Bolt Biotherapeutics, Inc.

Bolt Biotherapeutics, Inc. is a clinical-stage biopharmaceutical company focused on developing novel immunotherapies for cancer, leveraging its proprietary Boltbody™ Immune-Stimulating Antibody Conjugate (ISAC) platform technology and deep expertise in myeloid biology ¹. The company's core business model revolves around the discovery, development, and potential commercialization of these ISACs, which combine tumor-targeting antibodies with immune-stimulating linker-payloads to activate the patient's immune system against tumor cells ¹. Revenue is primarily generated through collaboration agreements, which include upfront payments, research funding, and reimbursement for research and development services, recognized over time based on progress towards performance obligations ². The company has not yet generated any product revenue ³.

The company's pipeline candidates are built on its myeloid biology expertise and the Boltbody™ ISAC platform ¹. The primary focus is on BDC-4182, a next-generation Boltbody™ ISAC targeting claudin 18.2, a clinically validated oncology target ¹. BDC-4182 is currently in a first-in-human Phase 1 dose escalation trial for gastric/gastroesophageal junction cancer ¹. Preclinical studies for BDC-4182 have shown potent anti-tumor activity, safety, tolerability, and enhanced anti-tumor activity compared to cytotoxic antibody-drug conjugates (ADCs) ¹. The company's other pipeline programs, including a CEA ISAC, a PD-L1 ISAC, and BDC-3042 (a dectin-2 agonist antibody), are currently on hold ¹. The CEA ISAC targets carcinoembryonic antigen cell adhesion molecule 5, expressed in various solid tumors, and has shown promising preclinical activity including complete tumor regression and immunological memory ¹. The PD-L1 ISAC uses a novel human anti-PD-L1 antibody conjugated to a next-generation TLR7/8 agonist payload, demonstrating direct activation of PD-L1-positive antigen-presenting cells and complete tumor regression in preclinical models ¹. BDC-3042, a first-in-class dectin-2 agonist antibody, aims to repolarize tumor-associated macrophages (TAMs) from tumor-supportive to tumor-destructive, and has shown a favorable safety profile, dose-dependent biologic activity, and monotherapy anti-tumor activity in a Phase 1 dose-escalation study, but its development is currently paused as the company seeks partnering or additional funding ¹.

For the fiscal year ended December 31, 2025, Bolt Biotherapeutics reported collaboration revenue of $7.695 million ⁴. Total operating expenses were $43.808 million ⁴, leading to a loss from operations of $36.113 million ⁴. Net loss for the year was $33.376 million ⁵, resulting in a basic and diluted net loss per share of $(17.85) ⁶. The company's cash and cash equivalents stood at $11.703 million ⁷, with short-term investments of $15.802 million ⁸ and long-term investments of $4.337 million ⁹. Total cash, cash equivalents, and marketable securities were $31.8 million as of December 31, 2025 ¹⁰. Total liabilities were $30.243 million ¹¹, and total stockholders' equity was $26.505 million ¹². Net cash used in operating activities was $39.850 million ¹³.

Comparing 2025 to 2024, collaboration revenue remained relatively flat, increasing by $5 thousand from $7.690 million in 2024 to $7.695 million in 2025 ⁴. Total operating expenses decreased significantly by $36.930 million, from $80.738 million in 2024 to $43.808 million in 2025 ⁴. This reduction was primarily driven by a $28.936 million decrease in research and development expenses, from $57.469 million in 2024 to $28.533 million in 2025 ⁴. General and administrative expenses also decreased by $4.662 million, from $18.457 million in 2024 to $13.795 million in 2025 ⁴. Restructuring charges decreased by $1.863 million, from $3.343 million in 2024 to $1.480 million in 2025 ⁴. The company reported no impairment charges in 2025, compared to $1.469 million in 2024 ⁴. Net loss improved from $(63.118) million in 2024 to $(33.376) million in 2025 ⁵. Interest income, net, decreased by $2.759 million, from $5.255 million in 2024 to $2.496 million in 2025 ⁴. Other income, net, decreased by $4.434 million, from $4.675 million in 2024 to $0.241 million in 2025 ⁴.

Significant operational developments during the period include a strategic pipeline prioritization and restructuring plan announced in May 2024, which reduced the workforce by approximately 50 employees (50% of the workforce) and discontinued the development of trastuzumab imbotolimod to focus on BDC-3042 and BDC-4182 ¹. This resulted in restructuring charges of $3.6 million in 2024 ¹. In October 2024, the company established a wholly-owned subsidiary in Australia to expand its global footprint and enhance research and development capabilities ¹. A further restructuring plan was announced in October 2025, reducing the workforce by approximately 20 employees (50% of the remaining workforce) to preserve cash, incurring a restructuring charge of $1.5 million ¹. In March 2024, the Innovent collaboration was restructured, granting Bolt exclusive worldwide rights to BDC-4182 and related ISAC programs, with Innovent eligible for milestone payments up to $112.7 million and low single-digit royalties on global net sales ¹.

The company's current operating plans indicate that its existing cash, cash equivalents, and marketable securities of $31.8 million as of December 31, 2025, may be sufficient to fund operations into early 2027 ¹⁰. However, management has concluded that there is substantial doubt about the company's ability to continue as a going concern within one year after the filing of this Annual Report ¹⁰. This assessment is based on the company's history of net losses and negative cash flows from operations, with an accumulated deficit of $460.8 million as of December 31, 2025 ¹⁴.

The primary growth area for Bolt Biotherapeutics is the clinical development of BDC-4182, its claudin 18.2 ISAC ¹. This program is currently in a first-in-human Phase 1 dose escalation trial for gastric/gastroesophageal junction cancer, with the goals of selecting a recommended Phase 2 dose and demonstrating safety and anti-tumor activity ¹. The company believes that successful demonstration of anti-tumor efficacy and acceptable tolerability with BDC-4182 will validate its Boltbody ISAC platform, potentially positioning Bolt as a leader in developing first-in-class ISACs for various antigens ¹. The company also has three pipeline programs on hold—a CEA ISAC, a PD-L1 ISAC, and BDC-3042—that can be quickly restarted, with BDC-3042 development currently paused as the company seeks partnering or additional funding ¹.

The operational outlook includes continued efforts to manage expenses, as evidenced by the restructuring plans in May 2024 and October 2025, which reduced the workforce by approximately 50% and 50% respectively, to reduce overall operating expenses and preserve cash ¹. The company expects to continue incurring significant research and development expenses for the foreseeable future as it advances its product candidates, particularly those in later stages of development which typically have higher costs ¹. General and administrative expenses are also expected to continue as the company supports research and development and operates as a public company, including costs for audit, legal, regulatory, tax, director and officer insurance, and investor relations ¹⁵.

Planned capital allocation will prioritize funding the completion of key milestones for clinical programs and ongoing operations, including research and development activities and employee salaries ¹⁶. Significant costs are anticipated for clinical trials and manufacturing of product candidates ¹⁶. The company expects its long-term funding requirements to grow with the advancement of its programs, influenced by portfolio prioritization decisions and the success of collaborations ¹⁶. Future capital needs are expected to be financed through equity or debt financings, or other capital sources such as collaborations, licenses, or the sale of future royalties ¹⁶.

Management has explicitly flagged structural headwinds and execution risks, including the inherent uncertainty and high risk of biopharmaceutical product development, the unproven nature of the Boltbody ISAC approach, and the potential for product candidates to fail in clinical development or never achieve commercial value ¹. The company has a limited operating history and has incurred significant losses since inception, anticipating continued losses for the foreseeable future and potentially never achieving profitability ¹. The need for substantial additional funding is a critical risk, as an inability to raise capital on favorable terms could force delays, reductions, or termination of product development and commercialization efforts ¹.

Geographic, regulatory, and macro factors identified as constraints include the highly regulated nature of the biotechnology and pharmaceutical industry, with extensive government regulation in the U.S. and other countries governing all stages of product development and commercialization ¹. Enacted and future legislation, such as the One Big Beautiful Bill Act (OBBBA) and other healthcare reform measures, are expected to increase the difficulty and cost of obtaining marketing approval and commercializing product candidates, potentially affecting pricing and reimbursement ¹. International trade policies, including tariffs, sanctions, and trade barriers, may adversely affect the business, particularly given reliance on third-party suppliers in several countries outside the United States for antibody production, linker-payload manufacturing, and ISAC manufacturing ¹. Macroeconomic uncertainties, including increased inflation, interest rates, financial market fluctuations, and geopolitical conflicts, are also expected to continue impacting the business, potentially disrupting supply chains, manufacturing, and clinical trial activities ¹.

The company faces material risks including substantial doubt about its ability to continue as a going concern, with cash and cash equivalents and marketable securities of $31.8 million as of December 31, 2025, believed to be insufficient to fund operations for at least one year from the financial statement issuance date ¹⁰. The unproven nature of its Boltbody ISAC approach and the high risk of failure in clinical trials pose significant operational risks, as demonstrated by the discontinuation of trastuzumab imbotolimod due to insufficient efficacy ¹. Dependence on third-party CDMOs for manufacturing introduces supply chain risks, including potential disruptions from macroeconomic uncertainties, pandemics, or geopolitical conflicts, which could delay development or commercialization ¹. Regulatory risks are significant, with enacted and future legislation, such as the One Big Beautiful Bill Act (OBBBA), potentially increasing the cost and difficulty of obtaining marketing approval and affecting product pricing and reimbursement ¹. Intellectual property protection is crucial, and challenges to patents, inability to obtain or maintain licenses, or misappropriation of trade secrets could severely harm the company's competitive position ¹. The company also faces intense competition from larger, more established pharmaceutical and biotechnology companies with greater financial resources and experience ¹.

Management's message to shareholders emphasizes a mission to harness the immune system to eradicate cancer, acknowledging that this often involves taking new and unproven approaches ¹. The strategic priorities are centered on developing BDC-4182, a first-in-class claudin 18.2-targeting ISAC, leveraging the proprietary Boltbody ISAC approach and myeloid expertise to develop a pipeline of immune-activating therapies, and selectively entering into collaborations to expand and enhance the platform and increase the impact of product candidates ¹. Management explicitly states that under the current plan, the company's cash and cash equivalents and marketable securities of $31.8 million as of December 31, 2025, may be sufficient to fund operations into early 2027 ¹⁰, but also concludes that there is substantial doubt about the company's ability to continue as a going concern within one year after the filing of this Annual Report ¹⁰. The company will need to raise additional capital through partnering, selling equity, or other means ¹⁰.