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MUSTANG BIO, INC.

For the period ended Jun 30, 2025. Filed Aug 8, 2025.

View on SEC.gov

About this filing

A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.

Jun 30, 2025 · Filed Aug 8, 2025

MBIO$0.39+0.2%Stored close · as of Nov 6, 2026

What changed in Management’s Discussion and Analysis?

Read the current filing

Previous report: 10-Q

Period ended 2025-03-31; filed 2025-05-14.

0001558370-25-007736

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Current report: 10-Q

Period ended 2025-06-30; filed 2025-08-08.

0001558370-25-010920

Item 2. 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 79 previous paragraphs and 81 current paragraphs.

41 unchanged; 22 reworded; 14 added; 15 removed; 1 previous and 4 current paragraphs rearranged.

Tables are not compared: 6 previous and 18 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 (14)

Current report

In July 2025, certain investors from the February 2025 Equity Offering (as defined below) exercised outstanding pre-funded and Series C-2 warrants resulting in us issuing approximately 2.9 million shares of our common stock and receiving proceeds of approximately $7.1 million.

Current report

For the three months ended June 30, 2024, we incurred impairment charges of $2.6 million attributable to our assessment of the recoverability of the asset group consisting of leasehold improvements and associated right-of-use asset. No impairment was recorded in the three months ended June 30, 2025.

Current report

For the six months ended June 30, 2024, we incurred impairment charges of $2.6 million attributable to our assessment of the recoverability of the asset group consisting of leasehold improvements and associated right-of-use asset. No impairment was recorded in the six months ended June 30, 2025.

Current report

For the six months ended June 30, 2025, and 2024, general and administrative expenses were $2.0 million and $3.0 million, respectively. The decrease of approximately $1.0 million is primarily attributed to a $0.2 million decrease in personnel costs, $0.3 million decrease in legal and patent protection expenses, $0.3 million decrease in consulting expenses, and a $0.2 million decrease across various other general and administrative expenses.

Current report

For the six months ended June 30, 2025, and 2024, total other income was $0.2 million and $0.4 million, respectively. The decrease of approximately $0.2 million reflects a decrease of other income of approximately $0.3 million related to the non-repeat gain on the termination of the Mercantile Center lease in June 2024 offset by an increase in interest income of approximately $0.2 million.
Removed paragraphs (15)

Previous report

On January 15, 2025, we filed a certificate of amendment (the “Amendment”) to our amended and restated certificate of incorporation, as amended, with the Secretary of State of the State of Delaware, to effect a 1-for-50 reverse stock split of our issued and outstanding common stock, without any change to par value. The Amendment became effective upon such filing. No fractional shares were issued in connection with the reverse stock split, as all fractional shares were rounded down to the next whole share. The reverse stock split was intended to bring the Company into compliance with the continued listing requirements of The Nasdaq Stock Market LLC (“Nasdaq”).

Previous report

On February 10, 2025, we entered into a Bill of Sale and Surrender Agreement (the “Sale/Surrender Agreement”), effective as of January 31, 2025, with AbbVie Bioresearch Center Inc., a Delaware corporation (“AbbVie”). We were the tenant in the leased premises located at 377 Plantation Street, Worcester, Massachusetts (the “Premises”) under a Lease Agreement, dated as of October 27, 2017 (the “Lease”) with WCS - 377 Plantation Street, Inc., a Massachusetts nonprofit corporation (the “Landlord”). In connection with the entrance into the Sale/Surrender Agreement, we also entered into an Escrow Agreement, dated February 10, 2025 (the “Escrow Agreement”), with Bowditch & Dewey, LLP, as escrow agent (the “Escrow Agent”), pursuant to which the Escrow Agent would disburse the Purchase Price (defined herein) to us pursuant to the terms of the Escrow Agreement.

Previous report

Pursuant to the terms of the Sale/Surrender Agreement, AbbVie agreed to purchase from us, and we agreed to sell and convey to AbbVie, certain furniture, fixtures and equipment (“FF&E”), which we classified as held for sale as of December 31, 2024, located in the Premises and other items as set forth in the Sale/Surrender Agreement for a purchase price of $1.0 million (the “Purchase Price”). AbbVie also agreed to lease the Premises from the Landlord following the termination of the Lease pursuant to a First Amendment to Lease Agreement, dated as of February 7, 2025.

Previous report

The closing of the transactions described above occurred on February 21, 2025, with AbbVie’s issuance of an Acceptance Notice (as defined in the Sale/Surrender Agreement) to us stating that a Sufficient Percentage (as defined in the Sale/Surrender Agreement) of the FF&E items listed in the Sale/Surrender Agreement are present in the Premises and functional for their intended purpose without the need for repair or replacement. On February 25, 2025, as a result of the issuance of the Acceptance Notice, pursuant to the terms of the Escrow Agreement, the Escrow Agent released the Purchase Price to us. On February 27, 2025, we announced the relocation of our corporate headquarters to 95 Sawyer Road, Waltham, Massachusetts.

Previous report

On March 13, 2024, we received a deficiency letter (the “Letter”) from the Listing Qualifications Department (the “Staff”) of Nasdaq notifying us that we were not in compliance with the minimum stockholders’ equity requirement for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(b)(1) (the “Equity Rule”). The Equity Rule requires companies listed on the Nasdaq Capital Market to maintain stockholders’ equity of at least $2.5 million (or, in the alternative, a market value of listed securities of $35 million or net income from continued operations of $500,000 in the most recently completed fiscal year or in two of the last three most recently completed fiscal years).

Previous report

On May 16, 2024, we received a second notice (the “Second Letter”) from the Staff of Nasdaq indicating that the bid price of our common stock had closed below $1.00 per share for 31 consecutive business days and, as a result, we were not in compliance with Nasdaq Listing Rule 5550(a)(2), which sets forth the minimum bid price requirement for continued listing on the Nasdaq Capital Market (the “Bid Price Rule”). The Second Letter from Nasdaq had no immediate effect on the listing of our common stock on Nasdaq. Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), we were afforded a 180-calendar day grace period, or until November 12, 2024, to regain compliance with the Bid Price Rule. Compliance can be achieved by evidencing a closing bid price of at least $1.00 per share for a minimum of ten consecutive business days (but generally not more than 20 consecutive business days) during the 180-calendar day grace period.

Previous report

By decision dated November 8, 2024, a Nasdaq Hearings Panel (the “Panel”) granted our request for an extension to evidence compliance with all applicable criteria for continued listing on the Nasdaq Capital Market, including the Bid Price Rule, through January 31, 2025, and the Equity Rule through February 18, 2025.

Previous report

On January 15, 2025, we effected the reverse stock split described above, which was intended to bring us into compliance with the Bid Price Rule. On February 10, 2025, we were notified by the Staff that we had regained compliance with the Bid Price Rule.

Previous report

On February 10, 2025, we completed a best-efforts public offering for net proceeds of approximately $6.8 million. Following the closing, we provided an updated forecast to the Panel evidencing compliance with the Equity Rule. On February 26, 2025, we were notified by the Staff that we had regained compliance with the Equity Rule and are subject to mandatory monitoring by the Panel for one year.
Reworded paragraphs (22)

Previous wording

On November 7, 2024, we announced that the FDA granted Orphan Drug Designation to Mustang for MB-108, a herpes simplex virus type 1 (“HSV-1”) oncolytic virus, for the treatment of malignant glioma. The Orphan Drug Designation provides certain incentives, such as tax credits toward the cost of clinical trials upon approval and prescription drug user fee waivers. If a product receives Orphan Drug Status from the FDA, that product is entitled to seven years of market exclusivity for the disease in which it has Orphan Drug designation, which is independent from intellectual property protection.

Current wording

On November 7, 2024, we announced that the FDA granted Orphan Drug Designation to Mustang for MB-108, a herpes simplex virus type 1 (“HSV-1”) oncolytic virus, for the treatment of malignant glioma. On July 7, 2025, we announced that the FDA granted Orphan Drug Designation to Mustang for MB-101, IL13Ra2-targeted CAR T-cells, for the treatment of recurrent diffuse and anaplastic astrocytoma (astrocytomas) and glioblastoma. The Orphan Drug Designation provides certain incentives, such as tax credits toward the cost of clinical trials upon approval and prescription drug user fee waivers. If a product receives Orphan Drug Status from the FDA, that product is entitled to seven years of market exclusivity for the disease in which it has Orphan Drug Designation, which is independent from intellectual property protection.

Previous wording

We are currently exploring with COH and Nationwide the possibility of conducting an investigator-sponsored single-institution trial under the COH IND to treat patients with IL13Rα2+ recurrent GBM and high-grade astrocytoma with MB-109 that could potentially be initiated in the first quarter of 2026. Because cell processing for MB-101 will revert back to COH – where the product continues to be manufactured today for other investigator-sponsored clinical trials being conducted by COH in malignant brain tumors (ClinicalTrials.gov Identifiers: NCT04003649, NCT04661384, NCT04510051), we believe that it is reasonable to assume that the FDA will not require a lead-in cohort, wherein patients would have to be treated with MB-101 alone prior to dual MB-108 administration. Should this, indeed, be the case, the first patient enrolled will receive the combination of MB-101 and MB-108, which will represent a considerable savings of time and money – as well as afford the potential benefit of both therapies to every patient treated on study.

Current wording

We are currently exploring with COH and Nationwide the possibility of conducting an investigator-sponsored single-institution trial under the COH IND to treat patients with IL13Rα2+ recurrent GBM and high-grade astrocytoma with MB-109 that could potentially be initiated in the first quarter of 2026. Because cell processing for MB-101 will revert back to COH – where the product continues to be manufactured today for other investigator-sponsored clinical trials being conducted by COH in malignant brain tumors (ClinicalTrials.gov Identifiers: NCT04003649, NCT04661384, NCT04510051), we believe that it is reasonable to assume that the FDA will not require a lead-in cohort, wherein a cohort of patients would have to be treated with MB-101 alone prior to treatment of subsequent cohorts with the combination of MB-108 followed by MB-101. Should this, indeed, be the case, the first patient enrolled will receive combination therapy, which will represent a considerable savings of time and money – as well as afford the potential benefit of both therapies to every patient treated on study.

Previous wording

All share and per share amounts of our common stock listed in this Form 10-Q have been adjusted to give effect to the reverse stock split.

Current wording

All share and per share amounts of our common stock listed in this Form 10-Q have been adjusted to give effect to our 1-for-50 reverse stock split effective January 15, 2025.

Previous wording

On February 5, 2025, we commenced a best efforts public offering (the “February 2025 Offering”) of an aggregate of (i) 495,000 shares (the “Shares”) of our common stock, (ii) pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to an aggregate of 2,162,807 shares of common stock (the “Pre-Funded Warrant Shares”), (iii) Series C-1 warrants (the “Series C-1 Warrants”) to purchase up to an aggregate of 2,657,807 shares of common stock (the “Series C-1 Warrant Shares”), and (iv) Series C-2 warrants (the “Series C-2 Warrants,” and together with the Series C-1 Warrants, the “Warrants”) to purchase up to an aggregate of 2,657,807 shares of common stock (the “Series C-2 Warrant Shares,” and together with the Series C-1 Warrant Shares, the “Warrant Shares”). Each Share or Pre-Funded Warrant was sold together with one Series C-1 Warrant to purchase one share of common stock and one Series C-2 Warrant to purchase one share of common stock. The combined public offering price for each Share and accompanying Warrants was $3.01, and the combined public offering price for each Pre-Funded Warrant and accompanying Warrants was $3.0099.

Current wording

On February 5, 2025, we commenced a best efforts public offering (the “February 2025 Equity Offering”) of an aggregate of (i) 495,000 shares (the “Shares”) of our common stock, (ii) pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to an aggregate of 2,162,807 shares of common stock (the “Pre-Funded Warrant Shares”), (iii) Series C-1 warrants (the “Series C-1 Warrants”) to purchase up to an aggregate of 2,657,807 shares of common stock (the “Series C-1 Warrant Shares”), and (iv) Series C-2 warrants (the “Series C-2 Warrants,” and together with the Series C-1 Warrants, the “Warrants”) to purchase up to an aggregate of 2,657,807 shares of common stock (the “Series C-2 Warrant Shares,” and together with the Series C-1 Warrant Shares, the “Warrant Shares”). Each Share or Pre-Funded Warrant was sold together with one Series C-1 Warrant to purchase one share of common stock and one Series C-2 Warrant to purchase one share of common stock. The combined public offering price for each Share and accompanying Warrants was $3.01, and the combined public offering price for each Pre-Funded Warrant and accompanying Warrants was $3.0099.

Previous wording

The net proceeds of the Offering, after deducting the fees and expenses of the Placement Agent, and other offering expenses payable by the Company, but excluding the net proceeds, if any, from the exercise of the Warrants, was approximately $6.8 million. The Company intends to use the net proceeds from the Offering for working capital and general corporate purposes. The February 2025 Offering closed on February 10, 2025.

Current wording

The net proceeds of the Offering, after deducting the fees and expenses of the Placement Agent, and other offering expenses payable by us, but excluding the net proceeds, if any, from the exercise of the Warrants, was approximately $6.8 million. We intend to use the net proceeds from the offering for working capital and general corporate purposes. The February 2025 Equity Offering closed on February 10, 2025.

Previous wording

During the three months ended March 31, 2025, we issued approximately 54,000 shares of common stock at an average price of $11.55 for gross proceeds of $0.6 million under the ATM Agreement. In connection with these sales, we paid aggregate fees of approximately $27,000.

Current wording

During the six months ended June 30, 2025, we issued approximately 54,000 shares of common stock at an average price of $11.55 for gross proceeds of $0.6 million under the ATM Agreement. In connection with these sales, we paid aggregate fees of approximately $27,000.

Previous wording

Our discussion and analysis of our financial condition and results of operations are based on our financial statements, which we have prepared in accordance with accounting principles generally accepted in the United States. Applying these principles requires our judgment in determining the appropriateness of acceptable accounting principles and methods of application in diverse and complex economic activities. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of expenses, assets and liabilities, and related disclosure of contingent assets and liabilities. We base our estimates on historical experience and other assumptions that we believe are reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.

Current wording

judgment in determining the appropriateness of acceptable accounting principles and methods of application in diverse and complex economic activities. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of expenses, assets and liabilities, and related disclosure of contingent assets and liabilities. We base our estimates on historical experience and other assumptions that we believe are reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.

Previous wording

During the three months ended March 31, 2025, there were no new accounting pronouncements or updates to recently issued accounting pronouncements disclosed in the 2024 Form 10-K that are expected to materially affect the Company’s present or future financial statements.

Current wording

During the six months ended June 30, 2025, there were no new accounting pronouncements or updates to recently issued accounting pronouncements disclosed in the 2024 Form 10-K that are expected to materially affect our present or future financial statements.

Previous wording

For the three months ended March 31, 2025, and 2024, general and administrative expenses were $1.2 million and $1.4 million, respectively. The decrease of approximately $0.2 million is primarily attributed to a $0.2 million decrease in consulting costs and $0.2 million decrease in professional services including legal and patent protection expenses, offset by $0.2 million increase non-cash stock-based compensation expenses, including the equity fee to Fortress.

Current wording

For the three months ended June 30, 2025, and 2024, general and administrative expenses were $0.8 million and $1.5 million, respectively. The decrease of approximately $0.7 million is primarily attributed to a $0.3 million decrease in personnel related expenses, $0.2 million decrease in non-cash stock-based compensation expenses, including the equity fee to Fortress, $0.1 million decrease in consulting costs and $0.1 million decrease in professional services including legal and patent protection expenses.

Previous wording

For the three months ended March 31, 2025, and 2024, other income was $0.1 million and $40,000, respectively. The increase of approximately $60,000 reflects an increase in interest income.

Current wording

For the three months ended June 30, 2025, and 2024, other income was $0.1 million and $0.3 million, respectively. The decrease of approximately $0.2 million reflects a decrease in other income of approximately $0.3 million related to the non-repeat gain on the termination of the Mercantile Center lease in June 2024, offset by an increase in interest income of approximately $0.1 million.

Previous wording

For the three months ended March 31, 2025 and 2024, research and development expenses were approximately $(1.0) million and $3.8 million, respectively. The decrease of approximately $4.8 million is primarily attributed to actions taken in 2024, including the reduction in the workforce, closing the MB-106 clinical trial, and the termination of our transaction with uBriGene. These activities resulted in decreases in the following expenses:

Current wording

For the six months ended June 30, 2025 and 2024, research and development expenses were approximately $(0.9) million and $8.2 million, respectively. The decrease of approximately $9.0 million is primarily attributed to actions taken in 2024, including the reduction in the workforce, closing the MB-106 clinical trial, and the termination of our transaction with uBriGene. These activities resulted in decreases in the following expenses:

Previous wording

Additionally, we have been actively negotiating settlements of aged payables, and recognized savings of approximately $0.7 million and recognized a net gain of approximately $0.4 million due to the termination of the Plantation Street Facility lease, which resulted in a credit for research and development expenses for the three months ended March 31, 2025. This credit is not indicative of our research and development expenses going forward.

Current wording

Additionally, we have been actively negotiating settlements of aged payables, and recognized savings of approximately $0.8 million and recognized a net gain of approximately $0.4 million due to the termination of the Plantation Street Facility lease, which resulted in a credit for research and development expenses for the six months ended June 30, 2025. This credit is not indicative of our research and development expenses going forward.

Previous wording

At March 31, 2025, we had cash and cash equivalents of $14.2 million. We have funded our operations to date primarily with the proceeds from various public and private offerings of our common stock. We have incurred substantial operating losses and expect to continue to incur significant operating losses for the foreseeable future and may never become profitable. We will continue to seek additional funding through corporate partnerships and capital markets fundraising. As of March 31, 2025, we had an accumulated deficit of $396.9 million.

Current wording

At June 30, 2025, we had cash and cash equivalents of $12.7 million. We have funded our operations to date primarily with the proceeds from various public and private offerings of our common stock. We have incurred substantial operating losses and expect to continue to incur significant operating losses for the foreseeable future and may never become profitable. We will continue to seek additional funding through corporate partnerships and capital markets fundraising. As of June 30, 2025, we had an accumulated deficit of $397.6 million.

Previous wording

manufacturing and supply. These contracts typically do not contain minimum purchase commitments and are generally terminable by us upon written notice. Payments due upon termination or cancelation/delay consist of payments for services provided or expenses incurred, including non-cancelable obligations of our service providers, up to the date of cancellation; in certain cases, our contractual arrangements with CROs and CMOs include cancelation and/or delay fees and penalties.

Current wording

We enter into contracts in the normal course of business with licensors, clinical research organizations (“CROs”), contract manufacturing organizations (“CMOs”) and other third parties for the procurement of various products and services, including without limitation biopharmaceutical development, biologic assay development, commercialization, clinical and preclinical development, clinical trials management, pharmacovigilance and manufacturing and supply. These contracts typically do not contain minimum purchase commitments and are generally terminable by us upon written notice. Payments due upon termination or cancelation/delay consist of payments for services provided or expenses incurred, including non-cancelable obligations of our service providers, up to the date of cancellation; in certain cases, our contractual arrangements with CROs and CMOs include cancelation and/or delay fees and penalties.

Previous wording

During the three months ended March 31, 2025, there were no material changes in our contractual obligations and commitments, as described in our 2024 Form 10-K.

Current wording

During the three and six months ended June 30, 2025, there were no material changes in our contractual obligations and commitments, as described in our 2024 Form 10-K.

Previous wording

Cash Flows for the Three Months Ended March 31, 2025 and 2024

Previous wording

Net cash used in operating activities was $1.4 million for the three months ended March 31, 2025, compared to $5.3 million for the three months ended March 31, 2024.

Current wording

Net cash used in operating activities was $2.7 million for the six months ended June 30, 2025, compared to $7.7 million for the six months ended June 30, 2024.

Previous wording

Net cash used in operating activities for thethree months ended March 31, 2025, was primarily due to approximately $0.2 million in net loss, $1.1 million change in operating assets and liabilities, and $0.4 million gain on the termination of the Plantation Street Facility lease, partially offset by $0.3 million of non-cash items, primarily related to the $0.2 million equity fee to Fortress for financing activity.

Current wording

Net cash used in operating activities for thesix months ended June 30, 2025, was primarily due to approximately $0.9 million in net loss, $1.8 million change in operating assets and liabilities, and $0.4 million gain on the termination of the Plantation Street Facility lease, partially offset by $0.3 million of non-cash items, primarily related to the $0.2 million equity fee to Fortress for financing activity.

Previous wording

Net cash used in operating activities for thethree months ended March 31, 2024, was primarily due to approximately$5.2 million in net loss, $0.9 million change in operating assets and liabilities, partially offset by $0.1 million of non-cash stock compensation expenses, $0.3 million of depreciation, and $0.4 million from amortization of operating lease right-of-use assets.

Current wording

Net cash used in operating activities for thesix months ended June 30, 2024, was primarily due to approximately$13.4 million in net loss, partially offset by $5.7 million of non-cash items, primarily related to the $2.6 million asset impairment charge and a $3.1 million change in operating assets and liabilities.

Previous wording

During thethree months ended March 31, 2025, net cash provided by investing activities was $1.2 million, which primarily reflects the proceeds from the sale of equipment to AbbVie. No cash was used in or provided by investing activities during the three months ended March 31, 2024.

Current wording

During thesix months ended June 30, 2025, net cash provided by investing activities was $1.2 million, which primarily reflects the proceeds from the sale of equipment to AbbVie. No cash was used in or provided by investing activities during the six months ended June 30, 2024.

Previous wording

Net cash provided by financing activities was $7.6 million during thethree months ended March 31, 2025, primarily reflecting the proceeds from the February 2025 Offering and the ATM Agreement.

Current wording

Net cash provided by financing activities was $7.4 million during thesix months ended June 30, 2025, primarily reflecting the proceeds from the February 2025 Equity Offering and the ATM Agreement.

Previous wording

Net cash provided by financing activities was $49,000 during the three months ended March 31, 2024, reflecting proceeds from the issuance of shares related to the ESPP.

Current wording

Net cash provided by financing activities was $5.3 million during the six months ended June 30, 2024, primarily reflecting proceeds from the May 2024 Offering and June 2024 Offering.
Rearranged current paragraphs (4)

Current report — wording carried from elsewhere

Our discussion and analysis of our financial condition and results of operations are based on our financial statements, which we have prepared in accordance with accounting principles generally accepted in the United States. Applying these principles requires our

Current report — wording carried from elsewhere

For the three months ended June 30, 2025 and 2024, research and development expenses were approximately $0.1 million and $4.4 million, respectively. The decrease of approximately $4.3 million is primarily attributed to actions taken in 2024, including the reduction

Current report — wording carried from elsewhere

in the workforce, closing the MB-106 clinical trial, and the termination of our transaction with uBriGene. These activities resulted in decreases in the following expenses:

Current report — wording carried from elsewhere

Additionally, we have been actively negotiating settlements of aged payables, and recognized savings of approximately $0.1 million.
Rearranged previous paragraphs (1)

Previous report — wording carried elsewhere

We enter into contracts in the normal course of business with licensors, CROs, contract manufacturing organizations (CMOs) and other third parties for the procurement of various products and services, including without limitation biopharmaceutical development, biologic assay development, commercialization, clinical and preclinical development, clinical trials management, pharmacovigilance and