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OS Therapies Inc

For the period ended Dec 31, 2025. Filed Mar 31, 2026.

View on SEC.gov

About this filing

A company's yearly report to the SEC, with audited financial statements. It is the fullest account a company gives of its business, its finances and the risks it sees.

FY2025 · Filed Mar 31, 2026

OSTX$1.00+2.0%Stored close · as of Nov 6, 2026

What changed in Management’s Discussion and Analysis?

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Previous report: 10-K

Period ended 2024-12-31; filed 2025-03-31.

0001213900-25-026238

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Current report: 10-K

Period ended 2025-12-31; filed 2026-03-31.

0001213900-26-036629

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.

Compared 76 previous paragraphs and 88 current paragraphs.

38 unchanged; 18 reworded; 31 added; 20 removed; 0 previous and 1 current paragraphs rearranged.

Tables are not compared: 20 previous and 15 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.

A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.

Added paragraphs (31)

Current report

In 2021, we opened a clinical study to produce data for the FDA to evaluate the safety and efficacy of OST-HER2 in patients after resection of recurrent Osteosarcoma, which achieved full enrollment of 41 patients in October 2023. In the first quarter of 2025, we announced that our Phase IIb clinical trial achieved its primary endpoint with statistical significance. In October 2025, we announced final two-year overall survival data from the Phase IIb trial, in which 75% (27 of 36 evaluable patients) of OST-HER2-treated patients achieved two-year overall survival from the most recent pulmonary resection, compared with 40% in historical control patients (p < 0.0001). OST-HER2 was observed to be well-tolerated in the study. In January 2026, we announced positive immune biomarker data from the Phase IIb trial indicating that activation of immune blood biomarkers in the interferon gamma pathway correlated with, and was predictive of, overall survival, distinguishing long-term survivors (≥ two years) from short-term survivors (< one year). These biomarker findings are based on exploratory analyses and have not been validated as surrogate endpoints for clinical benefit. Based on the totality of the data generated to date, including the observed survival outcomes, safety profile and the significant unmet medical need in this patient population, we intend to engage with the FDA regarding potential regulatory pathways for OST-HER2.

Current report

We have engaged in ongoing regulatory interactions with the FDA, the United Kingdom MHRA, and the EMA regarding the clinical and biomarker data for OST-HER2 in recurrent, fully resected pulmonary metastatic Osteosarcoma. Following submission of the Non-Clinical and CMC modules of our BLA to the FDA at the end of January 2026, we anticipate submitting the clinical BLA module following an expected Type B meeting with the FDA in the second quarter of 2026 and completing conditional MAA submissions to both the MHRA and the EMA in the second quarter of 2026. We also anticipate releasing additional biomarker data in the second quarter of 2026 to further characterize immune pathway activation and its relationship to clinical outcomes. We expect to initiate confirmatory clinical studies in the third quarter of 2026 in support of conditional approval pathways. If OST-HER2 receives approval under the FDA’s Accelerated Approval Program prior to September 30, 2029, we would become eligible to receive a Priority Review Voucher under the Rare Pediatric Disease Designation Program.

Current report

In April 2025, after stockholder approval was obtained, this warrant liability was closed to stockholders’ equity. The following assumptions were made as of April 9, 2025 based on stockholder approval in the model for the aggregate warrants: (1) a fixed exercise price of $1.12 per share, which automatically reset and resulted in a reclassification of the warrant liability on April 9, 2025 to equity per ASC 815; (2) then-current common stock price of $1.34 per share on April 9, 2025; (3) discount rate of 4.06%; and (4) expected stock price volatility of 23.26%.

Current report

As of December 31, 2025 and 2024, we had federal NOLs of $33,561,091 and $22,236,580, respectively. Our 2019 NOL carryforward of $292,144 will expire in tax years through 2037. NOLs generated in tax years 2020 and later may carry forward indefinitely; however, the deductibility of such NOLs is subject to certain limitations under the Code. Accordingly, we have established a full valuation allowance to offset our deferred tax assets due to uncertainty regarding the realization of these benefits.

Current report

Our issuances of common stock have resulted in ownership changes as defined by Section 382 of the Code. We have not yet performed a formal Section 382 study, and it is possible that a future analysis in 2026 could conclude that a substantial portion, or potentially all, of our NOL and R&D tax credit carryforwards may be limited or rendered unusable under Sections 382 and 383 of the Code. As a result, a portion of these carryforwards could expire unused. We are subject to U.S. federal tax examinations for the year 2021, given that NOL carryforwards from 2019 and subsequent years may be applied to current or future tax returns.

Current report

For the years ended December 31, 2025 and 2024, our direct research and development expenses related to OST-HER2 primarily consisted of laboratory fees, vendor costs, and staff payroll. In 2025, these expenses included approximately $1.6 million for laboratory fees and clinical support related to Phase IIb clinical trial preparation, $12.7 million for advisor fees, and $0.2 million for legal costs associated with the completion of IND-enabling studies. Direct research and development expenses related to our OST-tADC platform were approximately $0.0 million for both the years ended December 31, 2025 and 2024.

Current report

***General and Administrative Expenses.***General and administrative expenses were approximately $12.3 million for the year ended December 31, 2025, compared to approximately $4.0 million for the year ended December 31, 2024. The increase was primarily due to higher marketing and investor relations costs of $2.4 million, as well as advisory fees of $3.3 million and legal fees of $1.6 million incurred in connection with the PIPE Financing and equity line of credit that was terminated.

Current report

For the years ended December 31, 2025 and 2024, net cash used in operating activities was approximately $14.2 million and $7.3 million, respectively. This primarily reflected net losses of approximately $28.8 million and $8.9 million, partially offset by non-cash charges of approximately $5.4 million and $1.7 million, respectively, and net cash provided by changes in operating assets and liabilities of approximately $9.1 million and $(0.1) million, respectively.

Current report

For the years ended December 31, 2025 and 2024, net cash used in investing activities was approximately $0.5 million and $0.0 million, respectively.

Current report

For the years ended December 31, 2025 and 2024, net cash provided by financing activities was approximately $9.4 million and $12.8 million, respectively. During 2025, cash inflows included approximately $1.1 million from our PIPE Financing and approximately $8.4 million from our warrant exercise inducement and related exchange and sale of common stock.

Current report

On December 24, 2024, we entered the PIPE Purchase Agreement with certain institutional and accredited investors, substantially all of whom were existing stockholders, pursuant to which we issued an aggregate of 1,775,750 shares of Series A Preferred Stock and Series A Warrants exercisable into 1,775,750 shares of common stock, generating gross proceeds of approximately $7.1 million before fees and expenses. In connection with the PIPE Financing, we paid Brookline cash fees totaling $159,685 and $79,723 to Brookline and Brookline’s selected dealer, respectively, plus Agent Warrants to purchase an aggregate of 59,848 shares of common stock.

Current report

On August 8, 2025, we entered into the Sales Agreement with the Sales Agents relating to shares of our common stock. Pursuant to the Sales Agreement, we may offer and sell shares of our common stock from time to time having an aggregate offering price of up to $18,000,000 through or to the Sales Agents. We will pay each of the Sales Agents a total commission for its services in acting as agent in the sale of common stock up to 3.0% of the gross sales price per share of all shares sold through it as agent under the Sales Agreement. The amount of proceeds we will receive will depend upon the actual number of shares of our common stock sold and the market price at which such shares are sold. Because there is no minimum offering amount required as a condition to close a sale, the actual total public offering amount, commissions and proceeds to us are not determinable at this time. Sales of our common stock under the Sales Agreement are being made pursuant to a prospectus supplement filed with the SEC on August 25, 2025. As of March 26, 2026, we have sold an aggregate of 282,679 shares of our common stock for aggregate gross proceeds of $530,162 pursuant to the Sales Agreement.

Current report

On July 11, 2025, we completed a final closing of the First Inducement Offering. On September 2, 2025, we closed on the Second Inducement Offering. On January 14, 2026, we closed on the Third Inducement Offering.

Current report

In connection with the First Inducement Offerings and Second Inducement Offering, and pursuant to certain inducement offer letter agreements, holders of Series A Warrants exercised for cash their Series A Warrants to purchase an aggregate of 7,154,338 shares of our common stock at the then current exercise price of $1.12 per share and in exchange we issued to such holders New Warrants to purchase up to an aggregate of 7,154,338 shares of our common stock at an exercise price of $3.00 per share, subject to adjustment as provided therein. The New Warrants are immediately exercisable from the date of issuance and have a term of exercise of five years from such date.

Current report

The Third Inducement Offering was made to less than 10 accredited investors that held New Warrants to purchase up to an aggregate of 5,382,148 shares of our common stock having a then current exercise price of $3.00 or $2.10 per share. Pursuant to certain inducement offer letter agreements, such holders of New Warrants exercised for cash their New Warrants to purchase 2,499,558 shares of our common stock at a reduced exercise price of $1.40 per share and in exchange we issued to such holders 2026 Warrants to purchase up to an aggregate of 2,499,558 shares of our common stock at an exercise price of $1.40 per share, subject to adjustment as provided therein. The 2026 Warrants are immediately exercisable from the date of issuance and have a term of exercise of five years from such date.

Current report

We engaged the Solicitation Agent to act as our exclusive warrant solicitation agent in connection with the Inducement Offerings and paid the Solicitation Agent a cash fee equal to 5.0%, 1.5% and 8.0% of the total gross cash proceeds received from the exercise by the holders of their respective warrants in connection with the First Inducement Offering, Second Inducement Offering and Third Inducement Offering, respectively. We also paid the Solicitation Agent $15,000 and $25,000 for its reasonable legal and other expenses in connection with the First Inducement Offering and Third Inducement Offering, respectively.

Current report

The gross proceeds to us from the Inducement Offerings, before deducting transaction fees and other offering expenses, were approximately $11.5 million. We are using the net proceeds from the Inducement Offerings to support U.S. and international regulatory and pre-commercial efforts aimed at securing marketing authorizations for OST-HER2 in the prevention or delay of recurrent, fully resected, pulmonary metastatic Osteosarcoma, provide funding for our wholly owned subsidiary OS Animal Health’s proposed spin-off transaction preparations, and for general corporate purposes.

Current report

Privately Negotiated Warrant Exercise Inducement and Exchange Agreements

Current report

From January 10, 2026 through February 2026, we entered into privately negotiated inducement offer letters, pursuant to which certain remaining holders of our New Warrants exercised for cash their New Warrants to purchase an aggregate of 123,216 shares of our common stock at a reduced exercise price of $1.40 per share and in exchange we issued new warrants to purchase up to an aggregate of 123,216 shares of our common stock at an exercise price of $1.40 per share, subject to adjustment as provided therein. Such new warrants are immediately exercisable from the date of issuance and have a term of exercise of five years from such date. We received gross proceeds of approximately $172,502 from the exercise of these New Warrants.

Current report

On March 4, 2026, pursuant to the Bridge SPA, we issued to certain accredited investors in the Bridge Financing (i) Bridge Notes in an aggregate principal amount of $2,200,000 and (ii) Bridge Warrants to purchase up to an aggregate of 1,666,667 shares of our common stock, for aggregate gross proceeds of $2,000,000, before deducting placement agent fees and other Bridge Financing expenses. The Bridge Notes mature on March 4, 2027 and accrue interest at a rate of 4.0% per annum. The Bridge Warrants were immediately exercisable upon issuance, expire five years from the date of issuance and have an exercise price of $1.40 per share, subject to adjustment as provided therein.

Current report

The Bridge Notes were sold at a 10% original issue discount, such that for each $100,000 invested by a purchaser, such purchaser received a Bridge Note in the principal amount of $110,000. The Bridge Notes are convertible into shares of our common stock under certain circumstances. If we complete a “Qualified Offering,” defined as a registered public offering or registered direct offering resulting in at least $2.5 million in gross proceeds from new money investments, the outstanding principal, together with all accrued and unpaid interest, will automatically convert into the securities sold in such offering at the offering price. Additionally, prior to any such Qualified Offering or repayment of the Bridge Notes, holders may elect to convert the Bridge Notes, in whole or in part, into shares of our common stock at a conversion price equal to 90% of the average daily volume-weighted average price of our common stock during the 10 trading days immediately preceding the holder’s conversion notice, subject to adjustment.

Current report

We intend to use the net proceeds of the Bridge Financing to fund clinical development activities, including ongoing and planned clinical trials, and advance our research and development programs, as well as for working capital and general corporate purposes.

Current report

We engaged a SEC-registered broker dealer and FINRA member to act as the exclusive placement agent for the Bridge Financing. In connection with the Bridge Financing, we paid to the placement agent (a) a cash fee equal to 7.0% of the aggregate gross cash proceeds received by us in connection with the Bridge Financing and (b) a one-time expense reimbursement of $25,000 for its legal and other expenses incurred in connection with the Bridge Financing.

Current report

Biolacuna Ltd. We have contracted with Biolacuna Ltd, a global life sciences advisory firm, to assist with the following agencies requirements to register OST-HER2 and gain approval of its use in the respective regions:

Current report

For the year ended December 31, 2025, we paid $11,629,063 in consulting fees, which includes refundable value-added tax (“VAT”) expenses. As of December 31, 2025, accounts payable related to consulting fees and VAT totaled $6,468,216.

Current report

University of Pennsylvania. On April 9, 2025, we acquired from Ayala the HER2 Assets. Pursuant to the terms of the HER2 Purchase Agreement, the amended and restated development, license and supply agreement with Advaxis terminated. In connection with the acquisition of the HER2 Assets, we were assigned by Ayala a license agreement with the Trustees of the University of Pennsylvania covering the use of HER2 construct patents. Under the terms of the license agreement, we are required to pay an annual license fee to the Trustees of the University of Pennsylvania. In April 2025, we paid a fee of $266,317 for the year ended December 31, 2025. In addition, we are obligated to pay a royalty equal to 1.5% of net sales related to:
Removed paragraphs (20)

Previous report

No new treatments have been approved by the FDA for human Osteosarcoma for more than 40 years. In humans, Osteosarcoma is an extremely rare cancer that primarily affects children, teenagers and young adults generally under 40 years of age. We are not aware of any competing adjuvant therapy for Osteosarcoma to be tested in children that is further along in the development process than OST-HER2. This disease is difficult to diagnose. The standard of care following first line therapies is simply to screen and wait for possible recurrence/metastasis, or the development of secondary malignant growths at a distance from a primary site of cancer. Studies published in the Journal of Clinical Oncology, “Osteosarcoma Relapse After Combined Modality Therapy: An Analysis of Unselected Patients in the Cooperative Osteosarcoma Study Group (COSS),” by Kempf-Bielack B., et al. (January 2005), and “Second and Subsequent Recurrences of Osteosarcoma: Presentation, Treatment, and Outcomes of 249 Consecutive Cooperative Osteosarcoma Study Group Patients,” by Bielack S., et al. (February 2009), reported that recurrence/metastasis happens in approximately half of all patients within 12 to 18 months following initial remittance. For those patients that experience recurrence, metastasis is typically to the lungs and brain, with survival rates of approximately 13% over the next year, according to these studies.

Previous report

As of December 31, 2024, we had U.S. federal net operating loss carry forwards of approximately $22,236,580, which may be available to offset future taxable income. The federal net operating loss carry forward indefinitely but may only be used to offset 80% of annual taxable income. As of December 31, 2024, we also had federal and state general business tax credit carry forwards of $1,672,876 available to offset future tax liabilities and expire at various dates beginning in January 1, 2040. We have R&D credits that we opted to convert and use toward payroll taxes in amounts equal to $268,568 as of December 31, 2024. As of December 31, 2024, we also had federal and state research and development tax credit carry forwards of approximately $1,672,876, which may be available to offset future tax liabilities and expire at various dates beginning January 1, 2043 and January 1, 2042, respectively.

Previous report

In 2024, the direct research and development expenses related to OST-HER2 were $2.2 million. In 2023, such expenses were primarily lab fees, vendor expenses and payroll. Additionally, in 2024 and 2023, we incurred expenses for our Phase IIb clinical trial. OST-tADC related direct research and development expenses were approximately $0.05 million and $0.2 million for the years ended December 31, 2024 and 2023, respectively.

Previous report

***General and Administrative Expenses.***General and administrative expenses for the year ended December 31, 2024 were approximately $4.0 million compared to $1.1 million for the year ended December 31, 2023. This increase was primarily attributed to increased payments to consultants, along with staff related payroll and legal fees.

Previous report

The Series A preferred stock coupon dividend requirement of $31,250 for the year ended December 31, 2024 represents an expense that terminated during the period ended March 31, 2024 upon the conversion of our old Series A preferred shares into shares of our common stock. The Series A preferred stock coupon dividend requirement of $125,000 for the year ended December 31, 2023 represents a 12-month expense. We issued Series A convertible preferred stock with a deemed dividend of $1.97 million as of December 31, 2024.

Previous report

During the years ended December 31, 2024 and 2023, operating activities used approximately $7.3 million and $3.0 million of cash, respectively, resulting from our net loss of approximately $8.9 million and $7.8 million, respectively, offset by net non-cash charges of approximately $1.7 million and $2.8 million, respectively, partially offset by net cash provided by changes in our operating assets and liabilities of approximately $0 million and $2.0 million, respectively.

Previous report

During the years ended December 31, 2024 and 2023, net cash provided by investing activities was approximately $0 and $1,145, respectively.

Previous report

For the years ended December 31, 2024 and 2023, net cash provided by financing activities was approximately $12.8 million and $2.9 million, respectively.

Previous report

On December 24, 2024, we entered into the Purchase Agreement with the selling stockholders, substantially all of whom were existing stockholders of the Company, pursuant to which we agreed to issue and sell to the selling stockholders the Units for aggregate gross proceeds of not less than $6 million and not more than $10 million. At two closings occurring on December 31, 2024 and January 14, 2025, we issued to the selling stockholders an aggregate of (i) 1,775,750 shares of Series A Preferred Stock and (ii) Series A Warrants initially exercisable into 1,775,750 shares of common stock. The gross proceeds from the closing of the Private Placement, before deducting transaction fees and other estimated Private Placement expenses, were approximately $7,103,000. The Purchase Agreement requires us to seek stockholder approval for any transactions contemplated by the Purchase Agreement and the related documents for which the rules of the NYSE American require stockholder approval (“Stockholder Approval”) and to hold a special meeting of stockholders for the purpose of obtaining Stockholder Approval not later than April 10, 2025. In the event Stockholder Approval is not obtained at the first meeting, we are required to call a meeting every four months seeking Stockholder Approval until Stockholder Approval is obtained.

Previous report

Brookline acted as exclusive placement agent for the issuance and sale of the securities in the Private Placement. Pursuant to the terms of the Placement Agency Agreement, we agreed to pay Brookline an aggregate cash fee (the “Cash Fee”) equal to (i) 7% of the gross proceeds received by the Company from the sale of the securities in the Private Placement to selling stockholders other than certain selling stockholders identified on a schedule thereto (“Reduced Fee Purchasers”) plus (ii) 3% of the gross proceeds received by the Company from the sale of the securities in the Private Placement to Reduced Fee Purchasers, plus expenses; provided that Ceros is entitled to 33.3% of the Cash Fee.

Previous report

In addition, we agreed to pay Brookline or its designees a fee in the form of the Agent Warrants. The Agent Warrants are initially exercisable into a number of shares of common stock equal to (i) 7% of the number of shares of common stock initially issuable pursuant to the shares of Series A Preferred Stock issued to selling stockholders other than Reduced Fee Purchasers in the Private Placement plus (ii) 3% of the number of shares of common stock initially issuable pursuant to the shares of Series A Preferred Stock issued Reduced Fee Purchasers in the Private Placement; provided that Ceros is entitled to 33.3% of the Agent Warrants. The terms of the Agent Warrants are substantially similar to the terms of the Series A Warrants, except the Agent Warrants are not exercisable until Stockholder Approval is obtained. At two closings occurring on December 31, 2024 and January 14, 2025, (i) Brookline received an aggregate cash fee of $159,685 and 39,918 Agent Warrants, and (ii) Ceros received an aggregate cash fee of $79,723 and 19,930 Agent Warrants.

Previous report

***Advaxis.*In November 2020, we entered into an amended and restated development, license and supply agreement with Advaxis, Inc. (now Ayala Pharmaceuticals, Inc.) (“Advaxis”), a clinical-stage biotechnology company focused on the development and commercialization of proprietaryLm (Listeria monocytogenes)-LLO (Listeriolysin O) cancer immunotherapies. Pursuant to this agreement, Advaxis granted a license to us that allows us to utilize Advaxis’ ADXS-HER2 construct patents to develop and commercialize ADXS-HER2, our lead product candidate (OST-HER2). The agreement was subsequently amended in April 2021 to modify the payment amounts for Milestones 2 and 3 listed in the table below. Under the terms of the amended agreement, we are required to pay to Advaxis (i) a one-time, non-refundable payment of $1,550,000 (the “License Commencement Payment”) and (ii) certain amounts based on the achievement of the milestones described in the payment schedule below. As of December 31, 2024, we paid to Advaxis a total of $2,925,000, consisting of (i) the License Commencement Payment for Milestone 1 and (ii) $1,375,000 for Milestone 2.

Previous report

Payments towards the License Commencement Payment have been recorded as licensing expenses in our Statement of Operations and Comprehensive Loss for the year ended December 31, 2022. We expect to achieve Milestone 3 in 2025. The payment schedule for milestones and corresponding payment amounts is set forth below.

Previous report

All milestone payments are non-creditable and non-refundable and are due and payable upon the achievement of the milestone, regardless of any failure by us to provide notice to Advaxis of such achievement.

Previous report

In addition to the payments upon achievement of the milestones listed in the above payment schedule, we are required to pay to Advaxis (i) a percentage in the high single digits to low double digits of (a) upfront sublicense fees or (b) clinical or regulatory milestone payment amounts, paid by a sublicensee to us in consideration of a sublicense grant to such sublicensee, and (ii) a quarterly royalty of a percentage in the high single digits to low double digits of net sales of our products containing the ADXS-HER2 constructs.

Previous report

On January 28, 2025, we entered into the HER2 Purchase Agreement with Ayala, pursuant to which we agreed, subject to the terms and conditions set forth therein, to acquire from Ayala the HER2 Assets. Pursuant to the terms of the HER2 Purchase Agreement, the change in milestone payments and royalty consideration owed as it relates to the OST-HER2 program will be follows:

Previous report

***George Clinical.***In June 2020, we entered into a services agreement, as amended, with George Clinical, Inc., a clinical contract research organization. Pursuant to this agreement, we engaged George Clinical to use its clinical research services for our study entitled “An Open Label, Phase 2 Study of Maintenance Therapy with OST-HER2 after Resection of Recurrent Osteosarcoma.” Under the terms of the agreement, we are required to pay to George Clinical certain fees described in the fee schedule below. The total new budget under the agreement is approximately $2,423,928. For the years ended December 31, 2024 and 2023, we paid $714,943 and $444,421, respectively, to George Clinical. These payments have been recorded as research and development expenses in our Statement of Operations and Comprehensive Loss. The fee schedule for certain fees and corresponding payment amounts is set forth below.

Previous report

George Clinical tracks and invoices us for the number of task units completed and pass-through costs are invoiced each month in arrears based on actual costs without mark-up. The PTC Fee Advance will be used to offset the first few months of invoices payable. As of December 31, 2024, the balance due to George Clinical was $359,617.
Reworded paragraphs (18)

Previous wording

You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and related notes appearing elsewhere in this annual report. Some of the information contained in this discussion and analysis or set forth elsewhere in this annual report, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this annual report, our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis.

Current wording

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and related notes appearing elsewhere in this annual report. Some of the information contained in this discussion and analysis or set forth elsewhere in this annual report, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this annual report, our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis.

Previous wording

We are a clinical stage biopharmaceutical company focused on the identification, development and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. Our mission is to address the significant need for new treatments in cancers of the bone in children and young adults. Osteosarcoma is an extremely challenging and often aggressive cancer that has particular treatment challenges due to its location, changing genotypes and high metastases rates. We are currently seeking to answer the call for new treatments that will prevent metastasis and the recurrence of metastases with our lead core product candidate OST-HER2 (also known as OST31-164), a cancer immunotherapy product candidate that produces a cellular immune response against the cancer antigen HER2. In 2021, we opened a clinical study to produce data for the U.S. Food and Drug Administration (FDA) to evaluate the safety and efficacy of OST-HER2 in patients after resection of recurrent Osteosarcoma, which achieved full enrollment of 41 patients in October 2023. We expect topline results from all 41 patients enrolled by the fourth quarter of 2024 and, if successful, intend to seek regulatory approval for OST-HER2 for the prevention of metastases in Osteosarcoma in 2025. Upon success in gaining regulatory approval from the FDA with OST-HER2 in Osteosarcoma, we intend to evaluate OST-HER2’s potential use, both alone and in combination with HER2 targeting antibodies such as Herceptin®, in other solid tumors including breast, esophageal and lung cancers. OST-HER2 has potential uses in both the prevention of metastases in solid tumors, and therapeutically against HER2-expressing solid tumors treated with HER targeting antibodies.

Current wording

We are a clinical stage biopharmaceutical company focused on the identification, development and commercialization of treatments for Osteosarcoma (OS) and other solid tumors. Our mission is to address the significant need for new treatments in cancers of the bone in children and young adults. Osteosarcoma is an extremely challenging and often aggressive cancer that has particular treatment challenges due to its location, changing genotypes and high metastases rates. We are currently seeking to answer the call for new treatments that will prevent metastasis and the recurrence of metastases with our lead core product candidate OST-HER2 (also known as OST31-164), a cancer immunotherapy product candidate that produces a cellular immune response against the cancer antigen HER2.

Previous wording

We also own rights to OST-Tunable Drug Conjugate (OST-tADC) platform, a next generation antibody-drug conjugate (ADC) silicone dioxide linker technology. “Tunable” is a term used in drug development that refers to the properties that can be influenced by chemical modifications, and “antibody-drug conjugate” or ADC is a term used to describe a drug made up of a monoclonal antibody attached to a cytotoxic payload, or a highly active and toxic pharmaceutical molecule, through chemical linkers. The ADC links an antibody that can home in on a targeted tumor to deploy the cytotoxic payload or toxic agent against the tumor. Furthering our founding mission, we intend to investigate clinical indications for OST-tADC in Osteosarcoma and other solid tumors.

Current wording

We also own rights to an OST-tADC platform, a next generation ADC silicone dioxide linker technology. “Tunable” is a term used in drug development that refers to the properties that can be influenced by chemical modifications, and “antibody-drug conjugate” or ADC is a term used to describe a drug made up of a monoclonal antibody attached to a cytotoxic payload, or a highly active and toxic pharmaceutical molecule, through chemical linkers. The ADC links an antibody that can home in on a targeted tumor to deploy the cytotoxic payload or toxic agent against the tumor. Furthering our founding mission, we intend to investigate clinical indications for OST-tADC in Osteosarcoma and other solid tumors.

Previous wording

Our financial statements are prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The preparation of our financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

Current wording

Our consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The preparation of our consolidated financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our consolidated financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

Previous wording

Critical accounting policies are those that, in management’s view, are most important to the portrayal of a company’s financial condition and results of operations and most demanding on their calls on judgment, often as a result of the need to make estimates about the effect of matters that are inherently uncertain and may change in subsequent periods. While our significant accounting policies are described in more detail in Note 2 to our financial statements appearing elsewhere in this annual report, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our financial statements.

Current wording

Critical accounting policies are those that, in management’s view, are most important to the portrayal of a company’s financial condition and results of operations and most demanding on their calls on judgment, often as a result of the need to make estimates about the effect of matters that are inherently uncertain and may change in subsequent periods. While our significant accounting policies are described in more detail in Note 2 to our consolidated financial statements appearing elsewhere in this annual report, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our consolidated financial statements.

Previous wording

The Series A Warrants issued in connection with the Purchase Agreement are recognized as a derivative liability in accordance with ASC 815. We recognize the warrant instruments as a liability at fair value and adjust the instruments to fair value at each reporting period. The liability is subject to re-measurement at each balance sheet date until exercised or reclassified, and any change in fair value is recognized in our consolidated statements of operations. The fair value of the Series A Warrants was measured using a Binomial simulation model. The determination of the fair value of the warrant liability may be subject to change as more current information becomes available, and, accordingly, the actual results could differ significantly. As the fair value of the warrant liability is based on a Binomial simulation model, we determined the fair value of the warrant liability was a critical accounting estimate.

Current wording

The Series A Warrants issued in connection with the PIPE Financing in December 2024 and January 2025 are recognized as a derivative liability in accordance with ASC 815. We recognize the warrant instruments as a liability at fair value and adjust the instruments to fair value at each reporting period. The liability is subject to re-measurement at each balance sheet date until exercised or reclassified, and any change in fair value is recognized in our consolidated statements of operations. The fair value of the Series A Warrants was measured using a Binomial simulation model. The determination of the fair value of the warrant liability may be subject to change as more current information becomes available, and accordingly, the actual results could differ significantly. The derivative warrant liability is classified as non-current liabilities as their liquidation is not reasonably expected to require the use of current assets or require the creation of current liabilities in 2024.

Previous wording

***General and Administrative Expenses.***General and administrative expenses consist primarily of salaries and related costs, including stock-based compensation, for personnel in executive, finance and administrative functions. General and administrative expenses also include professional fees for legal, patent, consulting, investor and public relations and accounting and audit services.

Current wording

***General and Administrative Expenses.***General and administrative expenses consist primarily of salaries and related costs, including stock-based compensation, for personnel in executive, finance and administrative functions. General and administrative expenses also include professional fees for legal, consulting, investor and public relations and accounting and audit services.

Previous wording

***Cumulative Series A Preferred Stock Dividend.***The Series A preferred stock dividend requirement represents the coupon dividends on our preferred stock that has since been converted and is identified as a separate component of our statement of operations to compute net income (loss) available to common stockholders. The coupon dividends are computed at 5% of the principal per annum and are recorded monthly. The cumulative accrued dividend at December 31, 2024 and 2023 was $375,000 and $343,750, respectively. The Series A preferred stock was converted into common stock on a 1:1 basis in February 2024, and the last coupon dividend was issued in the quarter ended March 31, 2024.

Current wording

***Cumulative Series A Preferred Stock Dividend.***The Series A preferred stock dividend requirement represents the coupon dividends on our preferred stock that has since been converted and is identified as a separate component of our statement of operations to compute net income (loss) available to common stockholders. The coupon dividends are computed at 5% of the principal per annum and are recorded monthly. The cumulative accrued dividend as of December 31, 2025 and 2024 was $375,000 and $375,000, respectively. The Series A preferred stock was converted into common stock on a 1:1 basis in February 2024, and the last coupon dividend was issued in the quarter ended March 31, 2024.

Previous wording

***Income Taxes.***Since our inception, we have not recorded income tax benefits for the net operating losses incurred or the research and development tax credits generated in each year, due to the uncertainty of realizing a benefit from those items.

Current wording

***Income Taxes.***Since our inception, we have not recognized income tax benefits for the net operating losses (“NOLs”) incurred or the research and development (“R&D”) tax credits generated each year due to uncertainty regarding the realization of these benefits.

Previous wording

***Deferred Offering Costs.***Deferred offering costs consisted of legal, accounting, printing and filing fees that we capitalized, which will be offset against the gross proceeds from our initial public offering.

Current wording

***Deferred Offering Costs.***Deferred offering costs consisted of legal, accounting, printing and filing fees that we capitalized, which were offset against the gross proceeds from our initial public offering.

Previous wording

***Research and Development Expenses.***Research and development expenses were approximately $2.8 million for the year ended December 31, 2024 compared to approximately $3.2 million for the year ended December 31, 2023. This decrease was primarily due to a decrease in vendor expenses associated with our OST-tADC product. The following table summarizes our research and development expenses for the years ended December 31, 2024 and 2023:

Current wording

***Research and Development Expenses.***Research and development expenses were approximately $16.4 million for the year ended December 31, 2025, compared to approximately $2.8 million for the year ended December 31, 2024. The increase was primarily driven by higher vendor costs related to our ongoing efforts to pursue FDA approval for our Phase IIb clinical trial and the preparation of data for submission to various global regulatory authorities. This increase was partially offset by a reduction in vendor expenses associated with our OST-tADC platform technology.

Previous wording

***Interest Expense.***Interest expense for the year ended December 31, 2024 was approximately $2.1 million compared to $3.5 million for the year ended December 31, 2023.

Current wording

***Interest Expense.***Interest expense was approximately $0.0 million for the year ended December 31, 2025, compared to approximately $2.0 million for the year ended December 31, 2024.

Previous wording

Since our inception, we have incurred significant operating losses. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of our product candidates. For the years ended December 31, 2024 and 2023, we reported a net loss of approximately $8.9 million and $7.8 million, respectively, and had an accumulated deficit of approximately $41 million and $29.5 million, respectively. We expect to incur significant expenses at an increasing rate and increasing operating losses for the foreseeable future.

Current wording

Since our inception, we have incurred significant operating losses. Our ability to generate sufficient product revenue to achieve profitability will depend on the successful development and eventual commercialization of our product candidates. For the years ended December 31, 2025 and 2024, we reported net losses of approximately $28.7 million and $8.6 million, respectively, and had accumulated deficits of approximately $67.2 million and $38.0 million, respectively. We expect to continue incurring significant expenses and increasing operating losses for the foreseeable future.

Previous wording

As of December 31, 2024 and 2023, we had cash of approximately $5.5 million and $0.04 million, respectively. We have funded our operations to date primarily from the sale of our convertible notes and Series A securities in our private placements, as well as the sale of our common stock in our initial public offering, which have provided total gross proceeds of $34.6 million as of March 28, 2025. We believe that the net proceeds from our private placements and initial public offering, together with our existing cash, will enable us to fund our operating expenses and capital expenditure requirements for the next nine to 12 months.

Current wording

As of December 31, 2025 and 2024, we had cash of approximately $0.3 million and $5.5 million, respectively. To date, we have primarily funded our operations through the sale of our securities in public offerings and private placements and warrant exercise inducement and exchange transactions, generating total gross proceeds of approximately $41.1 million as of March 26, 2026. We believe that the net proceeds from these transactions, together with our existing cash, will be sufficient to fund our operating expenses and capital expenditures for at least the next twelve months.

Previous wording

Net cash provided by changes in our operating assets and liabilities for the years ended December 31, 2024 and 2023 consisted primarily of an increase (decrease) in accounts payable of approximately $ (1.1) million and $1.3 million, respectively, an increase (decrease) in accrued interest of approximately $0.6 million and $0.8 million, respectively, and a change in accrued payroll of approximately $0 million and $(0.3) million, respectively.

Current wording

The changes in operating assets and liabilities for the years ended December 31, 2025 and 2024 primarily consisted of: an increase (decrease) in accounts payable of approximately $8.3 million and $(1.1) million, respectively; an increase in accrued interest of approximately $0.0 million and $0.6 million, respectively; and changes in accrued expenses of approximately $0.9 million and $0.4 million, respectively.

Previous wording

Non-cash charges for the years ended December 31, 2024 and 2023 were primarily the result of the amortization of debt discount on our convertible debt of approximately $1.4 million and $2.6 million, respectively. Changes in accounts payable, accrued expenses and other current liabilities and prepaid expenses and other current assets in all periods were generally due to growth in our business, the advancement of our research programs and the timing of vendor invoicing and payments.

Current wording

For the years ended December 31, 2025 and 2024, non-cash charges were primarily due to changes in the fair value of our warrant liability of $(1.4) million and $0.0 million, respectively, as well as common stock issued for services and stock-based compensation of approximately $4.87 million and $0.3 million, respectively, and amortization of non-cash prepaids of $1.0 million and $0.0 million, respectively. Changes in accounts payable, accrued expenses and other current liabilities, and prepaid expenses and other current assets in each period primarily reflected the growth of our business, the advancement of our research programs, and the timing of vendor invoicing and payments.

Previous wording

In connection with the license agreement, we also agreed to issue the BlinkBio Convertible Note. See “—Convertible Notes” above for more information on the BlinkBio Convertible Note.

Current wording

In connection with the license agreement, we also agreed to issue the BlinkBio Convertible Note. See “Financing Activities—BlinkBio” above for more information on the BlinkBio Convertible Note.

Previous wording

A description of recently issued accounting pronouncements that may potentially impact our financial position and results of operations is disclosed in Note 2 to Notes to the Financial Statements appearing elsewhere in this annual report.

Current wording

A description of recently issued accounting pronouncements that may potentially impact our financial position and results of operations is disclosed in Note 2 to Notes to the consolidated financial statements appearing elsewhere in this annual report.
Rearranged current paragraphs (1)

Current report — wording carried from elsewhere

Upon success in gaining regulatory approval from the FDA with OST-HER2 in Osteosarcoma, we intend to evaluate OST-HER2’s potential use, both alone and in combination with HER2 targeting antibodies such as Herceptin®, in other solid tumors including breast, esophageal and lung cancers. OST-HER2 has potential uses in both the prevention of metastases in solid tumors, and therapeutically against HER2-expressing solid tumors treated with HER targeting antibodies.