S-1/A: Abpro Holdings Faces Going Concern, Nasdaq Delisting Amid Funding Efforts

Abpro Holdings, a preclinical biotechnology company, filed an S-1/A to register shares for resale under a $50 million equity purchase agreement, while facing substantial doubt about its ability to continue as a going concern and multiple Nasdaq delisting notices.

Summary

• Abpro Holdings is a biotechnology company focused on developing next-generation antibody therapeutics for immuno-oncology and ophthalmology, leveraging its proprietary DiversImmune and MultiMab™ platforms.
• The company has incurred significant recurring losses, with a net loss of $8.5 million for the nine months ended September 30, 2025, and an accumulated deficit of $124.6 million as of that date.
• Management has concluded there is substantial doubt about the company's ability to continue as a going concern within one year due to ongoing operating losses and insufficient cash to fund operations.
• Abpro Holdings received multiple notices from Nasdaq regarding non-compliance with minimum bid price, market value of publicly held shares (MVPHS), and market value of listed securities (MVLS) requirements.
• A 1-for-30 reverse stock split was effected on October 31, 2025, to address Nasdaq's minimum bid price requirement.
• The company has a Standby Equity Purchase Agreement (SEPA) with YA II PN, Ltd. for up to $50 million in equity purchases, with 9,775,017 shares registered for resale under this prospectus.
• Lead product candidates, ABP-102 (HER2+ solid tumors) and ABP-201 (wet age-related macular degeneration and diabetic macular edema), are in preclinical development, with clinical trials expected to initiate in the first half of 2026 and second half of 2026, respectively.
• The company is in breach of its license agreement with MedImmune/AstraZeneca related to ABP-201, having missed target dates for IND application (July 2021) and Phase II commencement (December 2022).
• Abpro Holdings has entered into collaboration agreements with Celltrion Inc. for ABP-102, Abpro Bio International, Inc. for ABP-201, and Nanjing Chia Tai Tianqing Pharmaceutical Co., Ltd (NJCTTQ) for ABP-150.
• The company has identified material weaknesses in its internal control over financial reporting, including inadequate segregation of duties and lack of formal written policies.
• A restatement of prior period financial statements was necessary due to accounting errors related to understatement of liabilities under a license agreement.

Sentiment

Score: 2

Explanation: The company faces severe financial distress, including a going concern warning, significant accumulated deficit, and insufficient cash. Multiple Nasdaq delisting threats and ongoing legal disputes add to the instability. While the product pipeline shows potential, it is in very early preclinical stages, and future funding is highly uncertain, posing substantial risks to investors.

Positives

• Proprietary DiversImmune and MultiMab™ antibody discovery and engineering platforms are designed to generate next-generation antibody therapeutics.
• Strategic partnerships with global biopharmaceutical companies like Celltrion Inc. (for ABP-102) and Abpro Bio International, Inc. (for ABP-201) provide development and commercialization support.
• ABP-102 is designed as a next-generation T-cell engager with bivalent HER2 binding and affinity-tuned CD3 binding for selective tumor targeting and reduced off-tumor toxicity.
• ABP-201 is a dual-targeting antibody for VEGF and ANG-2, designed for high binding capacity and longer ocular half-life, potentially allowing less frequent dosing than current Wet AMD/DME treatments.
• The global HER2+ cancer market is forecast to grow to $12.1 billion by 2030, and the global wet age-related macular degeneration (AMD) market is projected to reach $10.4 billion by 2024.
• The company has an experienced leadership team with significant industry know-how in antibody discovery, clinical development, and corporate finance.
• The Standby Equity Purchase Agreement (SEPA) with YA II PN, Ltd. provides access to up to $50 million in aggregate gross proceeds for working capital and general corporate purposes.

Negatives

• The company has a history of significant operating losses, with a net loss of $8.5 million for the nine months ended September 30, 2025, and an accumulated deficit of $124.6 million.
• Management has concluded there is substantial doubt about the company's ability to continue as a going concern within one year due to insufficient cash and ongoing operating losses.
• The company received multiple Nasdaq delisting notices for failing to meet minimum bid price, market value of publicly held shares ($15 million), and market value of listed securities ($50 million) requirements.
• A 1-for-30 reverse stock split was implemented to regain Nasdaq compliance, which may decrease liquidity and not attract new investors.
• The company is a preclinical stage biopharmaceutical company with no products on the market and has never generated revenue from product sales.
• The company is in breach of its license agreement with MedImmune/AstraZeneca for ABP-201, having missed key development milestones, which could lead to termination of the license.
• The Common Stock being registered for resale (9,775,017 shares) represents approximately 360% of the total outstanding Common Stock as of November 28, 2025, posing a significant dilution risk.
• Material weaknesses in internal control over financial reporting have been identified, including inadequate segregation of duties and lack of formal written policies.
• The company was required to restate prior period financial statements due to accounting errors, affecting investor confidence and raising reputational issues.
• A lawsuit from a CRO vendor resulted in a judgment of approximately $700,000 against the company.
• MSK terminated an exclusive license agreement due to the company's failure to fulfill payment obligations, with MSK demanding approximately $1.2 million.

Risks

• Uncertainties around the ability to raise additional capital raise substantial doubt about the ability to continue as a going concern, including drug development.
• Drug development is a highly uncertain undertaking and involves a substantial degree of risk, with product candidates in early stages and never tested in humans.
• The market may not be receptive to product candidates based on novel therapeutic modalities, potentially preventing revenue generation from sales or licensing.
• Substantial additional funds will be needed to advance product candidates, and there is no guarantee of sufficient future funding.
• Breach of the license agreement with MedImmune/AstraZeneca could lead to termination and loss of intellectual property rights necessary for ABP-201 development.
• Collaborations with third parties may not be successful, potentially hindering the capitalization on market potential or leading to termination of agreements and loss of milestone/royalty payments.
• Reliance on third parties for preclinical studies and clinical trials means less control over timing and quality, potentially leading to delays or adverse effects.
• Reliance on third-party manufacturing and supply partners for preclinical and clinical development materials poses risks of limited, interrupted, or unsatisfactory supply.
• Competition from larger, better-funded entities developing similar product candidates or novel technologies could adversely affect the ability to commercialize products.
• Inability to attract and retain qualified key management, technical personnel, and employees would impair the ability to implement the business plan.
• Litigation and legal proceedings may substantially increase costs and harm the business.
• Inability to obtain or protect intellectual property rights related to technology and product candidates, or inadequate intellectual property rights, could impair competitive effectiveness.
• Patent terms may be inadequate to protect competitive position for an adequate amount of time.
• Changes in U.S. patent law or the patent law of other countries could diminish the value of patents.
• Third parties may initiate legal proceedings alleging infringement of intellectual property rights.
• Inability to protect the confidentiality of trade secrets would harm the business and competitive position.
• Clinical development involves a lengthy and expensive process with an uncertain outcome, and earlier results may not predict future trial results.
• Inability to obtain U.S. or foreign regulatory approval would prevent commercialization of product candidates.
• Ongoing regulatory obligations and continued regulatory review, even if approval is received, may result in significant additional expense and potential market withdrawal.
• Healthcare legislative reform measures may have a material adverse effect on business and results of operations.
• Failure to comply with healthcare laws and regulations could lead to enforcement actions and harm reputation.
• Subject to U.S. and foreign anti-corruption and anti-money laundering laws, non-compliance can lead to criminal/civil liability.
• Internal computer systems or those of contractors may fail or suffer security breaches, disrupting product development.
• Failure to comply with environmental and health and human safety laws could adversely affect the business.
• Adverse effects from natural disasters on operations or third-party manufacturers.
• The Charter and Bylaws designate Delaware courts as the sole forum for disputes, potentially limiting stockholders' ability to obtain a favorable judicial forum.
• Anti-takeover provisions in governing documents and Delaware law could make an acquisition more difficult.
• Management team may not successfully or efficiently manage the transition to being a public company, incurring increased expenses and administrative burdens.
• Material weaknesses in internal control over financial reporting could affect timely and reliable financial reports and weaken investor confidence.
• Restatement of prior period financial statements may affect investor confidence and raise reputational issues.
• Reduced SEC reporting requirements as an emerging growth company may make shares less attractive to investors.
• An active market for securities may not develop, adversely affecting liquidity and price.
• Failure to meet Nasdaq's continued listing requirements could result in delisting.
• The market price for Common Stock may decline due to various factors.
• Stockholders may experience dilution in the future from equity issuances.
• Warrants may expire worthless or their terms may be amended.
• Sales of a substantial amount of Common Stock by current stockholders could cause the price to fall.
• Inability to predict the actual number of shares sold under the SEPA or the actual gross proceeds, and potential lack of access to the full amount available under the SEPA.
• Management will have broad discretion over the use of net proceeds from SEPA sales, which may not be invested successfully.

Future Outlook

The company expects to initiate Phase 1/2 clinical trials for ABP-102 in the first half of 2026 and Phase 1 clinical trials for ABP-201 in the second half of 2026, contingent on future funding availability. It plans to continue fundraising through equity and debt financings, collaboration agreements, and research grants to meet its operational needs beyond the next 12 months. The company also intends to expand its pipeline of CD3-targeting T-cell engagers and other multi-specific antibody constructs.

Management Comments

• Miles Suk was appointed Chief Executive Officer and Chairman of the Board in March 2025.
• Ian Chan was removed as Chief Executive Officer for cause in March 2025.
• Robert Markelewicz, Chief Medical Officer, was furloughed effective September 30, 2025, with employment terminated effective November 30, 2025.
• Management believes ABP-102 has the potential to provide longer lasting or even curative results in a broader set of patients than currently addressed by HER2-directed therapies.
• Management believes the TetraBi antibody format of ABP-102 provides a potentially transformative approach to immuno-oncology.
• Management believes ABP-201 will require less frequent dosing, providing a significant advantage in the commercial setting for ophthalmology.
• Management believes the company's proprietary antibody platforms and approach overcome limitations in traditional antibody creation, but acknowledges the need for clinical trials and commercialization.

Industry Context

Abpro Holdings operates in the highly competitive biotechnology and biopharmaceutical industries, specifically targeting immuno-oncology and ophthalmology. The global HER2+ breast and gastric cancer market is projected to reach $12.1 billion by 2030, while the global ophthalmology market is expected to reach $84 billion by 2030, with the wet AMD market alone projected at $10.4 billion by 2024. The company aims to differentiate its novel antibody constructs, such as TetraBi antibodies, from existing therapies and competitors by offering improved efficacy, better safety profiles, and more convenient dosing regimens. The bispecific antibody field is relatively new, with limited FDA approvals, which may increase regulatory complexity.

Comparison to Industry Standards

• ABP-102 is positioned as an improvement over currently approved HER2-targeting agents like Herceptin (trastuzumab), Perjeta (pertuzumab), and Kadcyla (T-DM1) by relying on T-cell redirection to selectively eliminate tumor cells while sparing endogenous HER2-expressing cells.
• ABP-102's TetraBi antibody format with bivalent HER2 binding is designed to create a stronger connection to tumor cells compared to monovalent binding in other T-cell engaging bispecific antibodies.
• ABP-102's Fc region engineering aims to reduce unwanted side effects like cytokine release syndrome (CRS) compared to first-generation bispecific antibodies (BiTEs) and other T-cell targeted therapies.
• ABP-201, a dual VEGF and ANG-2 inhibitor, is compared to existing standard-of-care treatments for DME and Wet AMD, such as Eylea (aflibercept), Lucentis (ranibizumab), and Avastin (bevacizumab).
• ABP-201's high binding capacity and longer half-life in the eye are expected to require less frequent dosing compared to current agents like Eylea and Lucentis, which often require monthly or bi-monthly injections.
• Vabysmo (faricimab), a recently FDA-approved VEGF and ANG-2 co-targeting agent, provides strong support for ABP-201's dual-inhibition approach, with ABP-201 aiming for two binding sites for each target versus Vabysmo's single binding site per target.
• The company's TetraBi antibodies are presented as having several advantages over CAR T therapies, including simpler administration, no lengthy modification process for T cells, no need for chemotherapy to deplete immune cells, easier toxicity management, and potentially lower cost.

Management Changes

Corporate Governance

Legal Proceedings

• A lawsuit from a contract research organization (CRO) vendor resulted in a judgment of approximately $700,000 against the company as of January 24, 2024, for failure to make installment payments under a settlement agreement.
• Memorial Sloan Kettering Cancer Center (MSK) terminated an exclusive license agreement in September 2023 due to the company's failure to fulfill payment obligations, demanding approximately $1.2 million in principal and interest.
• The company is in breach of its license agreement with MedImmune/AstraZeneca for ABP-201, having missed target dates for IND application (July 2021) and Phase II commencement (December 2022), which gives MedImmune/AstraZeneca a termination right.
• A complaint was received on June 17, 2025, from a former director asserting that the company owes $748,000 for consulting fees, bonuses, and unpaid promissory note principal and interest.
• On November 10, 2025, the Suffolk Superior Court in Massachusetts issued a preliminary injunction prohibiting the transfer of the company's assets outside the ordinary course of business.
• A demand for payment of approximately $182,000 was received from Integral Molecular, Inc. on October 22, 2025, with negotiations ongoing.
• A demand for payment of $140,000 was received from Brookline Capital Markets on October 23, 2025, with negotiations ongoing.

Related Party Transactions

• Promissory note agreement with Abpro Bio International, Inc. (ABI), a significant investor, for up to $6 million, with $4.225 million converted into common shares at the Merger closing.
• Additional promissory note with ABI (2024 ABI Note) for up to $1 million, repaid at the Merger closing from PIPE Financing proceeds.
• Promissory notes issued to an executive and a director (Ian Chan) on December 29, 2023, for deferred bonuses, with $150,000 principal outstanding as of September 30, 2025.
• Promissory note agreement with an executive (Ian Chan) on April 18, 2024, for up to $2.158 million, with $1.997 million converted into 20,000 common shares at the Merger closing.
• Issuance of 28,333 Ian Chan Warrants to an executive on February 7, 2025, in satisfaction of a promissory note agreement.
• Consulting agreement with NEM LLC, whose sole member is Eugene Chan (former Chairman), for annual payment of $250,000, terminated during 2024.
• Payment of $574,000 to Atlantic Coastal Acquisition Management II LLC (the Sponsor) on December 24, 2024, in accordance with the Merger Agreement.
• Issuance of 16,667 RSUs to the Chief Executive Officer (Miles Suk) on July 25, 2025, under a consulting agreement.

Stakeholder Impact

• Shareholders face significant dilution risk from the potential sale of 9,775,017 shares under the SEPA, representing 360% of current outstanding shares.
• Shareholders are exposed to substantial financial risk due to the company's going concern warning, accumulated deficit, and ongoing losses.
• The risk of Nasdaq delisting could severely impact the liquidity and market price of the company's Common Stock and Public Warrants.
• Employees may face uncertainty due to the company's financial instability, as evidenced by personnel furloughs and reductions in R&D activities.
• Collaboration partners (Celltrion, Abpro Bio, NJCTTQ) may be impacted by the company's financial condition and potential breaches of agreements.
• Creditors are exposed to risk given the company's inability to pay certain obligations, leading to lawsuits and demands for payment.

Next Steps

• Initiate Phase 1/2 clinical trial for ABP-102 in the first half of 2026.
• Advance ABP-201 into Phase 1 clinical trials in the second half of 2026, contingent on funding.
• Initiate clinical trials for ABP-110 and ABP-150 in the first half of 2027.
• Continue fundraising efforts through equity and debt financings, collaboration agreements, and research grants.
• Address Nasdaq listing compliance requirements to avoid delisting.
• Finalize a settlement agreement with MSK regarding demanded payments.
• Engage in discussions with Mabwell regarding a $3.3 million claim for development milestones.
• Negotiate settlements for demands from Integral Molecular, Inc. ($182,000) and Brookline Capital Markets ($140,000).

Key Dates

Recommendation

Abpro Holdings is in a precarious financial position, marked by a 'going concern' warning, substantial accumulated deficit, and critically low cash reserves. The company faces imminent threats of Nasdaq delisting due to multiple non-compliance issues, which would severely impair liquidity and investor confidence. The recent 1-for-30 reverse stock split is a desperate measure that often fails to sustain long-term value. Furthermore, the potential for massive dilution from the $50 million SEPA, representing 360% of current outstanding shares, presents an unacceptable risk for existing shareholders. Ongoing legal disputes and a breach of a key license agreement add to the operational and financial instability. While the preclinical pipeline has theoretical potential, it is far from commercialization and requires significant, uncertain future funding. Given the severe financial distress, high operational risks, and the likelihood of further dilution and value erosion, a 'strong sell' recommendation is warranted.

Keywords

Biotechnology, Antibody Therapeutics, Immuno-oncology, Ophthalmology, HER2+ Cancer, Wet AMD, Diabetic Macular Edema, ABP-102, ABP-201, DiversImmune, MultiMab, SEC Filing, S-1/A, Nasdaq, Going Concern, Dilution, Clinical Trials, Preclinical Development, Standby Equity Purchase Agreement, YA II PN, Ltd., Reverse Stock Split, Corporate Governance, Financial Reporting