockholders’ Equity Requirement. Accordingly, the Company satisfied two alternative criteria under

Nasdaq Listing Rule 5550.

As a result of such compliance, Nasdaq permitted the Company the remainder of the previously announced grace period to regain compliance with the $1.00 bid price rule under Nasdaq Listing Rule 5550(a)(2), through November 12, 2025. Nasdaq previously required that the Company remedy the bid price deficiency by September 8, 2025, a deadline that no longer applies.

The August 2025 Letter also provided that, solely with respect to the Equity Standard, the Company remains 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 Equity Standard (and the Company is not then in compliance with one of the alternative standards under Rule 5550(b)), the Company 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 Equity Standard nor will the Company be afforded an applicable cure or compliance period. Instead, the Staff will issue a delist determination letter, and the Company 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.

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 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:

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

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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.

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

Assets recorded at fair value

The Company has investments in money market accounts which are included in cash and cash equivalents and investments, respectively, on the condensed consolidated balance sheets. Money market accounts are considered Level 1 measurements within the fair value hierarchy since money market account fair values are known and observable through daily published floating net asset values.

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, 2025 and December 31, 2024, respectively (in thousands):

Liabilities recorded at fair value

Convertible Notes

As detailed in Note 13 below, the Company elected to account for convertible notes (consisting of funding notes and exchange notes) issued on February 13, 2025 at fair value as of the issuance date and immediately before their settlement date of March 4, 2025. The convertible notes are valued using the binomial lattice model with the following key level 3 inputs:

The following table provides a roll forward of the fair value of the convertible notes during thenine months ended September 30, 2025 (in thousands):

Warrants

As detailed in Note 13 below, the Company issued March 2025 Series A and March 2025 Series B common stock warrants in connection with the March 2025 Private Placement. The March 2025 Series A and March 2025 Series B common stock warrants are accounted for as liabilities at fair value at issuance date, and immediately prior to their extinguishment and modification, respectively, on June 17, 2025. The March 2025 Series A and March 2025 Series B common stock warrants were valued using the Monte Carlo simulation, with the following key level 3 inputs:

The March 2025 Series B Warrants were valued immediately prior to exercise, using the Monte Carlo simulation with the following inputs for the exercises that occurred before the modification on June 17, 2025:

In addition, the February 2025 Warrants issued in connection with the Funding Notes were required to be classified as liabilities and recorded at fair value. The Company estimated the fair value of the February 2025 Warrants using the Black Scholes model at issuance as of February 13, 2025 and as of their redemption date of March 4, 2025, using the following level 3 inputs:

The following table provides a roll forward of the fair value of liability classified common stock warrants during thenine months ended September 30, 2025 (in thousands):

5. Short-Term Investments

The Company classified short-term investments as available-for-sale securities, as the sale of such investments may be required prior to maturity to facilitate the execution of management strategies. During the three and nine months ended September 30, 2025, the unrealized gain on the Company's available-for-sale securities was immaterial, and not presented separately in the condensed consolidated statements of operations.

The Company classified all investments with maturities longer than three months from the date of purchase as short-term investments in the condensed consolidated balance sheets, reflecting its intent and ability to use these assets to meet the liquidity requirements of current operations. The following table summarizes contractual maturities of available-for-sale securities as of September 30, 2025 (in thousands):

6. 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 common shares 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 common shares outstanding during the period increased to include, if dilutive, the number of additional common shares that would have been outstanding as calculated using the treasury stock or if-converted method, as applicable. The Pre-Funded Warrants were included in the weighted average shares outstanding calculation (as of the beginning of the period or the date of the grant, whichever was earlier) for basic and dilutive earnings per share given their nominal exercise price.

The March 2025 Series A Warrants and March 2025 Series B Warrants (and for the period in which the February 2025 Warrants, Funding Notes, and Exchange Notes, as defined in Note 13, were outstanding) were participating securities because holders of such instruments would participate in the event a dividend is paid on common stock, however such holders did not have a contractual obligation to share in the Company’s losses. As such, losses were attributed entirely to common stockholders.

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 table provides a summary of instruments where underlying shares issuable upon exercise or conversion were excluded from the diluted loss per share calculation for the periods presented because their effect would be anti-dilutive. Additionally, the shares underlying the February 2025 Warrants, Funding Notes and Exchange Notes, each outstanding during thenine months ended September 30, 2025, were excluded from diluted loss per share as their effect would be anti-dilutive.

7. 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 REYOBIQTM 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 REYOBIQ 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 February 28, 2026, 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$1.4 million and$3.8 million, and$1.5 million and$4.4 million in grant revenue from the CPRIT Contract during the three and nine months ended September 30, 2025 and 2024, respectively. As of September 30, 2025 and December 31, 2024, the Company hadnil and $0.6 million, respectively, of grant revenue receivable related to the CPRIT Grant. As of September 30, 2025 and December 31, 2024, the Company had $1.1 million andnil of deferred grant liability related to the CPRIT Grant.

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. On October 4, 2024, the Company received its first payment under the DoD Award in the amount of $0.9 million, which was recorded as deferred grant liability as of September 30, 2025 and December 31, 2024. As of September 30, 2025 and December 31, 2024, no amount of grant revenue was recognized related to the DoD Award.

8. Commitments and Contingencies

Leases

The Company leases certain office space in Charlottesville, Virginia (the “Charlottesville Lease”). The Charlottesville Lease expires on March 31, 2026.

Manufacturing Agreement with SpectronRx

On November 5, 2024, the Company entered into a manufacturing services agreement with SpectronRx for drug product development and manufacturing, which includes an initial commitment fee of $0.3 million. Under this agreement, the Company owns all rights to intellectual property related to the products developed, while SpectronRx retains rights to its own technology. SpectronRx is required to negotiate a commercial supply agreement upon six months' written notice before the Company's first commercial manufacturing needs. The agreement will remain in place for five years, automatically renewing for successive one-year terms unless terminated with six months' notice. During the nine months ended September 30, 2025 and year ended December 31, 2024, the Company did not recognize any expenses related to this agreement.

Other commitments and contingencies

The Company has entered into agreements with various research organizations for preclinical 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 study progress. As of September 30, 2025, the Company didnot have any clinical research study obligations.

The Company has entered into service and subscription-based agreements, which are recorded in accounts payable and accrued expenses, with an offsetting amount included in deferred costs within other current assets.

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.

9. Composition of Certain Financial Statement Captions

As of September 30, 2025 and December 31, 2024, other current assets were comprised of the following (in thousands):

10. Line of Credit Facility

On May 31, 2024, the Company drew down $3.3 million on a 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 fluctuated 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 held with Pershing, Pershing could have required 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 were due on demand. As of September 30, 2025 and December 31, 2024, the Company held collateralized marketable securities with Pershing with a total value ofzero and $3.5 million, respectively.

Borrowings under the Pershing Credit Facility bore interest at the target interest rate set by the Federal Open Market Committee, subjectto 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 were calculated on a monthly basis and, unless paid, were 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.

On January 3, 2025, the Pershing Credit Facility was fully repaid and the collateralized marketable securities were fully redeemed.

11. License Agreements

UT Health Science Center at San Antonio (“UTHSCSA”) License Agreement

On December 31, 2021, the Company entered into a Patent and Know-How License Agreement (the “UTHSCSA License Agreement”) with The University of Texas Health Science Center at San Antonio (“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 (“BAM”) 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 voting 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, 2025, the Company accrued$0.3 million of payments due to NanoTx as a result of the CPRIT Grant proceeds received (see Note 7, Grant Revenue of the condensed consolidated financial statements for additional information).

12. Biocept Asset Acquisition

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, Inc. (“Biocept”), for a total cash payment of $400,000, substantially all of the right, title and interest in acerebrospinal fluid cancer diagnostic portfolio (the “CNSide® Platform”), 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 the CNSide Platform (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 acquisition 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.

13. Stockholders’ Equity

Preferred Stock

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

Series B and C Preferred Stock

As of September 30, 2025, 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

February 2025 SPEA Agreements

On February 13, 2025 (the “February 2025 Closing Date”), the Company entered into a Securities Purchase and Exchange Agreement (the “February 2025 SPEA”) with certain existing accredited investors (the “February 2025 Purchasers”). Pursuant to the February 2025 SPEA, on the February 2025 Closing Date the Company issued secured convertible promissory notes (the “Funding Notes”) in the aggregate principal amount of $3.3 million together with common stock purchase warrants (the “February 2025 Warrants”) to purchase 3,002,009 shares of the Company common stock, par value $0.001 and exercise price of $1.12 per share (the “February 2025 Warrant Exercise Price”). The aggregate purchase price for the Funding Notes and the February 2025 Warrants was approximately $3.7 million (the “Aggregate Purchase Price”) and included proceeds from the February 2025 Purchasers of $0.125 per February 2025 Warrant in accordance with Nasdaq listing rules. The Funding Notes would mature on February 13, 2026, and bore interest at a rate of 10% per annum, subject to increase upon events of default. The February 2025 Warrants were exercisable for five-years from the date of issuance.

The Funding Notes, accrued interest and February 2025 warrants were repurchased by the Company subsequent to consummation of the March 2025 Private Placement for proceeds of $4.2 million.

Security Interest

The obligations of the Company under the February 2025 SPEA, Funding Notes and Exchange Notes (as defined below) were secured by a pledge of substantially all of the assets of the Company pursuant to a security agreement, dated as of the February 2025 Closing Date, among the Company, CNSide Diagnostics, LLC (a subsidiary of the Company, “CNSide Diagnostics”), and Iroquois Master Fund Ltd., as collateral agent for the February 2025 Purchasers (the “Security Agreement”), subject to certain exceptions. The Security Agreement contained certain customary affirmative and negative covenants, including limitations on the Company’s and CNSide Diagnostic’s ability to dispose of assets, subject to customary exceptions. The repayment of the Company’s obligations under the February 2025 SPEA and Notes were guaranteed pursuant to a subsidiary guarantee, dated as of the February 2025 Closing Date (the “Subsidiary Guarantee”), by and among CNSide Diagnostics and the February 2025 Purchasers. The Security Agreement and the Subsidiary Guarantee were subsequently terminated after the closing of the private placement pursuant to the March 2025 SPA (as defined below).

Exchange Notes

As disclosed below, the Company entered into the May 2024 Purchase Agreement (defined below), with the May 2024 Purchasers for the private placement of securities, including the May 2024 Series A Warrants to purchase an aggregate of up to 3,591,532 shares of common stock. The May 2024 Purchase Agreement included certain limitations and restrictions on the Company’s ability to issue securities and provided the May 2024 Purchasers and the other investors signatories to the May 2024 Purchase Agreement participation rights in future equity and equity-linked offerings of securities, subject to certain limited exceptions (the “Financing Restrictions”). On the February 2025 Closing Date, pursuant to the February 2025 SPEA, the Company issued to the May 2024 Purchasers secured convertible promissory notes in the aggregate amount of $3.2 million (the “Exchange Notes”) in exchange for cancellation of the May 2024 Series A Warrants held by the May 2024 Purchasers, and the May 2024 Purchasers entered into a second amendment to the May 2024 Purchase Agreement to eliminate the Financing Restrictions. The terms and conditions of the Exchange Notes were substantially identical in all material respects to the Funding Notes. The Security Agreement and Subsidiary Guarantee also applied to the obligations under the Exchange Notes. The Exchange Notes were exchanged after the closing of the March 2025 Private Placement as defined below.

Both the Funding Notes and the Exchange Notes contained embedded conversion features that were required to be bifurcated and accounted for as derivative liabilities. The Company evaluated authoritative guidance for accounting for convertible debt instruments and elected to account for the Funding Notes and Exchange Notes at fair value. Consequently, the Company recorded the Funding Notes and Exchange Notes in their entirety at fair value at issuance and immediately before settlement, with changes in fair value recorded as change in fair value of derivative instruments in the condensed consolidated statements of operations between the issuance date and the settlement date.

The Company entered into the transaction due to immediate funding requirements. 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 Exchange Notes, Funding Notes and associated warrants were recorded at fair value on the issuance date at $3.8 million, $4.0 million and $2.7 million, respectively. The excess of the fair value of the instruments issued over cash received of $3.7 million and the carrying value of the May 2024 Series A Warrants exchanged of $3.7 million, in the amount of $3.1 million was recorded as a financing expense in the statement of operations for thenine months ended September 30, 2025.

Changes in the fair value of Exchange Notes, Funding Notes and February 2025 Warrants between issuance date and settlement date, in the amount of a gain of $0.3 million, a gain of $0.3 million and a gain of $2.2 million, respectively, were recorded as change in the fair value of derivative instruments in the statement of operations for the nine months ended September 30, 2025.

March 2025 Private Placement

On March 4, 2025, the Company entered into a securities purchase agreement (the “March 2025 SPA”) with accredited investors, including certain existing stockholders of the Company (collectively, the “March 2025 Private Placement Purchasers”) for a private placement of securities (the “March 2025 Private Placement”). The March 2025 SPA, provided for the sale and issuance bythe Company of an aggregate of 28,042,140 shares (the “March 2025 Private Placement Shares”) of the Company’s common stock, or, at the election of each March 2025 Private Placement Purchaser, pre-funded warrants to purchase Common Stock (the “March 2025 Pre-Funded Warrants”), exercisable immediately at an exercise price of $0.001 per share (the “March 2025 Pre-Funded Warrant Shares”), with each March 2025 Private Placement Share or March 2025 Pre-Funded Warrant accompanied by (i) a Series A common warrant (the “March 2025 Series A Warrants”) to purchase one share of common stock (the “March 2025 Series A Warrant Shares”), and (ii) one Series B common warrant (the “March 2025 Series B Warrants”) to purchase one share of common stock (see below for additional details on the Series B Warrants cashless exercise provisions) (the “March 2025 Series B Warrant Shares,” and together with the March 2025 Series A Warrant Shares, the “March 2025 Common Warrant Shares”). The March 2025 Private Placement Shares, March 2025 Pre-Funded Warrants, March 2025 Pre-Funded Warrant Shares, March 2025 Series A Warrants, March 2025 Series B Warrants, and the March 2025 Common Warrant Shares are collectively referred to herein as the “March 2025 Securities.” Pursuant to the March 2025 SPA, the Company issued to the March 2025 Private Placement Purchasers 4,069,738 March 2025 Private Placement Shares,23,972,400 March 2025 Pre-Funded Warrants,28,042,138 March 2025 Series A Warrants and 28,042,138 March 2025 Series B Warrants. As of September 30, 2025, all March 2025 Series A Warrants and March 2025 Series B Warrants were settled as a result of cancellation, exchanges or exercises as detailed below, and 2,611,809 March 2025 Pre-Funded Warrants remained outstanding.

The combined purchase price of $0.66 for each March 2025 Private Placement Share or $0.659 for each March 2025 Pre-Funded Warrant in the March 2025 Private Placement, together with one accompanying March 2025 Series A Warrant and one accompanying March 2025 Series B Warrant, represents the applicable “Minimum Price” in accordance with Nasdaq Rule 5635(d).

The initial exercise price of each March 2025 Series A Warrant issued in the March 2025 Private Placement was $1.32 per share of common stock. The March 2025 Series A Warrants were exercisable only following stockholder approval and expire five (5) years thereafter. The March 2025 Series A Warrants were subject to certain price reset, share combination event and anti-dilution provisions which, if triggered, provided that the number of shares issuable upon exercise of the March 2025 Series A Warrants would downward adjust, subject to a floor price of $0.132 (the “Floor Price”), and the number of shares issuable upon exercise therefor would increase such that the aggregate exercise price remained unchanged. The March 2025 Series A Warrants were extinguished as part of the Letter Agreement on June 17, 2025 as discussed below.

The initial exercise price of each March 2025 Series B Warrant issued in the March 2025 Private Placement was $1.98 per share of common stock. The March 2025 Series B Warrants were exercisable only following stockholder approval and expire two and one-half (2.5) years thereafter. The March 2025 Series B Warrants were subject to certain price reset and share combination event provisions which, if triggered, provided that the number of shares issuable upon exercise of the March 2025 Series B Warrants would downward adjust, subject to the Floor Price, and the number of shares issuable upon exercise therefor would increase such that the aggregate exercise price remained unchanged. In addition, the March 2025 Series B Warrant alternative cashless exercise provision provided that the March 2025 Series B Warrant could be exercised without further payment to the Company and for three times the number of shares of common stock then subject to the March 2025 Series B Warrant.

The March 2025 Pre-Funded Warrants will be exercisable from the date of issuance until exercised in full. The March 2025 Pre-Funded Warrants, March 2025 Series A Warrants and March 2025 Series B Warrants may not be exercised to the extent that immediately following such exercise, the holder would beneficially own greater than 4.99% (or, at the election of the holder, greater than 9.99%) of the Company’s outstanding common stock.

In connection with the March 2025 Private Placement, the Company issued 3,077,270 shares of common stock,19,650,000 shares of March 2025 Pre-Funded Warrants in lieu thereof, and accompanying 22,727,270 March 2025 Series A Warrants and 22,727,270 March 2025 Series B Warrants in consideration of new capital subscriptions. In addition, the Company issued 992,468 shares of common stock,4,322,400 March 2025 Pre-Funded Warrants in lieu thereof, and accompanying 5,314,870 March 2025 Series A Warrants and 5,314,870 March 2025 Series B Warrants, were issued in exchange for the cancelation of approximately $3.2 million in aggregate principal amount of the Exchange Notes.

The Company evaluated the terms of the February 2025 Warrants, March 2025 Series A Warrants and March 2025 Series B Warrants under authoritative guidance and concluded that each of the instruments should be accounted for as a liability instrument at fair value at issuance and each subsequent balance sheet date until settlement, with changes in the fair value recorded in the condensed consolidated statement of operations. The March 2025 Pre-Funded Warrants meet the criteria to be recorded as equity in the Company's condensed consolidated balance sheet.

The March 2025 Private Placement closed on March 7, 2025 (the “March 2025 Closing Date”). The aggregate gross proceeds at the March 2025 Closing Date totaled approximately $15.0 million. The gross proceeds, along with the fair value of the February 2025 Warrants of $0.5 million and Exchange Notes of $3.5 million as of the settlement date of March 4, 2025, were first allocated to the warrant liability instruments at their full fair value, totaling $13.2 million, with the remainder of $5.8 million recorded to common stock and additional paid-in capital in equity of the condensed consolidated balance sheet. Total offering expenses of $1.4 million were allocated based on the allocated amount of proceeds to warrant liabilities and equity, with $1.0 million recorded as warrant issuance expenses and expensed as incurred, and the remaining $0.4 million recorded as common stock issuance costs in additional paid-in capital.

On May 2, 2025, the Company’s stockholders approved, among other things, the March 2025 Series A Warrants and March 2025 Series B Warrants, and an amendment to the Company’s Certificate of Incorporation, as amended, to increase the authorized share capital of the Company to an amount sufficient to cover the shares of common stock issuable upon the exercise of the March 2025 Series A Warrants and March 2025 Series B Warrants. As part of the March 2025 Series A Warrants and March 2025 Series B Warrants agreement, the exercise price of the March 2025 Series A Warrants and March 2025 Series B Warrants were both reset on May 19, 2025 to $0.4373 per share. Prior to modification of the March 2025 Series B Warrants as part of the Letter Agreement (as further described below), certain March 2025 Series B Warrants were cashless exercised for the issuance of 21,482,492 shares of common stock The liability classified March 2025 Series B Warrants were remeasured immediately prior to exercise, which resulted in a $3.8 million gain on change in fair value for thenine months ended September 30, 2025, and a $0.8 million credit to additional paid-in capital.

Letter Agreement

On June 17, 2025, the Company and the March 2025 Private Placement Purchasers entered into a letter agreement (the “Letter Agreement”) with each of the March 2025 Private Placement Purchasers in an effort to, among other items, minimize the dilutive impact of the March 2025 Private Placement. The Letter Agreement extinguished the March 2025 Series A Warrants, modified the March 2025 Series B Warrants, and provided for the return and cancellation of Private Placement Shares and Pre-Funded Warrants, as further discussed in the following paragraphs.

As part of the Letter Agreement, all March 2025 Series A Warrants were cancelled. As of March 31, 2025, the fair value of the March 2025 Series A Warrant liability was $5.0 million. On June 17, 2025, the March 2025 Series A Warrants were immediately remeasured to fair value prior to their cancellation, which resulted in a $2.7 million gain on change in fair value attributable to the March 2025 Series A Warrants for the nine months ended September 30, 2025. The extinguishment of the March 2025 Series A Warrants was recognized as a $2.3 million capital contribution and recorded to additional paid-in capital, as the extinguishment was deemed equivalent to a capital contribution by existing shareholders of the Company.

As part of the same transaction, the March 2025 Series B Warrants were amended (the "Amended March 2025 Series B Warrants"), to (a) reduce the overall number of March 2025 Series B Warrant Shares issuable upon exercise of the Series B Warrants to an aggregate of up to 35,536,380 Series B Warrant Shares, (b) reduce the alternative cashless exercise ratio in such March 2025 Series B Warrants from 3:1 to 1:1, (c) remove provisions contained in the March 2025 Series B Warrants that would otherwise reduce the Company’s stockholders’ equity, and (d) reset the exercise price of the Amended March 2025 Series B Warrants back to $1.98 per share. As a result of the Letter Agreement, the Amended March 2025 Series B Warrants no longer fail the indexation guidance under ASC 815, Derivatives and Hedging, resulting in a reclassification from liability to equity. Immediately prior to reclassification, the March 2025 Series B Warrant liability was remeasured, and $4.5 million was recognized as a capital contribution and recorded to additional paid-in capital, as the modification of the March 2025 Series B Warrants was deemed equivalent to a capital contribution by existing shareholders of the Company. The remeasured fair value of the March 2025 Series B warrant liability, in the amount of $11.0 million was reclassified to equity. After the June 17, 2025 modification,34,794,540 of the Amended March 2025 Series B Warrants were cashless exercised resulting in the issuance of 34,794,540 shares of common stock.

Lastly, in conjunction with the Letter Agreement, each of the March 2025 Private Placement Purchasers agreed to return an aggregate of 12,241,986 Private Placement Shares and Pre-Funded Warrants issuable for an aggregate of 10,633,650 Pre-Funded Warrant Shares, held by them as of the date of the Letter Agreement, upon request of the Company (the "Letter Agreement Repurchase Option"), which were issued pursuant to the March 2025 Private Placement Purchase Agreement for a value of $0.66 per Private Placement Share and $0.659 per Pre-Funded Warrant. In exchange therefor, the Company agreed to repay the March 2025 Private Placement Purchasers holding such securities 115% of such value, using 90% of the proceeds from any capital raised by the Company subsequent to July 1, 2025. The Company and each of the March 2025 Private Placement Purchasers also agreed to waive any restrictions on subsequent equity sales and variable rate transactions contained in March 2025 Private Placement Purchase Agreement to allow for such repayment. During the three and nine months ended September 30, 2025, the Company paid the March 2025 Private Placement Purchasers $2.3 million and 3,472,740 shares were returned and cancelled under the terms of the Letter Agreement.

Support Letters

On July 11, 2025, the Company and certain March 2025 Private Placement Purchasers party to the Letter Agreement entered into that certain letter of support (the “Support Letters”) to modify certain portions of the Letter Agreement as between the Company and each of such March 2025 Private Placement Purchasers. In the event that the Company reasonably believes that, within the 30 days (the “Modification Period”) prior to the end of any fiscal quarter, the Company will have stockholders’ equity in an amount below $3.0 million as of the end of such fiscal quarter (the “Potential Equity Deficiency”), the Subsequent Financing Percentage (as defined in the Letter Agreement) shall be modified from 90% to 50% for any Subsequent Financing (as defined in the Letter Agreement) that occurs during the Modification Period pursuant to the Lincoln Park Purchase Agreement. Upon the end of the Modification Period, the Subsequent Financing Percentage shall be reverted to 90%, and such percentage shall apply to all Subsequent Financings, including all Subsequent Financings pursuant to the Lincoln Park Purchase Agreement. In the event the Company desires to trigger the modification of the Subsequent Financing Percentage, the Company agrees to supply the purchaser who executed a Support Letter with a pro forma balance sheet to evidence its reasonable belief of the Potential Equity Deficiency approximately 30 days prior to each end of fiscal quarter once the books for prior months are closed. In accordance withthe Support Letters, the Company made a cash payment of $0.5 million to such purchasers for a total cash payment of $2.3 million, which was recorded as a reduction to additional paid-in capital in the condensed consolidated balance sheet as of September 30, 2025. Such payment counted as cash received by the purchaser towards its Maximum Amount. Each Support Letter also granted the purchaser party to the letter a participation right in certain future financings of the Company for a period of 12 months.

First Amendment to the February 2025 SPEA

In connection with entering into the March 2025 SPA, the Company entered into that certain First Amendment to the February 2025 SPEA (the “First Amendment”). The February 2025 SPEA included certain limitations and restrictions on the Company’s ability to issue securities and provided the investors with participation rights in future equity and equity-linked offerings of securities, subject to certain limited exceptions (the “New Financing Restrictions”). Pursuant to the First Amendment, subject to consummation of the March 2025 Private Placement, the Company agreed to repurchase from the Investors $3.4 million in principal amount of the Company’s Funding Notes and accrued interest, along with the February 2025 Warrants issued pursuant to the February 2025 SPEA for an aggregate purchase price of $4.2 million. In exchange for the repurchase by the Company of the Funding Notes and SPEA Warrants, the February 2025 Purchasers agreed to consent to the March 2025 Private Placement and eliminate the New Financing Restrictions.

May 2024 Private Placement

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

The combined purchase price for each May 2024 Private Placement Share and May 2024 Pre-Funded Warrant from the Initial Subscription was $2.022, and $2.158 from the Additional Subscription, in each case together with one accompanying May 2024 Series A Warrant and one accompanying May 2024 Series B Warrant provided, that the Company Insiders participated in the Initial Subscription at an offering price of $2.04 per May 2024 Private Placement Share and accompanying May 2024 Series A Warrant and May 2024 Series B Warrant.

The exercise price of May 2024 Series A Warrants and May 2024 Series B Warrants from the Initial Subscription is $1.772 per share from the Initial Subscription and $1.908 per share from the Additional Subscription, provided that the exercise price for the May 2024 Series A Warrants and May 2024 Series B Warrants issued to the Company Insiders is $1.79 per share. Subject to certain ownership limitations, the May 2024 Series A Warrants will be exercisable until May 9, 2029, which is the five-year anniversary of issuance. Subject to certain ownership limitations, the May 2024 Series B Warrants will be exercisable until May 9, 2029. The May 2024 Pre-Funded Warrant will not expire until exercised in full.

Prior to the Amendment and Restatements (as defined below), if a holder of a May 2024 Series A Warrant or a May 2024 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 May 2024 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 May 2024 Series A Warrants and May 2024 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 1,439,988 shares of common stock,2,151,544 May 2024 Pre-Funded Warrants,3,591,532 May 2024 Series A Warrants and 3,591,532 May 2024 Series B Warrants to purchase shares of its common stock in connection with the May 2024 Private Placement. The net proceeds from the May 2024 Private Placement were approximately $7.3 million.

The Company reviewed the terms of the May 2024 Pre-Funded Warrants, May 2024 Series A Warrants and May 2024 Series B Warrants under the authoritative accounting guidance as of the issuance date.

As described above, the May 2024 Series A Warrants and May 2024 Series B Warrants were initially classified as liabilities for the reason that they could have been exercised into either shares of common stock or May 2024 Pre-Funded Warrants at the holder’s option and thus failed the indexation guidance under ASC 815, Derivatives and Hedging. The May 2024 Series A Warrant and May 2024 Series B Warrant liability were initially recorded at fair value as of the issuance date, and under the terms of the

May 2024 Series A Warrants and May 2024 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 May 2024 Series A Warrants and May 2024 Series B Warrants that eliminated the ability of the May 2024 Series A Warrants and May 2024 Series B Warrants to be exercised into Pre-Funded Warrants, and as a result, the reclassification of the May 2024 Series A and B Warrants from liability to equity section of the consolidated balance sheet.

The May 2024 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 May 2024 Series A Warrants and May 2024 Series B Warrants due to the initial liability classification. As disclosed in Note 4, Fair Value Measurements, the fair value of the May 2024 Series A Warrants and May 2024 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 consolidated statement of operations during year ended December 31, 2024, which represents the excess of the fair value of the May 2024 Series A Warrants and May 2024 Series B Warrants at issuance over the proceeds. During the year ended December 31, 2024, the Company recognized a fair value gain on warrant liability of $5.7 million. 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 consolidated statements of cash flows for the year ended December 31, 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 May 2024 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.

Amendment and Restatement of May 2024 Series A Warrants and May 2024 Series B Warrants

On August 9, 2024, the Company amended and restated the May 2024 Series A Warrants and May 2024 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 May 2024 Series A Warrants and May 2024 Series B Warrants to elect to purchase Pre-Funded Warrants upon exercise of the May 2024 Series A Warrants and May 2024 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 May 2024 Series A Warrants and May 2024 Series B Warrants.

In addition, the Amendment and Restatements eliminated the Company’s call right under the terms of the May 2024 Series A Warrants to call the May 2024 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 May 2024 Series A Warrants and May 2024 Series B Warrants.

As a result of the Amendment and Restatements, the May 2024 Series A Warrants and May 2024 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 June 17, 2025, the Company entered into a purchase agreement (the “Lincoln Park Purchase Agreement”) and a registration rights agreement (the “Registration Rights Agreement”) with Lincoln Park Capital Fund, LLC (“Lincoln Park”), pursuant to which the Company has the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park committed to purchase up to $50.0 million of shares of the Company’s common stock, $0.001 par value per share. Such sales of common stock by the Company are subject to certain limitations and conditions set forth in the Lincoln Park Purchase Agreement including, but not limited to, the filing and effectiveness of a registration statement (a "Lincoln Park Registration Statement"). As of September 30, 2025, under the Lincoln Park Registration Statements, the resale of up to a total of 50,000,000 shares are reserved for issuance and sale under the Lincoln Park Purchase Agreement.

Under the Lincoln Park Purchase Agreement, on any business day selected by the Company over the 36-month period commencing on June 23, 2025 (the "Purchase Date"), the Company may direct Lincoln Park to purchase up to 300,000 shares of common stock on such Purchase Date, so long as the closing stock price on The Nasdaq Capital Market is not below $0.10 on the applicable Purchase Date (a “Regular Purchase”); provided, however, that (i) a Regular Purchase may be increased to up to 400,000 shares, if the closing sale price per share of the common stock on The Nasdaq Capital Market is not below $0.50 on the applicable Purchase Date; and (ii) a Regular Purchase may be increased to up to 500,000 shares, if the closing sale price per share of the common stock on The Nasdaq Capital Market is not below $0.75 on the applicable Purchase Date. In any case, Lincoln Park’s maximum obligation under any single Regular Purchase will not exceed $1.0 million. The above-referenced share amount limitations and closing sale price thresholds are subject to adjustment for any reorganization, recapitalization, non-cash dividend, stock split, reverse stock split or other similar transaction as provided in the Purchase Agreement. The purchase price per share for each such Regular Purchase will be 97% of the lesser of: (i) the lowest sale price for the common stock on The Nasdaq Capital Market on the date of sale, and (ii) the average of the three lowest closing sale prices for the common stock on The Nasdaq Capital Market during the 10 consecutive business days ending on the business day immediately preceding the purchase date.

The Company also has the right to direct Lincoln Park, on any business day on which the Company has properly submitted a Regular Purchase notice for the maximum amount the Company is then permitted to sell to Lincoln Park in such Regular Purchase, to purchase an additional amount of the common stock (an “Accelerated Purchase”) of additional shares based on criteria established in the Lincoln Park Purchase Agreement. The purchase price per share for each such Accelerated Purchase will be 96.5% of the lesser of: (i) the volume weighted average price ("VWAP") during a specific time window on the Accelerated Purchase date as defined in the Lincoln Park Purchase Agreement, and (ii) the closing sale price of the Company’s common stock on The Nasdaq Capital Market on the same Accelerated Purchase date.

In addition to the Regular Purchase and Accelerated Purchase, the Company can sell to Lincoln Park an additional amount of common stock (an "Additional Accelerated Purchases"), which can be initiated multiple times on the same Additional Accelerated Purchase date. The purchase price per share for each such Additional Accelerated Purchase will be 96.5% of the lesser of: (i) the VWAP during a specific time windows on the Additional Accelerated Purchase date as defined in the Lincoln Park Purchase Agreement, and (ii) the closing sale price of the Company’s common stock on The Nasdaq Capital Market on the same Additional Accelerated Purchase date.

The sales of shares of common stock to Lincoln Park through a Regular Purchase, an Accelerated Purchase and an Additional Accelerated Purchases, depend upon 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 Lincoln Park Purchase Agreement to the Company depend on the frequency and prices at which the Company sells shares of its stock to Lincoln Park.

In accordance with the Lincoln Park Purchase Agreement, the Company was required to pay Lincoln Park an initial commitment fee of $0.5 million, which was paid through the issuance of 1,612,903 shares of common stock on August 14, 2025. The initial commitment fee was recorded as a reduction to additional paid-in capital in the condensed consolidated balance sheet as of September 30, 2025. The Company has agreed to pay an additional commitment fee of $0.5 million, 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 Lincoln Park Purchase Agreement.

As of the nine months ended September 30, 2025, the Company issued 44,575,496 shares under the Lincoln Park Purchase Agreement for gross proceeds of approximately $19.6 million. The Company incurred approximately $50,000 for legal fees in connection with the Lincoln Park Purchase Agreement.

Outstanding Warrants

As of September 30, 2025, the Company had the following warrants outstanding:

One share of common stock is issuable for each warrant upon exercise.

14. Stock-Based Compensation

Under the Company’s 2015 New Employee Incentive Plan (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. As of September 30, 2025, there were 76,025 shares of common stock remaining and available for future issuances under the 2015 Plan.

The Company’s 2020 Stock Incentive Plan (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. During the three months ended September 30, 2025, there was an additional 20,000,000 shares approved to be issued under the 2020 Plan. The 2020 Plan, as amended, provides for the issuance of up to 21,303,334 shares of common stock, plus the number of shares 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, 2025, there were 10,005,151 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 stock option activity for thenine months ended September 30, 2025 is as follows:

As of September 30, 2025, the total compensation cost related to non-vested stock options not yet recognized for all the Company’s plans is approximately $5.4 million, which is expected to be recognized as a result of vesting under service conditions over a weighted average period of 3.29 years.

Generally, restricted stock units represent the right to receive a certain number of shares of common stock subject to certain vesting conditions and other restrictions. The fair value of restricted stock units is determined by the closing market price on the grant date.

A summary of restricted stock unit activity for thenine months ended September 30, 2025 is as follows:

Restricted stock units granted during the nine months ended September 30, 2025 generally vest over a 36-month period upon satisfaction of service conditions. As of September 30, 2025, the total compensation cost related to non-vested restricted stock units not yet recognized for all the Company’s plans is approximately $1.5 million, which is expected to be recognized as a result of vesting under service conditions over a weighted average period of 2.75 years.

15. Segment Information

The Company operates underone reportable business segment to advance the development, manufacturing and commercialization of complex and innovative treatments for patients battling cancer and other life-threatening diseases. The determination of a single reportable business segment is consistent with the consolidated financial information regularly provided to the Company’s CODM. All of the Company's long-term assets and operations are located in the United States, and the measure of segment assets is reported on the condensed consolidated balance sheets as total assets. The Company’s CODM is its Chief Executive Officer, who reviews financial information presented on a consolidated basis for purposes of making operating decisions, allocating resources, andevaluating financial performance, including comparing actual results to budgets and forecasts to assess variances, identify trends, and guide strategic planning.

In addition to the significant expense categories included within the consolidated statements of operations, the below disaggregated amounts comprise significant research and development and general and administrative expenses. These expenses consist of (1) clinical, manufacturing and research contracts for research and development programs, (2) personnel-related expenses, including salaries, benefits and stock-based compensation, (3) professional fees, including third-party costs for goods and services such as lab supplies and contract research, and legal and other professional expenses, and (4) facility and other overhead expenses, including depreciation, occupancy, travel, insurance and other costs. Depreciation and amortization expense is consistent with those presented in the condensed consolidated statements of cash flows.

16. Subsequent Events

Financing Related Transactions

As of September 30, 2025, the Company recorded a $6.4 million liability in accounts payable and accrued expenses due to the March 2025 Private Placement Purchasers. Such liability declined by $1.3 million from September 30, 2025 to October 27, 2025 due to 1) a $0.9 million reduction as a result of the reselling of securities acquired in the March 2025 Private Placement by certain March 2025 Private Placement Purchasers, which was recorded as a reduction of the liability that would have been settled in cash, with a corresponding increase to stockholders’ equity, and 2) a payment of $0.4 million to the March 2025 Private Placement Purchasers subsequent to September 30, 2025, with 0.6 million shares of the Company’s common stock returned and cancelled under the terms of the Letter Agreement.

On October 28, 2025, the Company entered into an amendment to the Letter Agreement and the Support Letters with certain March 2025 Private Placement Purchasers (the “Amendment Agreement”), pursuant to which (a) the Support Letters were terminated other than with respect to the participation rights granted therein, and (b) the repayment mechanism under the Letter Agreement was modified. As modified, the Company is no longer required to use 90% of the proceeds from any subsequent financing to repay the March 2025 Private Placement Purchasers. Instead, the Company is only required to retain sufficient funds in an interest bearing account to cover such repayment obligations and make such repayments upon request by any March 2025 Private Placement Purchaser who executed the Amendment Agreement until each such purchaser has received cash either from the Company or from reselling securities acquired in the March 2025 Private Placement in an amount equal to 115% of the purchase price such purchaser paid in the March 2025 Private Placement. If such requests are made, the requesting purchaser must return shares acquired in the March 2025 Private Placement at a value of $0.66 per share.

In addition, the Company issued approximately 3.3 million shares on the Lincoln Park Purchase Credit Agreement, raising an additional $1.9 million of capital through October 29, 2025.

Houston Lease

On October 16, 2025, the Company entered into a lease (the “Houston Lease”) with LG 1 Property Owner LP, pursuant to which the Company agreed to lease approximately 11,370 rentable square feet of space located at 6420 Levit Green Boulevard, Houston, Texas 77021. The Houston Lease is expected to commence on or about November 1, 2026. The Houston Lease provides for a monthly base rent of $58,745, which increases annually by approximately 3%, plus the Company’s share of the building’s direct expenses. The Houston Lease has an initial term of 120 calendar months.