ALPX S-1/A amended IPO prospectus section summaries

Alopexx, Inc. — Cover

Alopexx, Inc. filed Amendment No. 20 to its Form S-1 on October 26, 2026, for a proposed firm-commitment initial public offering of 3,000,000 common shares at an estimated price of $10–$12 per share. The estimated gross proceeds are $30–$36 million, before underwriting compensation and expenses; the final price and proceeds remain blank in the preliminary prospectus. Underwriters would receive a 7% discount and a separate non-accountable expense allowance equal to 1% of the IPO price. They also have a 45-day option to buy up to 450,000 additional shares—15% of the base offering—to cover over-allotments.

Alopexx has applied to list its shares on NYSE American under the symbol ALPX, but approval is not assured; the offering will not proceed if the listing is not approved. No public market for the shares existed before the offering, so their market and liquidity remain uncertain. The preliminary prospectus also cautions that the terms and information may change and that the shares cannot be sold until the registration statement becomes effective.

After the offering, CEO Daniel Vlock is expected to control 55.8% of voting power, assuming conversion of outstanding convertible notes into 195,425 shares and including shares underlying vested options exercisable within 60 days; this estimate assumes the underwriters do not exercise their over-allotment option. Alopexx will therefore qualify as an NYSE American “controlled company,” although it says it does not intend to rely on the exchange’s corporate-governance exemptions.

Alopexx identifies as a non-accelerated filer, smaller reporting company, and emerging growth company, and has elected reduced public-company reporting requirements. The cover provides no operating or balance-sheet figures; it does not quantify financial performance, liquidity, or business-specific risks.

Alopexx — Prospectus Summary

Business and clinical programs

Alopexx is a clinical-stage biotechnology company developing immune therapies targeting PNAG, which it says is expressed by more than 75 bacterial, fungal, and parasitic pathogens, including antimicrobial-resistant microbes. It has no approved products or commercial revenue, a limited operating history, and depends heavily on two early-stage candidates:

• AV0328, a synthetic vaccine, completed a Phase 1 first-in-human trial. The company reports it was well tolerated, with no serious adverse events, and elicited antibodies that killed tested PNAG-expressing pathogens in laboratory studies across more than 10 microbial species. A proposed initial use is as a complement to pneumococcal vaccines: Alopexx says existing vaccines cover at most 23 of approximately 100 Streptococcus pneumoniae serotypes, leaving more than 80 potentially unaddressed. The company is pursuing an accelerated-approval approach based on human safety data and a validated opsonic-killing assay, but regulators may require field-efficacy trials or other evidence; approval and the proposed pathway are not assured.
• F598, a fully human monoclonal antibody, completed Phase 1 and pilot Phase 2 trials. Alopexx reports good tolerability, no serious adverse events, and serum antibody levels sustained for 2–3 months after one infusion. It is proposed for prevention or mitigation of hospital-associated infections in ICU patients, as an adjunct to—not a replacement for—antibiotics and antifungals. A 1,600-patient Phase 2 ICU study is planned with Assistance Publique–Hôpitaux de Paris (AP-HP); the collaboration is described as agreed.

The company estimates annual global revenue above $2 billion for AV0328’s pneumococcal indication. For F598, it cites approximately 5 million annual U.S. ICU admissions and estimates peak U.S. sales of $3.0 billion annually at 60% market penetration. These are market estimates, not current revenue or demonstrated demand; realization depends on clinical success, approval, pricing, and adoption. Alopexx argues that long-acting immune therapies could complement current care while avoiding the resistance-selection concern it associates with sparing use of newer antibiotics.

Alopexx’s platform rationale is that native PNAG’s high acetylation produces weak natural immunity, while its chemically modified PNAG approach targets the backbone to elicit more protective antibody responses. Beyond infectious diseases, the company reports preclinical animal findings in Alzheimer’s disease, traumatic brain injury, and type 1 diabetes; these are not established clinical benefits. It anticipates development of related antibody AB0411 and vaccine AV0407 for neuroinflammatory indications in Q1 2027, using distinct formulations rather than entirely new chemical entities. Other potential populations include people with B-cell deficiencies or immunosuppression. Development timelines and clinical utility remain uncertain.

Financial condition and offering

The company reports no revenue. For H1 2026, R&D expense was $259,925 (from $109,432 in H1 2025) and G&A was $604,164 (from $1.278 million). Total operating expenses and operating loss were each $864,089 (from $1.387 million). Other expense, net, was $146,536 (from $142,295), and net loss was $1.011 million (from $1.529 million). Basic and diluted loss per share was $0.20 (from $0.31); weighted-average shares were 5,065,284 (from 4,908,641). Pro forma as-adjusted H1 2026 loss per share is $0.12, based on 8,260,709 weighted-average shares, reflecting note conversion and the offering.

For FY 2025, R&D expense was $198,406, G&A $2.119 million, total operating expenses and operating loss $2.317 million, other expense $291,258, and net loss $2.608 million. For FY 2024, the corresponding figures were $223,998, $2.591 million, $2.815 million, $245,811, and $3.061 million. Annual loss per share was $0.53 in 2025 versus $0.63 in 2024. Operating cash flow and capital expenditures are not provided in the summaries.

At June 30, 2026, actual total assets were $981,003, including cash of $97,586 and deferred offering costs of $883,417; stockholders’ deficit was $6.422 million. Liabilities included $1.250 million of convertible notes payable, $1.450 million of notes payable, and $971,910 of accrued interest. Pro forma conversion of $1.612 million of convertible notes, including accrued interest, reduced the deficit to $4.810 million and accrued interest to $609,653. Pro forma as adjusted for the IPO, cash and total assets are each $30.245 million, and stockholders’ equity is $24.454 million; notes payable remain $1.450 million and accrued interest $609,653. Goodwill and intangible assets other than goodwill are not separately reported.

The proposed IPO is 3.0 million shares at an assumed $11.00 per share, with estimated net proceeds of $30.1 million, or $34.7 million if the 450,000-share over-allotment is fully exercised. Proceeds are intended to advance the candidates, complete AV0328 proof-of-concept trials, scale up F598 manufacturing, and fund general corporate purposes, working capital, operating expenses, and capital expenditures. Shares outstanding were 5,299,557 at August 31, 2026; expected post-offering shares are 8,299,557, or 8,749,557 with full over-allotment. The count reflects conversion of $1.612 million of convertible notes into 195,425 shares at $8.25 per share. It excludes 1,419,388 options at a $4.04 exercise price and 1,803,562 shares reserved under the 2023 Equity Incentive Plan. Alopexx expects to be a controlled company after the offering.

Execution, risks, and outlook

Alopexx plans to pursue further indications and collaborations, strengthen intellectual property, and establish scalable manufacturing. Its portfolio includes four patent families with stated coverage through 2040–2042, four exclusively licensed issued U.S. and PCT patents from Brigham and Women’s Hospital, a trade-secret agreement covering PNAG oligosaccharide synthesis, and a proprietary F598 master cell bank.

Recurring losses and planned spending raise substantial doubt about the company’s ability to continue as a going concern without sufficient financing. Alopexx expects substantial net losses for the foreseeable future and may need additional capital even after the IPO; a shortfall could delay, reduce, or terminate programs. Other material risks include uncertain clinical timelines and costs, regulatory requirements, reliance on third-party manufacturers and suppliers including Lonza and Glycosyn, competition from better-resourced companies, and maintaining adequate patent protection. Epidemics could disrupt trials and manufacturing. The prospectus also refers to current IP litigation without details in the provided summary. Alopexx is an emerging growth company and elected reduced public-company disclosure requirements, including the extended transition period for certain accounting standards, which may limit comparability.

Business and financial position

ALPX is a clinical-stage vaccine company, incorporated in June 2021, with two early-stage programs: vaccine candidate AV0328 and monoclonal antibody F598. Both have completed Phase 1 studies, but neither is approved, and the company has generated no product-sales revenue. ALPX has not yet demonstrated that it can complete pivotal trials, obtain approval, manufacture at commercial scale, or successfully commercialize a product.

The company reported a $2.608394 million net loss for FY2025, versus $3.060624 million for FY2024, and an accumulated deficit of $17.723578 million as of June 30, 2026. Cash and cash equivalents were approximately $98,000 as of June 30, 2026. The FY2025 auditor’s report included a going-concern explanatory paragraph, citing working-capital deficiency, recurring losses, negative operating cash flows, and the need for additional funding. ALPX expects substantial losses for several years and may never become profitable.

ALPX estimates net offering proceeds of approximately $30.1 million, assuming an $11.00-per-share offering price and after estimated underwriting discounts, commissions, and expenses. It believes the proceeds and existing cash will fund current plans for at least 12 months from the prospectus date, but expects to need additional capital before advancing a vaccine into a pivotal trial. No further funding is committed. Financing could be unavailable or costly: equity or convertible debt may dilute shareholders, debt may impose fixed payments and covenants, and partnerships or licenses may require surrendering valuable rights or revenue. Insufficient funding could delay, reduce, or end development.

Development, regulatory, and manufacturing risks

Approval is uncertain and may require more extensive studies than ALPX currently anticipates. The company hopes AV0328 may be evaluated using surrogate immune endpoints, but regulators could require field-efficacy, vaccine-interference, comparative, or other additional trials. AV0328’s non-serotype-specific approach is novel and has no FDA-approved or commercial precedent. Results may be inconclusive, fail to establish an acceptable benefit-risk profile, or be interpreted differently by regulators; safety issues, enrollment challenges, changing standards of care, site or manufacturing inspections, and CRO performance could delay or prevent approval. Trials may be costly and lengthy, and delays can reduce effective patent-protected commercial time or allow competitors to reach the market first. Interim or topline results may change as data are verified. ALPX withdrew earlier Fast Track applications for AV0328 and F598 and may reapply, but expedited designations are not assured. It is also considering an F598 Phase 2 trial outside the U.S.; regulators may not accept foreign trial data.

The company has no internal manufacturing capability and relies on third parties for development and supply. The summaries identify Bharat Biopharm as the vaccine clinical-supply CMO, Glycosyn as the source of a key vaccine oligosaccharide component, and Lonza for process development and clinical manufacturing/supply for the antibody and F598 drug product. Reliance on limited suppliers, including a sole-source component, creates exposure to shortages, quality or cGMP failures, capacity constraints, contract termination, unfavorable pricing, and disruptions. Replacing a supplier or transferring and validating processes could be expensive and time-consuming; ALPX does not control third-party manufacturing. Lonza agreements denominated in Swiss francs also expose costs to currency movements. Disasters, geopolitical events, pandemics, labor or utility interruptions, and failures at company or partner facilities could disrupt trials and supply; insurance may not cover resulting losses.

ALPX also depends on external investigators, universities, trial sites, CROs, and strategic partners, while retaining responsibility for regulatory compliance. Poor data, GCP failures, recruitment problems, missed deadlines, or partner termination may require repeat work or delay development. The company lacks sales, marketing, and distribution infrastructure and may need substantial investment or commercial partners whose availability and performance are uncertain.

Commercial, legal, and intellectual-property exposure

Even an approved product may have limited uptake. Coverage and reimbursement vary among payors and countries; inadequate reimbursement, high patient costs, government price controls, cost-effectiveness requirements, or payment rules could constrain demand and returns. CDC/ACIP recommendations can materially affect vaccine use and may change. A potential catch-up or booster market could shrink after initial uptake. Pfizer, Merck, GlaxoSmithKline, and Sanofi collectively control approximately 75% of the global vaccine market and have greater resources, established distribution, and competing programs, creating substantial risk that AV0328 could lose market share or fail to recover development costs.

ALPX relies on patents, trade secrets, and confidentiality arrangements, including licensed PNAG-platform intellectual property from Brigham and Women’s Hospital. Patent applications may not issue or may be challenged, narrowed, invalidated, or lapse; development delays may shorten practical exclusivity. The license carries development, funding, milestone, royalty, diligence, and patent obligations, and termination could deprive ALPX of important rights. Third-party infringement claims or disputes over confidential information and ownership could require costly licenses, redesign, damages, or halt development. The company has not selected or filed trademarks for its vaccine. Separately, Xenothera’s French claims seeking an AV0328 license or €120 million in damages were rejected in full on September 24, 2025; Xenothera withdrew its claims and appeal and paid ALPX €125,000, and ALPX withdrew its U.S. case.

Healthcare, privacy, product-promotion, and clinical-trial compliance requirements may impose significant costs. Alleged misconduct or violations can result in investigations, fines, damages, exclusion from government programs, restrictions, or reputational harm. Cyberattacks and evolving privacy and cross-border data rules could disrupt trials, expose sensitive data, or trigger penalties, including under GDPR. Product-liability claims could lead to litigation, recalls, restricted use, or substantial awards; insurance may be inadequate or unavailable. ALPX also reports no insurance for liabilities arising from hazardous or medical materials.

Offering, governance, and public-company risks

Before the offering, no public market existed, and a liquid market may not develop. Shares may be volatile, and later sales could pressure the price. At the assumed $11.00 IPO price, stated immediate dilution is $8.05 per share in pro forma as-adjusted net tangible book value; options and a warrant priced below the IPO price may add dilution. ALPX does not expect to pay dividends. Executives, directors, and 5% holders owned approximately 97.82% of voting stock as of June 30, 2026, and are expected to own approximately 72.8% after the offering. CEO Daniel Vlock is expected to control approximately 55.8% of voting power under the stated assumptions, making ALPX a NYSE American controlled company and allowing possible exemptions from certain independent-board and committee requirements.

The company expects 8,299,557 shares outstanding after the offering, or 8,749,557 if the over-allotment is fully exercised. 3,000,000 offering shares, plus any over-allotment shares, are expected to be immediately tradable; most existing holders are subject to 180- or 365-day lock-ups, which may be waived. Charter and bylaw provisions, including a classified board and restrictions on shareholder actions, and Delaware takeover rules may deter or delay transactions.

ALPX previously identified a material weakness in financial reporting controls related to staffing, segregation of duties, journal entries, and reconciliations. It reports remediation efforts, including hiring a CFO and accounting advisor, but cannot assure controls will remain effective; it is exempt from auditor attestation while an emerging growth company. Public-company compliance will add costs and management demands, while delisting or lack of analyst coverage could reduce liquidity and investor demand.

Forward-Looking Statements and Key Risks

The prospectus describes a development-stage vaccine and antibody business and reports no historical financial results or operating metrics in this section. Its outlook depends on assumptions about vaccine benefits, breadth of protection and immunogenicity; whether preclinical findings will predict clinical outcomes; and whether regulators may accept surrogate immune endpoints instead of requiring clinical field-efficacy studies.

Advancing vaccine and antibody candidates will require completing preclinical and clinical programs, developing scalable manufacturing, protecting intellectual property, and—if products are approved—commercializing them. Key uncertainties include clinical or regulatory failure and delay, competition, manufacturing scale-up, pricing and reimbursement, and government regulation. The company also faces uncertainty about market size, future revenue and expenses, and capital requirements, including the possibility of needing additional financing through this or future offerings. Other identified risks include intellectual-property disputes, attracting and retaining key personnel, stock-price volatility, and uncertainty over how long the company will qualify as an emerging growth company.

Forward-looking statements reflect expectations and information available as of the prospectus date, may rely on limited or incomplete information, and actual results may differ materially. The company generally disclaims an obligation to update these statements except as required by law. They also do not account for the potential effects of future acquisitions, mergers, dispositions, joint ventures, or investments.

Use of Proceeds

At an assumed IPO price of $11.00 per share, ALPX expects net proceeds of approximately $30.1 million, or $34.7 million if the underwriters’ option is exercised in full, after estimated underwriting discounts, commissions, and offering expenses. Net proceeds would change by approximately $2.8 million for each $1.00 change in the offering price and by approximately $1.0 million for each 100,000-share change in shares offered, assuming other variables remain constant.

ALPX plans to allocate approximately $19.0 million to advance its pipeline:

• $6.0 million to initiate a proof-of-concept trial of vaccine AV0328, including manufacturing and correlative laboratory studies.
• $9.0 million to initiate a proof-of-concept trial of its monoclonal antibody in ICU patients.
• $4.0 million to initiate development of monoclonal antibody AB0411 and vaccine AV0407 for Alzheimer’s disease and neuroinflammation, anticipated to begin in Q1 2027.

The remaining proceeds, together with existing cash, are intended for general corporate purposes, including working capital, operating expenses, capital expenditures, and potential expansion of the pipeline. The offering is also intended to strengthen capitalization and financial flexibility, establish a public market for the common stock, facilitate future equity-market access, and increase the company’s visibility.

Management estimates that offering proceeds plus current cash and cash equivalents will cover operating expenses and capital expenditures for at least the next 12 months. This funding is not sufficient to finance a pivotal clinical trial for any candidate, and ALPX expects to need additional capital to complete development and commercialization of the vaccine. Potential sources include equity or debt offerings, government or other third-party funding, collaborations, strategic alliances, and licensing arrangements. The runway estimate depends on assumptions that may prove incorrect, and actual spending could exceed expectations.

Management retains broad discretion over use of the proceeds, which may change depending on research results, clinical and preclinical progress, regulatory timing, and collaboration funding. ALPX may also use proceeds for acquisitions or strategic investments, although it has no current agreements or commitments to do so. Until used, proceeds are expected to be invested in short- or intermediate-term interest-bearing obligations, investment-grade instruments, certificates of deposit, or direct or guaranteed U.S. government obligations.

The company has never declared or paid cash dividends and does not expect to pay them in the foreseeable future. It expects to retain available funds and any future earnings to finance business development and expansion. Any future dividend would be at the board’s discretion, taking into account the company’s financial condition and results, contractual restrictions, capital needs, business prospects, and other relevant factors. Future agreements may also restrict dividend payments.

Capitalization at June 30, 2026

The pro forma conversion assumes the $1.25 million principal of convertible notes and $362,258 of accrued interest convert at $8.25 per share into 195,425 common shares. This eliminates the convertible notes and improves the stockholders’ deficit; notes payable remain $1.45 million.

The as-adjusted case assumes an IPO of 3,000,000 shares at $11.00 per share, or $33.0 million in gross proceeds. After underwriting discounts, commissions, and estimated offering expenses, cash increases to $30.245086 million and stockholders’ equity becomes positive. The company’s accumulated deficit was $17.723578 million.

The adjusted share count excludes exercise of outstanding options, the underwriters’ 450,000-share option, and representative warrants. In addition to the stated post-offering shares, 1,419,388 shares are issuable under outstanding options and 1,803,562 shares are reserved for future issuance under the 2023 Equity Incentive Plan. The assumed IPO therefore substantially strengthens capitalization and liquidity, although the $1.45 million of notes payable remains outstanding.

Net Tangible Book Value and IPO Dilution

As of June 30, 2026, historical net tangible book value was a deficit of $7.3 million, or $1.43 per share. After assuming the automatic conversion of all outstanding convertible notes into 195,425 common shares and adoption of the amended and restated certificate of incorporation, pro forma net tangible book value was a deficit of $5.7 million, or $1.07 per share.

The dilution analysis assumes an IPO of 3,000,000 shares at $11.00 per share, with underwriting discounts, commissions and estimated offering expenses deducted from proceeds. On that basis, pro forma as-adjusted net tangible book value as of June 30, 2026 would be $24.5 million, or $2.95 per share. This represents a $4.02 per-share increase for existing stockholders from the pre-offering pro forma amount. New investors would face $8.05 per-share dilution relative to the assumed IPO price.

Shares and Consideration

After the assumed offering, pro forma shares outstanding would total 8,299,557:

• Existing stockholders: 5,299,557 shares (64%)
• New investors: 3,000,000 shares (36%)

Before underwriting discounts, commissions and estimated offering expenses, the stated consideration is $7,190,336 from existing stockholders (18% of aggregate consideration; $1.36 average per share) and $33.0 million from new investors (82%; $11.00 per share). Aggregate consideration is $40,190,336, or $4.84 average per share.

Offering Sensitivities and Underwriters’ Option

Assuming the share count is unchanged, a $1.00 increase or decrease in the assumed IPO price would change adjusted net tangible book value by $0.33 per share and investor dilution by $0.67 per share, in the same direction. Assuming the IPO price is unchanged, each 100,000-share increase or decrease in shares offered would change adjusted net tangible book value by $0.00 per share and change dilution inversely by $0.09 per share.

If the underwriters’ option is exercised in full, adjusted net tangible book value would be approximately $3.32 per share and dilution to new investors $7.68 per share. Existing stockholders’ ownership would decline to 61%, while offering investors’ ownership would rise to 39%.

The assumed offering substantially improves the company’s negative pre-offering tangible book value, but the assumed $11.00 IPO price remains well above adjusted tangible book value, leaving significant immediate dilution for new investors. Actual dilution will depend on final pricing and offering terms.

Business and development

Alopexx is a clinical-stage biotechnology company developing two PNAG-directed anti-infective candidates: monoclonal antibody F598 and synthetic vaccine AV0328. It has no commercial revenue or selling expenses, and its programs depend on continued external financing. Research and development costs are expensed as incurred and are not tracked or allocated by product candidate.

F598 completed Phase 1 and a pilot Phase 2 trial. The company reports good tolerability, no serious adverse events, and serum levels maintained for two to three months after one infusion. Alopexx plans to study F598 in intensive-care settings as potential immediate, broad-spectrum protection alongside—not instead of—antibiotics. Clinical benefit in ICU patients remains unproven.

AV0328 completed a first-in-human Phase 1 trial, with reported tolerability and minor, transient injection-site reactions. Laboratory testing showed antibody-induced opsonic killing across more than 10 PNAG-expressing microbial species. Alopexx proposes that the vaccine could complement pneumococcal vaccines, which cover at most 23 of roughly 100 known S. pneumoniae serotypes. Management says FDA feedback supported pursuing an accelerated-approval pathway using safety data and a validated surrogate assay, but approval and clinical efficacy are uncertain. The company also cites animal-study effects across 14 pathogens and 20 infection models; translation to humans is undetermined.

The technology originated at Brigham and Women’s Hospital and Harvard Medical School. Alopexx holds an exclusive worldwide, royalty-bearing BWH license. License terms include annual pre-commercial fees, low-single-digit royalties on net sales, and milestone obligations of up to $2.325 million for AV0328 and $1.850 million for F598 ($4.175 million total); sublicense income also triggers a low-double-digit percentage payment to BWH. The portfolio has four patent families, with coverage through 2040, supplemented by trade secrets and a proprietary F598 master cell bank. Bharat remains committed to its AV0328 license for low- and low-middle-income countries, including funding vaccine manufacture and supply for Alopexx’s clinical studies. A contemplated $1.5 million BCI share purchase was terminated in full on August 7, 2026.

Results and liquidity

For the six months ended June 30, 2026, operating expenses were $864,089, down from $1.387 million in the first half of 2025, and net loss was $1.011 million versus $1.529 million; loss per share was $0.20 versus $0.31. Weighted-average shares were 5,065,284 versus 4,908,641. R&D expense rose to $259,925 from $109,432, primarily because storage and shipping costs increased by about $150,000. G&A fell to $604,164 from $1.278 million, mainly reflecting lower stock-based compensation. Net interest expense increased to $146,536 from $142,295 as average outstanding debt rose.

Cash was approximately $98,000 at June 30, 2026, versus $142,000 at June 30, 2025. Operating cash use was approximately $531,000 in H1 2026, compared with $627,000 in H1 2025. Financing provided $600,000 in H1 2026 from related-party common-stock issuance, versus $500,000 in H1 2025 from related-party notes and stock issuance.

For FY2025, operating expenses were $2.317 million versus $2.815 million in FY2024; net loss was $2.608 million versus $3.061 million, and loss per share was $0.53 versus $0.63. Weighted-average shares were 4,947,002 versus 4,874,134. FY2025 R&D was $198,406 versus $223,998, while G&A declined to $2.119 million from $2.591 million. Lower G&A and stock-based compensation were central to the reduced losses. Net interest expense rose to $291,258 from $245,811.

Year-end cash was approximately $28,000 at December 31, 2025, versus $269,000 a year earlier. FY2025 operating cash use was approximately $1.140 million, compared with $481,000 in FY2024; financing provided $900,000 versus $700,000. Capital expenditures and beginning/end shares outstanding are not provided in the summarized disclosure.

Management says uncertainty about obtaining future financing raises substantial doubt about the company’s ability to continue as a going concern. It expects existing cash and offering proceeds to support current plans for at least 12 months from the offering date, but expects further capital will be needed before pivotal trials. Financing shortfalls could delay, reduce, or end development; equity or convertible financing could dilute shareholders, while debt could impose covenants. Substantial additional R&D costs are expected as candidates advance. A December 2024 agreement had contemplated CEO Daniel Vlock-related share issuances; across the listed transactions, the company issued him 204,914 shares for $1.2 million, including 127,931 shares for $600,000 in 2025 and 76,983 shares for $600,000 in H1 2026.

Valuation, risks, and controls

The estimated IPO price was $10.00–$12.00 per share, compared with a September 2024 independent valuation of $3.76 per share on a minority, non-marketable basis or $4.69 on a minority, marketable basis. The $3.76 valuation included a $0.93 per-share marketability discount. Management cites changed market conditions, subsequent preclinical findings and offering-pricing feedback; the small-cap biotech index rose approximately 94% over the trailing 52 weeks and 27% year to date through June 30, 2026. Reported preclinical findings involving Alzheimer’s disease and traumatic brain injury broaden potential indications but are not clinical or commercial outcomes.

The company has no formal foreign-exchange hedging program; exposure is mainly tied to a UK-based contract and other limited foreign-currency contracts. Management considers a 10% exchange-rate move immaterial to results, as it does a hypothetical 10% interest-rate movement. Inflation-related cost effects were not considered material in the periods presented.

A previously identified material weakness involved limited accounting/reporting personnel and inadequate segregation of duties. A CFO and accounting advisor were hired and processes improved, but Section 404 controls had not yet been tested or documented. The company expects public-company compliance costs and may need more personnel. It intends to use emerging-growth-company accommodations, including reduced disclosures and exemption from auditor attestation under Section 404(b) while eligible; early adoption of certain accounting standards may limit comparability with other public companies.

Business and development strategy

Alopexx is a clinical-stage biotechnology company developing two therapeutics that target PNAG, a microbial surface polysaccharide reported across more than 75 microbial species, including antibiotic-resistant organisms. Its strategy is to pursue broader coverage than vaccines or antibodies directed at individual pathogens or serotypes. The company detected PNAG in more than 90% of nearly 250 microbial strains tested, but expression is not universal: Pseudomonas aeruginosa and Proteus mirabilis were among exceptions, and expression varies in some other organisms. The platform’s rationale is supported by animal studies across 14 pathogens and 20 infection models and by laboratory evidence, but neither establishes benefit in people.

Alopexx’s initial priorities are AV0328, a synthetic PNAG vaccine, for pneumococcal prevention and F598, a monoclonal antibody, for preventing or mitigating infections in intensive-care-unit (ICU) patients. Broader infection-prevention uses are also being explored. The company additionally proposes a neuroinflammation pipeline, including Alzheimer’s candidates AV0407 and AB0411; these opportunities remain speculative, with human efficacy unestablished.

Product evidence and planned trials

AV0328: Phase 1 is complete. In 16 healthy volunteers, the vaccine was reportedly well tolerated, with no serious adverse events; minor, transient injection-site reactions were reported. Sera from immunized subjects showed PNAG antibody responses and laboratory killing activity against tested PNAG-positive organisms. The company detected PNAG in all 36 pneumococcal serotypes evaluated and reports protective-threshold opsonic killing against tested serotypes. These are early immunologic and laboratory findings, not evidence of clinical protection.

Alopexx aims to complement existing pneumococcal vaccines, which target limited sets of serotypes, and potentially address serotypes not covered by them. The company cites serotype replacement as a limitation of serotype-specific approaches. It says FDA feedback has supported exploring accelerated approval using safety data and opsonic killing as a surrogate endpoint; this is a proposed pathway, not an FDA approval or assurance that the endpoint will be accepted. A proposed Phase 2 study would enroll about 100 healthy adults over age 50 to assess dose, schedule, and durability. Further pivotal and pediatric studies would depend on results.

The vaccine’s antigen is chemically synthesized, avoiding dependence on variable microbial sources. Glycosyn has developed a scalable process, and Alopexx estimates production cost below $0.50 per dose; commercial-scale cost and execution remain unproven.

F598: Phase 1 in 20 healthy adults was reportedly well tolerated, with no serious adverse events or relevant anti-drug immunogenicity. Its half-life was approximately 20–30 days, and functional activity against S. aureus was dose-dependent through Day 50, the last measured time point. A separate open-label Phase 2 study infused 25 people with latent or newly diagnosed active tuberculosis; no serious or unexpected adverse events were reported, but the two-week study could not assess bactericidal activity and did not meet its Phase 2 efficacy endpoint.

In a mouse pneumococcal challenge, F598 showed dose-dependent protection; the greatest reported effect was comparable to post-infection cefotaxime. The company proposes that a single infusion could provide immediate protection for two to three months, unlike vaccines that take time to induce immunity. Human efficacy for ICU prevention remains unproven.

A planned 1,600-patient Phase 2 ICU study across eight AP-HP hospitals would randomize institutions, with ICUs crossing over between F598 and placebo after six months; standard care would be provided in both arms. It is intended to assess infection-related morbidity and mortality. Initial institutional approval has been received; initiation is anticipated in Q1 2027, completion about 18 months later, and estimated clinical cost is approximately $4 million. A positive result would support, but not replace, a later company-sponsored confirmatory registration study.

Market opportunity, competition, and manufacturing

The filing cites an estimated $8.73 billion global pneumococcal-vaccine market in 2025, forecast to reach $13.02 billion by 2033. Pfizer, Merck, and GSK products generated about $7.45 billion in combined sales. Alopexx positions AV0328 as complementary to existing products and higher-valency candidates, not as a proven replacement.

Company commercial models are projections, not realized results. For AV0328, a modeled $60 price per dose (range $45–$90) and assumed peak shares of 60% of pediatric Prevnar vaccinations and 65% among adults over 65 support estimated peak global annual pneumococcal revenue above $2.0 billion. For F598, a model using approximately 5 million U.S. ICU admissions annually, $1,000 per treatment, and 60% penetration estimates peak U.S. annual sales of $3.0 billion. The models depend on clinical success, approval, pricing, adoption, and reimbursement.

Alopexx reports alignment with Lonza on F598 manufacturing, including a commercial-scale cell line. It also cites potential emergency abdominal-surgery and trauma use, where postoperative infection rates are reported at 4%–31% despite perioperative antibiotics; the proposed benefit of longer protection without extended antibiotic exposure needs clinical testing.

Licensing, intellectual property, and operations

A 2024 license with BCI grants rights to co-develop and commercialize AV0328 for pneumococcal prevention and two additional indications in India and other licensed lower-income territories. Alopexx received $666,666 upfront and may receive approximately $1.3 million in additional upfront payments, up to $3 million for preclinical work and milestones, and royalties in the single digits on public-market sales and low teens on private-market sales. Development and commercialization in those territories depend on the partner, subject to contractual termination and transition provisions.

Exclusive BWH licenses cover vaccine-related rights and F598 and variants. Combined annual license fees are $165,000; the agreements include regulatory milestones, potential approval and commercialization milestones, low-single-digit net-sales royalties, and a low-double-digit share of sublicense income. The company must meet payment and development obligations; BWH controls prosecution, maintenance, and enforcement of licensed patents. Alopexx’s owned patent applications, if issued, are expected to expire in 2040–2042; licensed patents have different expiration dates. Patent validity and protection are uncertain.

Alopexx had three officers and did not plan to employ full-time staff before completing its IPO, underscoring its lean operating structure and reliance on external collaborators.

Principal risks and material developments

Clinical translation, efficacy, regulatory acceptance of surrogate endpoints, manufacturing execution, reimbursement, and commercial uptake are substantial uncertainties. FDA approval as a biologic would require review of safety, purity, and potency; the agency may require additional studies, restrict labeling, or delay or deny approval. Expedited designations do not lower the evidence standard, and accelerated approval can require confirmatory trials. Ongoing cGMP, trial, promotional, privacy, and healthcare fraud-and-abuse requirements create compliance and cost risks. U.S. and international pricing and reimbursement policies may constrain access or pricing.

Xenothera’s claims related to AV0328 work were fully rejected by the Paris Judicial Court on September 24, 2025. Xenothera waived its claims and withdrew related proceedings and its appeal; it paid Alopexx €125,000, and the court had also ordered payment of €25,000. Alopexx withdrew its U.S. case as part of the resolution, removing that asserted litigation exposure.

Management, Board and Governance

Alopexx’s management and governance disclosures focus on leadership experience and planned post-offering oversight; they do not report financial results or operating metrics.

Leadership and scientific experience

• Daniel Vlock, co-founder, CEO and director since 2021, has pharmaceutical drug-development and academic experience. With scientific co-founder Gerald Pier, he helped develop the F598 human monoclonal antibody against S. aureus and the AV0328 vaccine.
• Thomas Thomas, CFO, has more than 35 years of financial experience. At Genentech, he served as treasurer from 2001 to 2006 and led its investment program and enterprise risk management, as well as a $2 billion global debt offering.
• Christine de los Reyes, Chief Business/Commercialization Officer, has more than 30 years in pharmaceuticals, including 12 years in Pfizer licensing and development, and further partnering and licensing experience through her consulting firm.
• Director nominee Gail Cassell brings infectious-disease and anti-infective drug-development experience from Eli Lilly, academia and public-health advisory roles. Director and strategic advisor William Chin has senior pharmaceutical, academic and drug-regulatory advocacy experience.
• Scientific advisor Gerald Pier’s laboratory developed the PNAG-conjugate vaccine now in Phase 1 trials and the F598 antibody Alopexx is developing. His research has also produced antibodies studied in Phase 1 and Phase 2 trials for other PNAG-expressing pathogens.

Board structure and control

After the registration statement becomes effective, Alopexx expects a five-member classified board with staggered three-year terms: William Chin; Richard Cohen and Gail Cassell; and Daniel Vlock and Ann MacDougall. The company identifies Cohen, Cassell, MacDougall and Chin as independent. NYSE American phase-in rules allow up to one year after listing to reach a board with at least 50% independent directors.

The classified structure may delay or prevent a change in management or control. Board vacancies may be filled by a majority of directors present or by a majority of founder-share holders.

Following the offering, Alopexx expects to qualify as a controlled company under NYSE American rules. It says it does not currently intend to use the related governance exemptions, but may do so later; using them would reduce governance protections for stockholders. If the company ceases to be controlled while remaining listed, it will have to meet applicable requirements within transition periods.

Committees and policies

Alopexx plans to establish audit, compensation, and nominating and corporate governance committees, with written charters effective before the offering closes.

• Audit committee: Richard Cohen will chair, with Ann MacDougall and Gail Cassell as members. Cohen is identified as an SEC-defined audit committee financial expert. The committee’s responsibilities include financial reporting integrity and review, legal and regulatory compliance, auditor appointment, independence and performance, pre-approval of audit and non-audit services, related-party transactions, and accounting or compliance issues.
• Compensation committee: Ann MacDougall will chair, with William Chin and Richard Cohen as members; the company expects all members to meet independence requirements. The committee will oversee executive and director compensation and incentive and equity plans, and may retain advisers subject to an independence review.
• Nominating and corporate governance committee: Ann MacDougall will chair, with Richard Cohen and Gail Cassell as members; all are identified as independent. The committee will identify director candidates, recommend committee composition and governance practices, and oversee board evaluations. The company has no formal minimum qualifications for directors.

Alopexx has adopted a code of business conduct and ethics for directors, officers and employees, and intends to post required disclosures of amendments or waivers on its website.

Compensation disclosures

After the offering, directors or management may receive consulting or management fees or other compensation. Alopexx reports no executive or director agreements providing benefits upon termination. The section gives no compensation amounts or details of specific related-party arrangements.

Executive and director compensation

For FY2025 and FY2024, CEO Daniel Vlock reported no salary, bonus, stock or option awards, other compensation, or total compensation. CFO Thomas T. Thomas received salary and total compensation of $366,667 in each year, with no bonus, equity awards, or other compensation. Chief Business and Marketing Officer Christine de los Reyes reported no compensation in FY2025; in FY2024, her salary and total compensation were $137,500, with no other compensation. No bonuses or equity awards were reported for these executives in either year.

For the 12 months ended December 31, 2025 and 2024, director compensation consisted solely of cash fees, with no reported stock, option, incentive-plan, pension/deferred-compensation, or other compensation. Gail Cassell received $15,000 each year; Richard Cohen and Ann MacDougall each received $25,000 each year; and William Chin received $60,000 each year, including advisory compensation.

Executive agreements and consulting arrangement

Vlock’s agreement provides for a $525,000 annual base salary, payable after an IPO or a private equity investment exceeding $10 million. It has an initial three-year term and automatic annual renewal, with an annual bonus determined by committee. Following a qualifying termination in connection with a change in control, he is eligible—subject to a release—for 150% of base salary, 150% of his most recently paid or approved annual bonus, 18 months of continued health benefits, and full vesting of unvested equity.

Thomas’s agreement provides for a $100,000 consulting fee over three months before his CFO employment begins upon IPO completion. His stated post-IPO terms include a $400,000 annual salary and a committee-determined annual bonus. The agreement also allows for consulting fees to be deferred or converted into stock and, subject to conditions, for remaining fees to be paid in cash after a capital raise exceeding $25 million.

De los Reyes provides business-development and corporate-strategy services through BiotechPartnering Solutions, LLC. The 12-month agreement, renewable by mutual agreement, provides a $25,000 monthly retainer and an option to purchase 100,000 common shares at $0.06 per share.

Equity awards and compensation plans

As of June 30, 2026, the executives’ listed options all had a $4.04 exercise price and an August 31, 2033 expiration date; no unvested stock awards were reported. Vlock held options for 58,000 shares (54,778 exercisable and 3,222 unexercisable). Thomas held 328,425 options: 34,800 under one grant (32,867 exercisable and 1,933 unexercisable) plus 293,625 reported exercisable. De los Reyes held 191,400 options: 23,200 under one grant (21,911 exercisable and 1,289 unexercisable) plus 168,200 reported exercisable. The latter Thomas and de los Reyes grants began vesting immediately, with one-third initially vesting and the balance monthly over 24 months; the other grants began vesting after the first anniversary, with one-third vesting then and the balance monthly over 24 months.

At December 31, 2025, Cassell, Cohen, and MacDougall each held options covering 11,600 common shares. Chin held options covering 281,213 shares, including 11,600 for board nominee services; he received no option awards for advisory services in 2025 or 2024.

The 2023 Equity Incentive Plan authorizes up to 2.5 million common shares and permits options, stock appreciation rights, restricted stock, RSUs, performance awards, and other awards. Option and SAR exercise prices generally cannot be below fair market value at grant, and options generally have a maximum 10-year term. Incentive awards may use company-wide or business-unit goals, measured absolutely or relative to peers or indices. The board may adjust performance calculations for numerous items, including restructuring, foreign exchange, accounting or tax changes, acquisitions and divestitures, stock-based compensation, bonuses, and goodwill or intangible-asset impairments—permitting performance measures to exclude potentially material costs or events.

In corporate transactions, awards may be assumed, continued, or substituted. If they are not, awards held by current participants generally accelerate in full before closing, contingent on the transaction; awards held by non-current participants generally terminate if not exercised before closing. The plan administrator may instead provide transaction-value payments for certain terminating awards. Change-in-control acceleration is not automatic unless specified in an award or other written agreement. Vested SARs generally remain exercisable for three months after service termination, 12 months after disability, or 18 months after death; termination for cause generally ends exercise rights immediately, and no exercise may extend beyond the award term. The board may amend, suspend, or terminate the plan subject to participant-rights protections and stockholder approval for certain material amendments; incentive stock options cannot be granted after the tenth anniversary of plan adoption.

Planned post-offering governance and compensation

After the IPO, the Compensation Committee will review and approve or ratify NEO compensation. The company expects to develop a committee-approved, performance-based cash bonus plan and enter into NEO agreements providing severance for qualifying termination without cause or resignation for good reason. Enhanced benefits during a change-in-control period—from three months before through 12 months after the change—are expected to include full vesting of time-based equity awards, subject to an effective release. No performance-based equity awards had been granted as of the disclosure.

Planned annual director fees are $30,000 per director, with additional fees for committee roles: chair fees of $15,000 for Audit, $10,000 for Compensation, and $8,000 for Nominating & Governance; membership fees of $7,500, $5,000, and $4,000, respectively. Option grant values will be set at the offering by the Compensation Committee, and eligible non-employee directors may be reimbursed for reasonable meeting-related travel. Annual compensation for a non-employee director is capped at $1.0 million, or $750,000 in the first year for a newly appointed or elected director. The company generally provides no executive perquisites and may adopt profit-sharing and 401(k) plans in the future.

Related-party transactions and financing

At June 30, 2026, $2.70 million of principal remained outstanding under loans from the CEO, a CEO family member, and significant shareholders. The aggregate was unchanged from December 31, 2025, and the loans remained outstanding as of the prospectus date.

• Convertible notes — $1.25 million: Werth Family Investment Associates, LLC, $200,000 at 8%; two notes involving CEO Daniel Vlock’s sister Sandra Vlock, $150,000 in aggregate at 8%; and CEO Daniel Vlock, $200,000 at 8% (February 2022), $200,000 at 8% (March 2022), $200,000 at 12% (August 2024), and $300,000 at 12% (February 2025).
• Other notes — $1.45 million: CEO Daniel Vlock, $400,000 at 9%, $250,000 at 12%, $200,000 at 12%, $50,000 at 12%, and $200,000 at 15%; shareholder Gerald Pier, $50,000 at 9%; and Werth Family Investment Associates, LLC, $300,000 at 15%.

Extensions and conversion terms

Many related-party notes have been extended repeatedly rather than repaid. Most recently disclosed maturities generally fall in 2027–2028, although certain notes remain due in 2026, including Gerald Pier’s $50,000 note and a $200,000 CEO note issued in November 2023. After June 30, 2026, the CEO’s $200,000 August 2024 convertible note was extended from August 6, 2026 to August 6, 2028. Werth’s $200,000 2021 convertible note was extended to October 21, 2027, and its $300,000 note to October 25, 2027.

Convertible notes are expected to convert into common stock upon completion of the offering. Several carry conversion terms of 75% of the price in a qualifying future equity financing, a 25% discount. Financing thresholds are generally $25 million before the first anniversary and $5 million thereafter; one CEO note specifies $10 million before the first anniversary and $5 million thereafter. The filing describes the terms of later convertible notes as similar to existing notes.

Related-party equity purchases and investor implications

From July 2023 through May 2026, the company issued CEO Daniel Vlock approximately 464,132 common shares for stated proceeds of approximately $2.566 million. Shares were issued at $5.27 per share in 2023–2024, at $4.69 per share in 2025 and February 2026, and at $10 per share in April and May 2026. The latter issuances comprised 15,000 shares for approximately $150,000 and 30,000 shares for approximately $300,000.

The outstanding related-party borrowing, repeated maturity extensions, and interest rates ranging from 8% to 15% indicate continued reliance on financing from insiders and related parties. The arrangements raise governance and conflict-of-interest considerations, while discounted conversion terms could dilute existing shareholders.

Principal stockholders and offering dilution

The ownership table is as of July 31, 2026, and reflects the offering assuming no exercise of the underwriters’ option. Common shares outstanding increase from 5,104,132 before the offering to 8,299,557 immediately afterward, an increase of 3,195,425 shares (about 62.6%). Beneficial ownership figures also include applicable options exercisable within 60 days and shares underlying convertible notes converting at the offering; therefore, reported ownership percentages are not calculated solely from issued and outstanding shares.

Founder Daniel Vlock remains the controlling beneficial owner after the offering. His reported ownership rises from 4,496,009 shares (87.1%) before to 4,633,385 shares (55.8%) after the offering. His holdings include directly held shares and vested options, as well as 3,814,377 shares held through KLP OBP LLC, over which he has dispositive power. The LLC is owned by Vlock and three family members.

Other significant holders include Peter Werth, whose beneficial ownership increases from 535,623 shares (10.5%) before the offering to 568,967 shares (6.9%) after, including applicable options and convertible-note shares, and Dr. Gerald Pier, who holds 627,850 shares, with reported ownership declining from 11.2% to 7.6% after the offering.

The seven directors, executive officers, and director nominees as a group hold 5,331,847 shares (88.9%) before and 5,469,223 shares (65.9%) after the offering. The group’s reported holdings include 893,838 options exercisable for common shares. The company reports that 1,419,388 total options were issued to management, including directors and nominees.

The offering materially dilutes existing holders’ reported percentages, but Vlock retains majority beneficial ownership at 55.8%. Because the ownership figures incorporate options and convertible securities, they should not be treated as equivalent to currently issued shares or as a standalone measure of economic ownership.

Capital Stock and Stockholder Rights

Upon closing of the offering, ALPX will have 110,000,000 authorized shares, each with a par value of $0.0001: 100,000,000 common shares and 10,000,000 preferred shares. As of June 30, 2026, 5,104,132 common shares were outstanding and held of record by four stockholders.

Each common share carries one vote, with no cumulative voting. Common holders are entitled to dividends and distributions upon liquidation, subject to the rights of any outstanding preferred stock. The board may issue authorized but unissued common shares without further stockholder approval, subject to NYSE American listing standards. Any future issuance of preferred stock could adversely affect common-stock rights.

Takeover and Governance Provisions

The amended charter and bylaws, which will take effect before the offering closes, include provisions that may make a change in control or stockholder-led governance changes more difficult:

• Special stockholder meetings may be called only by specified officers or by a majority-board resolution.
• Stockholders must provide advance notice of nominations and proposals, and may not act by written consent.
• The board will be divided into three classes with staggered three-year terms.
• Directors may be removed only for cause, with approval from at least two-thirds of outstanding voting power.
• Amendments to these charter provisions also require at least two-thirds approval.

In addition, Delaware General Corporation Law Section 203 generally restricts business combinations with an interested stockholder owning 15% or more for three years, absent specified approval or an exception. Together, these provisions could deter unsolicited acquisitions, premium offers, or stockholder efforts to change the board or management, potentially limiting stockholder influence and takeover-related share-price movements.

Litigation Forum, Listing, and Transfer Agent

The charter will generally designate Delaware courts as the exclusive forum for specified internal-affairs and corporate-law claims, and the federal District of Delaware for Securities Act, Exchange Act, and other claims subject to exclusive federal jurisdiction. A court in another jurisdiction could find these provisions unenforceable, potentially increasing litigation costs.

ALPX common stock is not currently listed on an exchange. The company has applied to list the stock on NYSE American under ticker symbol ALPX. VStock Transfer LLC will serve as transfer agent and registrar upon the offering’s close.

Shares Eligible for Future Sale

The company has no prior public market. It plans to list its common stock on the NYSE American, but an active market may not develop or be sustained.

After the offering, approximately 8,299,557 common shares are expected to be outstanding. This estimate is based on shares outstanding at June 30, 2026 and assumes the sale of 3,000,000 offering shares, no exercise of the underwriters’ overallotment option, and conversion of outstanding convertible notes into 195,425 shares.

Shares sold in the offering generally will be freely tradable, except for shares purchased by affiliates. Most other outstanding shares are restricted securities and are subject to lock-up agreements or other resale restrictions. The company, its directors and executive officers are subject to 365-day lock-ups; other stockholders and option holders are generally subject to 180-day lock-ups. These restrictions are subject to specified exceptions and, in some cases, underwriter consent. When restrictions expire, substantially all locked-up shares may become eligible for sale, creating a potential supply overhang that could put pressure on the stock price.

Affiliate resales under Rule 144 are subject to volume, manner-of-sale, notice and public-information requirements. Immediately after the offering, the stated 1% volume limit is approximately 83,505 shares per three-month period, or the applicable average weekly trading volume, whichever is greater. Nonaffiliate holders may be eligible for less restrictive Rule 144 sales after applicable holding periods and reporting requirements. Rule 701 compensatory shares generally cannot be sold until 90 days after the prospectus and remain subject to applicable lock-ups.

Additional potential sources of future share supply include shares issuable under options, warrants and equity plans, as well as shares the company may issue for acquisitions, investments or other corporate purposes. Significant transactions could involve substantial share issuance and may include registration rights. The company intends to file Form S-8 registration statements shortly after the prospectus to register equity-plan shares, facilitating public resale subject to applicable affiliate restrictions.

U.S. Federal Income Tax Consequences for Non-U.S. Holders

The company has never declared or paid cash dividends and does not expect to do so in the foreseeable future. If it does make a distribution, the portion treated as a dividend generally is subject to 30% U.S. withholding tax, unless a tax treaty provides a lower rate and the holder supplies required documentation. Dividends effectively connected with a U.S. trade or business are generally taxed on a net-income basis at regular U.S. rates; a corporate holder may also owe a 30% branch-profits tax, potentially reduced by treaty. Distributions exceeding the company’s earnings and profits generally reduce the holder’s stock basis first, with any excess treated as gain from a disposition.

Non-U.S. Holders generally are not subject to U.S. federal income tax on gains from selling the company’s stock. Exceptions include gains effectively connected with a U.S. trade or business; certain gains of an individual present in the United States for at least 183 days during the tax year, subject to additional conditions; and gains if the company is or was a U.S. real property holding corporation (USRPHC). The company believes it has not been, is not, and does not anticipate becoming a USRPHC. That determination generally depends on whether U.S. real property accounts for at least half of the fair market value of the relevant business assets. If USRPHC rules apply, a holder owning no more than 5% may generally avoid tax if the stock is regularly traded on an established market; the company does not assure that this trading condition will continue. Taxable gains for U.S.-connected holders generally are taxed at regular U.S. rates. Certain individuals present in the United States for at least 183 days may instead face a 30% rate, subject to treaty relief.

FATCA may require 30% withholding on dividends and, under the rules described, gross proceeds from dispositions paid to certain foreign financial institutions or non-financial foreign entities that fail applicable reporting, certification, or exemption requirements. Intergovernmental agreements may modify those requirements. Proposed Treasury regulations, on which taxpayers generally may rely pending final regulations, would eliminate FATCA withholding on gross disposition proceeds if finalized as proposed.

The company has not sought an IRS ruling, and tax authorities may challenge its interpretations. Tax laws and related guidance may change, potentially with retroactive effect. The discussion does not cover numerous investor categories subject to special tax rules or non-federal-income-tax consequences; investors are advised to consult their own tax advisers.

IPO Underwriting Terms

ThinkEquity LLC is the sole named representative of the underwriters. The underwriting table’s share allocations, public offering price, gross proceeds, underwriting discounts, and net proceeds are blank in the provided section, so the offering’s total size and proceeds cannot be determined. The underwriting commission is 7.0% of the public offering price. ALPX also pays a 1.0% non-accountable expense allowance and has advanced $50,000 for accountable expenses, with any unused amount to be returned. Estimated offering expenses are approximately $1.9 million, excluding underwriting discounts and commissions. The company will reimburse certain underwriter expenses, including legal fees capped at $212,500.

The underwriters’ purchase obligations are subject to closing conditions; if they purchase any shares, they must purchase all shares offered. The Representative has a 45-day option to buy up to 450,000 additional shares solely to cover over-allotments.

At closing, the Representative or its designees will receive warrants for shares equal to 5% of the shares sold. The warrants are exercisable at 125% of the IPO price, beginning 180 days after the registration statement’s effective date and continuing for 4.5 years. They include registration rights; ALPX bears the related registration costs, except for holders’ underwriting commissions.

Restrictions and Future Engagement Rights

The company, its directors, and executive officers are subject to 365-day lockups after the prospectus date; other stockholders and option holders are subject to 180-day lockups. Customary exceptions apply, and other permitted transactions may require the Representative’s consent.

For 18 months, the Representative has a right of first refusal to serve as exclusive banker, advisor, underwriter, or placement agent for future equity, debt, and equity-linked financings involving ALPX, its successors, or subsidiaries.

Listing and Trading Risks

NYSE American listing under the symbol ALPX is not assured, and completion of the offering depends on listing approval. An active trading market may not develop, and the shares could trade below the IPO price. Underwriters may conduct stabilization and short-covering transactions that temporarily support or maintain the share price, but they do not assure these activities will occur or continue. No operating or historical financial performance metrics are provided in this section.

• Sheppard, Mullin, Richter & Hampton LLP (New York) will provide the opinion on the validity of the common shares being offered.
• Nelson Mullins Riley & Scarborough LLP (Raleigh) represents the underwriters.
• The section discloses no financial metrics, business risks, or strategic developments.

Experts and Auditor Matters

Alopexx’s FY2025 financial statements were audited by CBIZ CPAs P.C. The auditor’s report includes an explanatory paragraph expressing substantial doubt about the company’s ability to continue as a going concern, as discussed in Note 1.

Alopexx’s FY2024 financial statements received an unmodified audit opinion from Marcum LLP. CBIZ acquired Marcum’s attest business assets on November 1, 2024. This section provides no financial metrics or other business developments.

Alopexx filed an S-1 registration statement with the SEC; the prospectus is incomplete without the registration statement and its exhibits. After the offering closes, the company will become subject to Exchange Act reporting requirements and expects to make its SEC filings available free of charge on its website after filing. This section provides no financial metrics, material business developments, or company-specific risks.

Alopexx — financial statements and operating outlook

Business and operating performance

Alopexx is a pre-revenue, clinical-stage biotechnology company developing PNAG-targeting therapeutics, including AV0328 and the F598 antibody. It has one operating and reportable segment, no long-lived assets, and no revenue in either the three or six months ended June 30, 2026 or the comparable 2025 periods. Management says limited operations reflect liquidity and funding constraints; performance is assessed primarily through research and development (R&D) and general and administrative (G&A) expenses.

• Q2 2026: R&D expense was $211,175, up from $53,855 in Q2 2025; G&A was $256,981, down from $618,514. Operating loss narrowed to $468,156 from $672,369, and net loss narrowed to $541,829 from $746,042. Interest expense was $73,673 in both quarters.
• H1 2026: R&D expense was $259,925, versus $109,432 in H1 2025; G&A was $604,164, versus $1,277,540. Operating loss narrowed to $864,089 from $1,386,972; interest expense rose to $146,536 from $142,295; and net loss narrowed to $1,010,625 from $1,529,267. The improvement reflects lower G&A despite higher R&D; the filing does not explain the drivers. Loss per share was $0.11 versus $0.15 for Q2 and $0.20 versus $0.31 for H1.
• Basic and diluted weighted-average shares were the same because potential shares were anti-dilutive. At June 30, 2026, 2,669,388 potential shares were excluded, including 1,419,388 stock options and 1,250,000 shares issuable on convertible notes. H1 stock-based compensation was $79,374, down from $742,974.

Cash flow, balance sheet, and financing

H1 2026 net cash used in operating activities was $530,883, compared with $626,962 in H1 2025; capital expenditures were $0 in both periods. Related-party stock issuances provided $600,000 in H1 2026, versus $200,000 in H1 2025. Cash increased by $69,117 to $97,586 at June 30, 2026; cash was held at one financial institution.

At June 30, 2026, total assets were $981,003 (versus $911,886 at December 31, 2025), including cash and $883,417 of deferred offering costs. Goodwill was $0, and intangible assets other than goodwill were $0. Total equity was a deficit of $6,422,390 (versus a $6,091,139 deficit); tangible common equity was $(6,422,390). Total liabilities were $7,403,393, including $5,036,726 current and $2,366,667 long-term liabilities. Working capital deficiency was approximately $4.1 million, compared with $5.3 million at year-end; management says the apparent improvement primarily reflects reclassification, not better operations.

Shares outstanding increased from 5,027,149 at year-end 2025 to 5,104,132 at June 30, 2026. H1 issuances included 76,983 shares to related parties for approximately $600,000. Related-party notes and convertible notes totaled $2.65 million, with approximately $954,000 of related-party accrued interest (up from approximately $809,000). Related-party debt generally bears 8%–15% interest. A separate $50,000 convertible note bears 8%; accrued interest was $17,939. Most debt is due in 2026–2028. Payables and accrued expenses were $3.065 million, including board, consultant, accounting and legal fees, and related-party license accruals.

Collaborations, licenses, and material developments

Under its BCI collaboration for AV0328, Alopexx received $666,667, recorded as non-current deferred revenue. The license and related development and regulatory work are treated as one performance obligation satisfied over time; no revenue had been recognized by June 30, 2026, and management does not expect to recognize the balance within the following 12 months. Additional contingent payments and milestones are excluded from the transaction price until uncertainty is resolved; future royalties depend on sales. The company’s BWH licenses for AV0328 and F598 also involve annual pre-commercial fees, royalties, potential milestones, development obligations, and BWH control of patent prosecution. Licensed patent rights expire across 2026–2033.

On August 7, 2026, Alopexx and BCI terminated a separate stock purchase agreement for a contemplated $1.5 million investment (300,000 shares at $5 per share). No further consideration or obligations are due under that agreement; the termination does not affect the separate licensing arrangements.

After quarter-end, Alopexx extended the CEO’s $200,000 note maturity to August 6, 2028. On August 17, it received $350,000 under a related-party note bearing 12% annual interest, maturing in 2028 or upon specified future financings. The Xenothera claim seeking, among other relief, €120 million was rejected; the court ordered Xenothera to pay €25,000, received in February 2026 and recorded in H1 G&A.

Risks and accounting

Accumulated deficit was $17.7 million. With recurring losses, no revenue, limited cash, and no committed new financing, management states substantial doubt exists about the company’s ability to continue as a going concern over the 12 months following issuance. Continued operations depend on raising capital and advancing candidates through development, regulatory approval, and commercialization; the deferred offering costs may also be at risk if an offering is unsuccessful. Alopexx maintained a full valuation allowance against deferred tax assets and recorded no tax provision or benefit (0% effective tax rate). The interim statements are unaudited; management identifies estimates including accrued expenses, deferred offering cost recoverability, collaboration revenue recognition, and equity awards.

Business, results, and liquidity

Alopexx is a pre-revenue, clinical-stage biotechnology company developing immune-mediated therapeutics targeting PNAG, including the AV0328 vaccine and F598 antibody. It operates as one U.S. reportable segment. With no revenue in FY2025 or FY2024, it expects continued losses while developing products and pursuing regulatory approval and commercialization.

The auditor issued an unmodified opinion but included a going-concern explanatory paragraph, citing substantial doubt about Alopexx’s ability to continue operating for the 12 months following issuance of the March 23, 2026 financial statements. At December 31, 2025, cash was $28,469, down from $268,597 a year earlier, and the working-capital deficiency was approximately $5.3 million, compared with $4.9 million. Management says additional financing is needed, but no new financing commitments were secured. The company has relied on equity and related-party notes; market volatility and geopolitical events may affect financing availability.

FY2025 operating expenses fell 17.7% to $2.3171 million from $2.8148 million: R&D was $198,406 from $223,998, and G&A was $2.1187 million from $2.5908 million. Operating loss was $2.3171 million from $2.8148 million. Net interest expense increased to $291,258 from $245,811, while net loss improved to $2.6084 million from $3.0606 million. Basic and diluted loss per share was $0.53 from $0.63; weighted-average shares were 4,947,002 from 4,874,134. No cost of revenue or segment-level revenue or profit was reported.

Operating cash used was $1.1401 million in FY2025, compared with $481,234 in FY2024. The prior-year cash flow benefited from a $666,667 increase in deferred revenue; FY2025 had no such benefit. Capital expenditures were $0 in both years, and investing cash flow was nil. Financing cash provided was $900,000 from $700,000, including related-party common-stock proceeds of $600,000 from $500,000 and long-term related-party note proceeds of $300,000 from $200,000.

Balance sheet, debt, and equity

At December 31, 2025, total assets were $911,886 versus $1,152,014; total stockholders’ deficit was $6.0911 million versus $5.1263 million. Goodwill and other intangible assets were not reported; tangible common equity was therefore also a deficit of $6.0911 million. Total liabilities rose to $7.0030 million from $6.2783 million, including current liabilities of $6.2030 million from $6.0783 million. Accumulated deficit was $16.713 million, up from $14.105 million. Accounts payable and accrued expenses were $2.811 million from $2.678 million; notable 2025 accruals included business-development consultant fees of $625,000, board fees of $583,745, and license fees of $516,250 to Alopexx Pharmaceuticals and $308,749 to Alopexx Vaccine.

Disclosed note principal totaled $2.70 million at year-end: $1.25 million of convertible notes and $1.45 million of related-party notes payable, versus total principal of $2.40 million in 2024. Interest rates range from 8% on general convertible notes, 12% on CEO notes, and 9%–15% on related-party notes payable. Several notes have conversion provisions at 75% of the price in qualifying future financings. Accrued interest on convertible notes was $15,956 on the non-related-party note and $286,795 on related-party convertible notes, versus $11,955 and $175,036. Accrued interest on related-party notes payable was $522,625, versus $347,125. The balance sheet reported related-party notes payable of $1.45 million current and $800,000 long-term; related-party accrued interest totaled $809,420, up from $522,161. These balances and substantial interest accruals underscore reliance on insider funding and refinancing risk. Subsequent to year-end, five notes’ maturities were extended by 24 months, moving 2026 maturities to corresponding dates in 2028; other terms were unchanged.

Common shares outstanding increased to 5,027,149 at FY2025 year-end from 4,899,218 at its start. In FY2024, shares increased from 4,804,342 to 4,899,218. FY2025 related-party issuances were 127,931 shares for approximately $600,000 at $4.69 per share, compared with 94,876 shares for $500,000 in FY2024. Stock-based compensation was $1.0435 million from $1.4859 million; 1,419,388 options remained outstanding, of which 1,053,485 were exercisable. No options were granted in 2025.

Collaboration, licenses, and other matters

The BCI collaboration covers co-development and commercialization of AV0328 for prevention of Streptococcus pneumoniae infections in India and other licensed territories, with additional indications subject to approval. The $666,667 nonrefundable upfront payment remained deferred at both year-ends because the combined license-and-R&D performance obligation was not yet sufficiently satisfied; it is recognized over time. Potential additional payments include two $666,667 indication payments, up to $3 million for preclinical work and specified milestones, and up to $4.5 million in development and regulatory milestones. These contingent amounts were excluded from the transaction price because they were constrained variable consideration. Future royalties are single digits for public-market sales and low teens for private-market sales, recognized as sales occur. A contemplated $1.5 million purchase of 300,000 shares at $5 per share is separate equity financing, not revenue consideration; an amendment tied the investment to an alternative funding event and independent valuation criteria.

Alopexx’s BWH licenses for AV0328 and F598 carry annual pre-commercial fees, low-single-digit royalties, potential low-seven-figure milestones, and a low-double-digit share of sublicense income. Patent rights expire over 2025–2033; the BCI agreement’s last covered patent is expected to expire in 2040. Both arrangements include diligence and termination provisions.

The Xenothera claim seeking a license or €120 million in damages (reported as $140.790 million at year-end) was rejected in full; Xenothera was ordered to pay Alopexx €25,000. The company recorded a full valuation allowance against deferred tax assets, leaving net deferred tax assets at zero. Its preliminary prospectus refers to a proposed offering of 3,000,000 common shares through ThinkEquity; price and proceeds were not provided. Alopexx identified no critical audit matters; the auditor did not audit internal-control effectiveness.