OS Therapies Inc

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. In the first quarter of 2025, we announced that our Phase IIb clinical trial achieved its primary endpoint with statistical significance. We believe the efficacy results, combined with the favorable safety profile and the unmet clinical need, support the potential for regulatory approval. We plan to request a Type B or Type C FDA meeting in the second quarter of 2025 to discuss the data and the path to a Biologics License Application (BLA). Subject to positive FDA feedback, we plan to submit a BLA with the FDA for approval to market the drug candidate shortly thereafter. 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. 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. In June 2025, we participated in a Type D meeting with the FDA and subsequently received positive written feedback regarding the design and endpoints of our Phase IIb trial of OST-HER2 to support a potential Biologics License Application (BLA). Based on this feedback, we have submitted a Breakthrough Therapy Designation request and, subject to continued positive regulatory guidance, plan to submit a BLA for OST-HER2 following our End of Phase 2 meeting with the FDA, anticipated in the third quarter of 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.

Previous wording

On December 24, 2024, we entered into a Securities Purchase Agreement (the “PIPE Purchase Agreement”) with certain institutional and accredited investors (collectively, the “Purchasers”), substantially all of whom are existing stockholders of our company, pursuant to which we agreed to issue and sell to the Purchasers immediately separable units (the “Units”), with each Unit being comprised of (i) one share of Series A Senior Convertible Preferred Stock, par value $0.001 per share (the “Series A Preferred Stock”), and (ii) a warrant to purchase one share of common stock (each, a “Series A Warrant” and such shares, the “Warrant Shares”), at a price per Unit of $4.00, for aggregate gross proceeds of not less than $6 million and not more than $10 million (the “PIPE Financing”). At two closings occurring on December 31, 2024 and January 14, 2025, we issued to the PIPE investors 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 Private Placement, before deducting transaction fees and other estimated Private Placement expenses, were approximately $7,103,000.

Current wording

On December 24, 2024, we entered into a Securities Purchase Agreement (the “PIPE Purchase Agreement”) with certain institutional and accredited investors (collectively, the “Purchasers”), substantially all of whom were existing stockholders of our company, pursuant to which we agreed to issue and sell to the Purchasers immediately separable units (the “Units”), with each Unit being comprised of (i) one share of Series Aseniorc onvertiblep referreds tock (“Series A Preferred Stock”)and (ii) a warrant to purchase one share of common stock (each, a “Series A Warrant” and such shares, the “Warrant Shares”), at a price per Unit of $4.00, for aggregate gross proceeds of not less than $6 million and not more than $10 million (the “PIPE Financing”). At two closings occurring on December 31, 2024 and January 14, 2025, we issued to the PIPE investors 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 PIPE Financing, before deducting transaction fees and other estimated PIPE Financing expenses, were approximately $7,103,000.

Previous wording

Brookline Capital Markets, a division of Arcadia Securities, LLC (“Brookline”), acted as exclusive placement agent for the issuance and sale of the securities in the PIPE Financing. Pursuant to the terms of a letter agreement, dated December 27, 2024, between the Company and Brookline (the “Placement Agency Agreement”), the Company 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 PIPE Financing to Purchasers other than certain Purchasers 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 PIPE Financing to Reduced Fee Purchasers, plus expenses; provided that Ceros Financial Services, Inc., Brookline’s selected dealer for the PIPE Financing (“Ceros”) is entitled to up to 33.3% of the Cash Fee.

Current wording

Brookline Capital Markets, a division of Arcadia Securities, LLC (“Brookline”), acted as exclusive placement agent for the issuance and sale of the securities in the PIPE Financing. Weagreed to pay Brookline an aggregate cash fee (the “Cash Fee”) equal to (i) 7% of the gross proceeds received byus from the sale of the securities in the PIPE Financing to Purchasers other than certain Purchasers identified on a schedule thereto (“Reduced Fee Purchasers”) plus (ii) 3% of the gross proceeds received byus from the sale of the securities in the PIPE Financing to Reduced Fee Purchasers, plus expenses; provided that Ceros Financial Services, Inc., Brookline’s selected dealer for the PIPE Financing (“Ceros”), is entitled to up to 33.3% of the Cash Fee.

Previous wording

In addition, the Company agreed to pay Brookline or its designee a fee in the form of warrants to purchase shares of common stock (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 Purchasers other than Reduced Fee Purchasers in the PIPE Financing 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 PIPE Financing; provided that, Ceros is entitled to up to 33.3% of the Agent Warrants. The terms of the Agent Warrants are substantially similar to the terms of the Series A Warrants. At two closings occurring on December 31, 2024 and January 14, 2025, (i) Brookline received an aggregate cash fee of $159,685 and the right to receive Agent Warrants initially exercisable for an aggregate of 39,918 shares of common stock, and (ii) Ceros received an aggregate cash fee of $79,723 and the right to receive Agent Warrants initially exercisable for an aggregate of 19,930 shares of common stock. Shortly following the second closing, we issued Brookline’s Agent Warrants and Ceros’ Agent Warrants to their respective designees in accordance with their instructions. Each of the holders of the Agent Warrants is affiliated with a broker-dealer regulated by the Financial Industry Regulatory Authority, Inc. These selling stockholders acquired their respective securities in the ordinary course of such selling stockholder’s business and, at the time of the acquisition of the shares to be resold pursuant to this prospectus, the selling stockholders had no agreements or understandings, directly or indirectly, with any person to distribute them.

Current wording

In addition, weagreed to pay Brookline or its designee a fee in the form of warrants to purchase shares of common stock (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 Purchasers other than Reduced Fee Purchasers in the PIPE Financing plus (ii) 3% of the number of shares of common stock initially issuable pursuant to the shares of Series A Preferred Stock issuedto the Reduced Fee Purchasers in the PIPE Financing; provided that, Ceros is entitled to up to 33.3% of the Agent Warrants. The terms of the Agent Warrants are substantially similar to the terms of the Series A Warrants. At two closings occurring on December 31, 2024 and January 14, 2025, (i) Brookline received an aggregate cash fee of $159,685 and the right to receive Agent Warrants initially exercisable for an aggregate of 39,918 shares of common stock, and (ii) Ceros received an aggregate cash fee of $79,723 and the right to receive Agent Warrants initially exercisable for an aggregate of 19,930 shares of common stock.

Previous wording

Our Acquisition of HER2 andLm-Related Assets

Current wording

Our Acquisition of HER2 and Lm-Related Assets

Previous wording

On April 9, 2025, pursuant to the terms of an Asset Purchase Agreement, dated as of January 28, 2025 (the “HER2 Purchase Agreement”), between us and Ayala Pharmaceuticals, Inc., a Delaware corporation formerly known as Advaxis, Inc. (“Ayala”), we completed the previously announced acquisition of theLm-based immune-oncology programs and related intellectual property assets (the “HER2 Assets”) from Ayala. The HER2 Assets include two investigational new drug (IND) filings with the FDA: (i) ADXS-503 for non-small cell lung cancer; and (ii) ADXS-504 for prostate cancer.

Current wording

On April 9, 2025, pursuant to the terms of an Asset Purchase Agreement, dated as of January 28, 2025 (the “HER2 Purchase Agreement”), between us and Ayala Pharmaceuticals, Inc., a Delaware corporation formerly known as Advaxis, Inc. (“Ayala”), we completed the acquisition of theLm-based immune-oncology programs and related intellectual property assets (the “HER2 Assets”) from Ayala. The HER2 Assets include two investigational new drug (IND) filings with the FDA: (i) ADXS-503 for non-small cell lung cancer; and (ii) ADXS-504 for prostate cancer.

Previous wording

In consideration for the purchase of the HER2 Assets, we agreed to assume certain specified liabilities and to pay an aggregate purchase price of $8,000,000, which was paid as follows: (i) $400,000 to Ayala ($150,000 of which was transferred upon signing of the HER2 Purchase Agreement and the remainder on the closing date); (ii) $100,000 to a third party on behalf of Ayala on the closing date; and (iii) $7,500,000 worth of shares of the our common stock, or 4,774,637 shares based on the volume-weighted average price of the Company’s common stock over the 30 trading days immediately preceding the closing date (the “Ayala Consideration Shares”).

Current wording

In consideration for the purchase of the HER2 Assets, we agreed to assume certain specified liabilities and to pay an aggregate purchase price of $8,000,000, which was paid as follows: (i) $400,000 to Ayala ($150,000 of which was transferred upon signing of the HER2 Purchase Agreement and the remainder on the closing date); (ii) $100,000 to a third party on behalf of Ayala on the closing date; and (iii) $7,500,000 worth of shares of our common stock, or 4,774,637 shares based on the volume-weighted average price of the Company’s common stock over the 30 trading days immediately preceding the closing date (the “Ayala Consideration Shares”).

Previous wording

Because the issuance of the Ayala Consideration Shares would require us to issue more than 19.99% of our outstanding common stock immediately prior to such issuance (the “NYSE Ownership Limitation”), we issued to Ayala (i) 2,164,215 shares of common stock (the “Ayala Initial Shares”), and (ii) a warrant to purchase 2,166,381 shares of common stock (the “Ayala Warrant” and the shares of common stock issuable thereunder, the “Ayala Warrant Shares”). Once we obtain stockholder approval in accordance with NYSE American LLC Company Guide Section 713, we will subsequently issue to Ayala the remaining 444,041 shares of common stock (the “Ayala Additional Consideration Shares”), except that, if at that time, the number of shares of common stock beneficially owned by Ayala would exceed 9.99% of the number of shares of our common stock then outstanding, Ayala has the right to require us to issue, in lieu of such shares, a warrant to purchase 444,041 on substantially the same terms of the Ayala Warrant.

Current wording

Because the issuance of the Ayala Consideration Shares would have required us to issue more than 19.99% of our outstanding common stock immediately prior to such issuance (the “NYSE Ownership Limitation”), we issued to Ayala (i) 2,164,215 shares of common stock, and (ii) a warrant to purchase 2,166,381 shares of common stock (the “Ayala Warrant” and the shares of common stock issuable thereunder, the “Ayala Warrant Shares”). Once we obtain stockholder approval in accordance with NYSE American LLC Company Guide Section 713, we will subsequently issue to Ayala the remaining 444,041 shares of common stock (the “Ayala Additional Consideration Shares”), except that, if at that time, the number of shares of common stock beneficially owned by Ayala would exceed 9.99% of the number of shares of our common stock then outstanding, Ayala has the right to require us to issue, in lieu of such shares, a warrant to purchase 444,041 on substantially the same terms of the Ayala Warrant.

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. The revaluation would result in material changes in fair value on a period by period basis. We have determined that the fair value of the warrant liability was a critical accounting estimate.

Current 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. 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.

Previous wording

***Revenue.***We did not recognize revenues for the three months ended March 31, 2025 and 2024.

Current wording

***Revenue.***We did not recognize revenues for the six months ended June 30, 2025 and 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

***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

Three Months Ended March 31, 2025 Compared to Three Months Ended March 31, 2024

Current wording

Three and Six Months Ended June 30, 2025 Compared to Three and Six Months Ended June 30, 2024

Previous wording

The following table summarizes our results of operations for the three months ended March 31, 2025 and 2024:

Current wording

The following table summarizes our results of operations for the three and six months ended June 30, 2025 and 2024:

Previous wording

***Research and Development Expenses.***Research and development expenses were approximately $1.3 million for the three months ended March 31, 2025 compared to approximately $0.4 million for the three months ended March 31, 2024. This increase was primarily due to an increase in vendor expenses associated with our Phase IIb clinical trial and a decrease in vendor expenses associated with out OST-tADC platform technology. The following table summarizes our research and development expenses for the three months ended March 31, 2025 and 2024:

Current wording

Research and development expenses were approximately $2.5 million for the three months ended June 30, 2025 compared to approximately $0.4 million for the three months ended June 30, 2024. This increase was primarily due to an increase in vendor expenses associated with our Phase IIb clinical trial, as we compile data to submit to various governmental agencies, and a decrease in vendor expenses associated with out OST-tADC platform technology.

Previous wording

For the three months ended March 31, 2025 and 2024, the direct research and development expenses related to OST-HER2 were primarily lab fees, vendor expenses and staff payroll fees. In 2025, such expenses were primarily lab fees and related clinical support of approximately $0.5 million attributed to our Phase IIb clinical trial preparation, advisor fees of $0.3 million, and legal costs of $0.1 million as we completed IND-enabling studies. OST-tADC related direct research and development expenses were approximately $0.04 million and $0.13 million for the three months ended March 31, 2025 and 2024, respectively.

Current wording

For the six months ended June 30, 2025 and 2024, the direct research and development expenses related to OST-HER2 were primarily lab fees, vendor expenses and staff payroll fees. In 2025, such expenses were primarily lab fees and related clinical support of approximately $1.0 million attributed to our Phase IIb clinical trial preparation, advisor fees of $1.9 million, and legal costs of $0.1 million as we completed IND-enabling studies. OST-tADC related direct research and development expenses were approximately $0.0 million and $0.0 million for the six months ended June 30, 2025 and 2024, respectively.

Previous wording

***General and Administrative Expenses.***General and administrative expenses for the three months ended March 31, 2025 were approximately $3.7 million compared to $0.3 million for the three months ended March 31, 2024. These expenses were primarily attributed to marketing costs and advisory fees associated with the PIPE Financing and equity line of credit.

Current wording

General and administrative expenses for the three months ended June 30, 2025 were approximately $2.3 million compared to $0.4 million for the three months ended June 30, 2024. These expenses were primarily attributed to marketing and investor relations costs and advisory fees associated with the PIPE Financing and equity line of credit.

Previous wording

***Interest Expense.***Interest expense for the three months ended March 31, 2025 was approximately $0 million compared to $0.8 million for the three months ended March 31, 2024.

Current wording

Interest expense for the three months ended June 30, 2025 was approximately $0.0 million compared to $0.8 million for the three months ended June 30, 2024.

Previous wording

The Series A preferred stock coupon dividend requirement of $31,250 for the three months ended March 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. We issued Series A convertible preferred stock and detachable warrants on December 31, 2024 and January 14, 2025. The adjustment of the fair value of the warrant liability was $1.1 million and $0 million for the three months ended March 31, 2025 and 2024, respectively.

Current wording

The Series A preferred stock coupon dividend requirement of $31,250 for the six months ended June 30, 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. We issued Series A convertible preferred stock and detachable warrants on December 31, 2024 and January 14, 2025. The adjustment of the fair value of the warrant liability was $1.4 million and $0.0 million for the six months ended June 30, 2025 and 2024, respectively.

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 three months ended March 31, 2025 and 2024, we reported a net loss of approximately $2.7 million and $1.5 million, respectively, and had an accumulated deficit of approximately $41 million and $38 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 product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of our product candidates. For the six months ended June 30, 2025 and 2024, we reported a net loss of approximately $8.4 million and $3.0 million, respectively, and had an accumulated deficit of approximately $47 million and $33 million, respectively. We expect to incur significant expenses at an increasing rate and increasing operating losses for the foreseeable future. For the three months ended June 30, 2025 and 2024, we reported a net loss of approximately $4.5 million and $1.6 million, respectively.

Previous wording

As of March 31, 2025 and December 31, 2024, we had cash of approximately $3.0 million and $5.5 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 31, 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 June 30, 2025 and December 31, 2024, we had cash of approximately $2.8 million and $5.5 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 and cash exercises of our warrants, as well as the sale of our common stock in our initial public offering, which have provided total gross proceeds of $37.1 million as of June 30, 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.

Previous wording

The following table summarizes our sources and uses of cash for each of the periods presented:

Current wording

The following table summarizes our sources and uses of cash for the six months ended June 30, 2025 and 2024:

Previous wording

During the three months ended March 31, 2025 and 2024, operating activities used approximately $3.4 million and $.6 million of cash, respectively, resulting from our net loss of approximately $3.9 million and $1.5 million, respectively, offset by net non-cash charges of approximately $0.7 million and $0.6 million, respectively, partially offset by net cash (used in) provided by changes in our operating assets and liabilities of approximately $(0.3) million and $0.2 million, respectively.

Current wording

During the six months ended June 30, 2025 and 2024, operating activities used approximately $5.9 million and $1.5 million of cash, respectively, resulting from our net loss of approximately $8.4 million and $3.0 million, respectively, offset by net non-cash charges of approximately $1.4 million and $1.1 million, respectively, partially offset by net cash provided by changes in our operating assets and liabilities of approximately $1.2 million and $0.4 million, respectively.

Previous wording

Net cash provided by changes in our operating assets and liabilities for the three ended March 31, 2025 and 2024 consisted primarily of an increase (decrease) in accounts payable of approximately $(0.05) million and $0.04 million, respectively, an increase (decrease) in accrued interest of approximately $0 million and $0.25 million, respectively, and a change in accrued payroll of approximately $(0.1) million and $(0.05) million, respectively. The change in accrued expenses of approximately $(0.15) million and $(0.0) million was a significant portion of the use.

Current wording

Net cash provided by changes in our operating assets and liabilities for the six months ended June 30, 2025 and 2024 consisted primarily of an increase (decrease) in accounts payable of approximately $1.1 million and $(0.05) million, respectively, an increase in accrued interest of approximately $0.0 million and $0.5 million, respectively, and a change in prepaid expenses of approximately $0.4 million and $(0.0) million, respectively. The change in accrued expenses of approximately $(0.15) million and $0.3 million was a portion of the use.

Previous wording

Non-cash charges for the three months ended March 31, 2025 and 2024 were primarily the result of the changes in the fair value of our warrant liability combined with our common stock shares issued for service and our stock-based compensation of approximately $0.7 million and $0.6 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

Non-cash charges for the six months ended June 30, 2025 and 2024 were primarily the result of the changes in the fair value of our warrant liability of $(1.4) million and $0.0 million, respectively, combined with our common stock shares issued for service and our stock-based compensation of approximately $2.7 million and $0.0 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.

Previous wording

During the three months ended March 31, 2025 and 2024, net cash used by investing activities was approximately $0.2 million and $0 million, respectively.

Current wording

During the six months ended June 30, 2025 and 2024, net cash used in investing activities was approximately $0.4 million and $0.0 million, respectively.

Previous wording

For the three months ended March 31, 2025 and 2024, net cash provided by financing activities was approximately $1.1 million and $0.7 million, respectively.

Current wording

For the six months ended June 30, 2025 and 2024, net cash provided by financing activities was approximately $3.5 million and $1.6 million, respectively. For the six months ended June 30, 2025, we saw funds raised from our Series A securities offering of $1.1 million and our warrant inducement exercise offering of $2.5 million.

Previous wording

***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 March 31, 2025, 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.

Current wording

***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. For the six months ended June 30, 2025 and for the year ended December 31, 2024, no payments were made. A $400,000 payment was made to Ayala, together with payment of stock consideration, in connection with our purchase of the HER2 Assets on April 9, 2025, terminating this license agreement. The payment schedule for milestones and corresponding payment amounts were as set forth below.

Previous wording

***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 $2,436,928. For the three months ended March 31, 2025 and 2024, we paid $0 and $86,687, 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.

Current wording

***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 $2,436,928. For the six months ended June 30, 2025 and 2024, we paid $0 and $86,687, 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 wording

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 March 31, 2025, the balance due to George Clinical was $148,587.

Current wording

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 June 30, 2025 and 2024, the balance due to George Clinical was $0 and $663,622, respectively. The services agreement has terminated on its terms.