Annual Report for Fiscal Year Ending December 31, 2025 (Form 10-K)

Management's Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with our consolidated financial statements and the related notes and other financial information included elsewhere in this Annual Report on Form 10-K.

In addition to historical financial information, the following discussion contains forward-looking statements that reflect our plans, estimates, beliefs, and expectations, and involve risks and uncertainties. Factors that could cause or contribute to these differences include those discussed below and elsewhere in this Annual Report on Form 10-K, particularly in the sections titled "Special Note Regarding Forward-Looking Statements" and "Risk Factors."

Overview

We are a biopharmaceutical company advancing the next generation platform of targeted immunotherapies aimed at complement-mediated neuroinflammatory diseases that impact nearly 10 million people worldwide. Building on more than a decade of expertise stopping acute and chronic neuroinflammation at its source, we have demonstrated robust target engagement in the body, brain and eye, and clinical proof of concept in multiple diseases.

Our strategic priorities include advancing two late-stage registrational programs, tanruprubart toward our first approval in Guillain-Barré Syndrome, or GBS, and vonaprument toward pivotal data in geographic atrophy, or GA, as well as developing ANX1502, a novel oral small molecule for autoimmune conditions.

Tanruprubart is an investigational targeted immunotherapy delivered in a single infusion to rapidly halt aggressive neuroinflammation and damage in GBS, an acute, rare, neuromuscular emergency that annually affects ~150,000 people worldwide. There are currently no therapies approved by the FDA for GBS and no substantial evidence of effectiveness from the current standard of care. In the placebo-controlled Phase 3 trial, approximately 90% of GBS patients treated with tanruprubart improved by week 1 and more than twice as many treated patients achieved a normal state of health at week 26. Tanruprubart has consistently demonstrated rapid and sustained functional improvements across a comprehensive data package. The open-label FORWARD study in the U.S. and Europe is ongoing and designed to support a broad intended label for the treatment of GBS and further expand the use of tanruprubart across geographies. We continue to engage with applicable EU and U.S. regulators to advance tanruprubart towards registration worldwide. We filed the Marketing Authorization Application, or MAA, with the European Medicines Agency, or EMA, for tanruprubart for the treatment of GBS in January 2026. We plan to submit a biologics license application, or BLA, to the FDA for GBS in 2026. Tanruprubart has been granted Fast Track and orphan drug designation for the treatment of GBS from the FDA. Tanruprubart has also been granted orphan designation from the EMA.

Vonaprument is an investigational neuroprotective inhibitor of C1q and the classical complement cascade delivered intravitreally for GA, a leading cause of blindness affecting more than eight million people worldwide. There are no approved therapies for GA targeting the preservation of vision. Vonaprument is the only investigational therapy in GA to show significant vision preservation on assessments of best corrected visual acuity, or BCVA, and low luminance visual acuity, or LLVA, demonstrating significant protection from vision loss in both normal and low light conditions, as well as significant preservation of central retinal photoreceptors necessary for visual acuity. In the Phase 2 ARCHER trial, vonaprument also reduced risk of 15-letter vision loss by more than 70%.

In July 2025, we completed enrollment of 659 patients in ARCHER II, a global, sham-controlled, double-masked Phase 3 trial. The primary endpoint of ARCHER II is the gold standard for visual acuity, measuring proportion of patients with confirmed BCVA ≥15-letter loss at any two consecutive visits through month 15. A secondary endpoint is EZ loss, which is a key anatomic measure of photoreceptor health and function. We plan to report topline data in the fourth quarter of 2026. We have established a global registration path with the FDA and EMA, which supports the potential of vonaprument to be the first treatment approved in both Europe and the U.S. for the protection of vision in patients with GA. The single-study program will be analyzed as two sub-studies in the U.S. in accordance with the FDA's two-trial recommendation. Vonaprument is the first and only therapeutic candidate for the treatment of GA to receive Priority Medicine, or PRIME, designation by the EMA, which provides early and proactive support to developers of promising medicines that may offer a major therapeutic advantage over existing treatments or benefit to patients without treatment options. Vonaprument was also selected by the EMA for the Product Development

Coordinator Pilot launched in July 2025 to help PRIME designation holders efficiently navigate regulatory interactions including expedited scientific advice, MAA submission readiness activities, and ad-hoc queries throughout the development program.

ANX1502 is a novel oral small molecule inhibiting the activated form of C1s, an enzyme carried by C1q to initiate the classical cascade, which we believe is first-in-kind and has the potential to offer the advantages of selective upstream classical complement inhibition with the convenience and flexibility of oral administration. In a Phase 1 single-ascending dose and multiple-ascending dose clinical trial in healthy volunteers designed to evaluate the safety, tolerability, PK and PD, ANX1502 was generally well tolerated across cohorts with no serious adverse events, achieved target levels of active drug and showed supportive impact on a PD biomarker of complement activity. We are evaluating an enteric-coated tablet formulation of ANX1502 in an ongoing POC study in patients with cold agglutinin disease, or CAD. We have observed drug levels at and exceeding the pre-defined target in fasted CAD patients. Dosing is ongoing to enhance our understanding of ANX1502's profile and we plan to provide an update upon study completion in 2026.

We were incorporated in March 2011 and commenced operations later that year. To date, we have focused primarily on performing research and development activities, hiring personnel and raising capital to support and expand these activities. We do not have any products approved for sale, and we have not generated any revenue from product sales. We have incurred net losses each year since our inception. Our net losses were $206.7 million and $138.2 million for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, we had an accumulated deficit of $917.4 million and cash and cash equivalents and short-term investments of $238.3 million.

Components of Operating Results

Revenue

Our product candidates are not approved for commercial sale. We have not generated any revenue from sales of our product candidates and do not expect to do so in the foreseeable future and until we complete clinical development, submit regulatory filings and receive approvals from applicable regulatory bodies for such product candidates, if ever.

Operating Expenses

Research and Development

Research and development expenses account for a significant portion of our operating expenses. Research and development expenses consist primarily of direct and indirect costs incurred for the development of our product candidates.

Direct expenses include:

Indirect expenses include:

We record research and development expenses as incurred. Payments made to other entities are under agreements that are generally cancelable by us. Advance payments for goods or services to be received in future periods for use in research and development activities are deferred as prepaid expenses. The prepaid amounts are then expensed as the related services are performed. At this time, we cannot reasonably estimate or know the nature, timing and estimated costs of the efforts that will be necessary to complete the development of, and obtain regulatory approval for, any of our product candidates.

We expect our future research and development expenses to increase as we pursue regulatory approval of our product candidates, continue to advance our product candidates through late-stage clinical trials, invest in capabilities to prepare for commercialization including manufacturing, and hire additional personnel to support our organization. The process of conducting the necessary clinical research, development and manufacturing to obtain regulatory approval is costly and time-consuming, and the successful development and approval of our product candidates is highly uncertain.

General and Administrative

General and administrative expenses consist primarily of compensation and personnel-related expenses (including stock-based compensation) for our personnel in executive, finance and other administrative functions. General and administrative expenses also include professional fees paid for accounting, legal and tax services, allocated expenses for facilities and depreciation and other general and administrative costs.

We expect our general and administrative expenses to increase as we continue to support our research and development activities, grow our business, advance our product candidates in late-stage clinical trials and toward regulatory approval and commercialization activities, and operate as a public company.

Interest and Other Income, Net

Interest and other income, net, primarily consists of interest income earned on our cash equivalents and short-term investments.

Results of Operations

Comparison of the Years Ended December 31, 2025 and 2024

The following tables summarize our results of operations for the periods presented:

Research and Development Expenses

Research and development expenses increased by $65.3 million, or 55%, for the year ended December 31, 2025 compared to the year ended December 31, 2024. The change was attributable to an increase of $27.1 million in contract manufacturing expenses supporting the tanruprubart global regulatory submissions, as well as the manufacturing technology transfer of vonaprument to a commercial-ready facility. In addition, direct clinical and nonclinical outside services costs increased by $21.9 million associated with the vonaprument Phase 3 ARCHER II trial in GA and the initiation of the tanruprubart FORWARD study in GBS. Compensation and personnel-related expenses (including stock-based compensation) increased by $10.0 million, driven by higher headcount, and consulting and professional services expenses increased by $6.0 million primarily due to global regulatory submissions and the ongoing ARCHER II trial.

General and Administrative Expenses

General and administrative expenses decreased by $2.9 million, or 8%, for the year ended December 31, 2025 compared to the year ended December 31, 2024 primarily driven by ongoing corporate efficiencies and disciplined prioritization of resources resulting in a $2.6 million decrease in consulting and professional services costs. In addition, compensation and personnel-related expenses decreased by $1.2 million mainly due to the full amortization of previously granted high fair value stock options, partially offset by higher headcount. The overall decrease in general and administrative expenses was partially offset by other expenses which increased by $0.9 million due to cloud-based infrastructure costs.

Interest and other income, net

Interest and other income, net decreased by $6.2 million for the year ended December 31, 2025 compared to the year ended December 31, 2024. The decrease was primarily due to lower average cash and investment balances.

Liquidity and Capital Resources

Sources of Liquidity

Due to our significant research and development expenditures, we have generated operating losses each year since our inception.

To date, we have funded our operations primarily through the sale of equity securities including, most recently, the public offering of approximately $86.3 million of common stock and pre-funded warrants. In addition, on March 30, 2026, we entered into a sales agreement with TD Cowen, or the 2026 Sales Agreement, pursuant to which we may offer and sell, from time to time through TD Cowen, at our option, shares of our common stock having an aggregate offering price of up to $150.0 million. As of December 31, 2025, we had available cash and cash equivalents and short-term investments of $238.3 million and an accumulated deficit of $917.4 million.

Historical Cash Flows

Cash Flow from Operating Activities

Cash used in operating activities for the year ended December 31, 2025 was $186.4 million, which consisted of a net loss of $206.7 million, partially offset by $16.1 million in non-cash charges and a net change of $4.2 million in our operating assets and liabilities. The non-cash charges consisted of stock-based compensation of $16.4 million, depreciation and amortization of $2.2 million, and reduction in the carrying amount of right-of-use assets of $1.5 million, partially offset by accretion of discount on available-for-sale securities of $4.0 million.

Cash used in operating activities for the year ended December 31, 2024 was $118.0 million, which consisted of a net loss of $138.2 million, partially offset by $13.8 million in non-cash charges and a net change of $6.4 million in our operating assets and liabilities. The non-cash charges consisted of stock-based compensation of $19.4 million, depreciation and amortization of $2.2 million, and reduction in the carrying amount of right-of-use assets of $1.3 million, partially offset by accretion of discount on available-for-sale securities of $9.1 million.

Cash Flow from Investing Activities

Cash provided by investing activities for the year ended December 31, 2025 was $190.1 million, which consisted of $402.4 million of proceeds from maturities of available-for-sale securities, partially offset by $212.2 million of purchases of available-for-sale securities.

Cash used in investing activities for the year ended December 31, 2024 was $218.8 million, which consisted of $583.9 million of purchases of available-for-sale securities, partially offset by $365.1 million of proceeds from maturities of available-for-sale securities.

Cash Flow from Financing Activities

Cash provided by financing activities for the year ended December 31, 2025 was $108.9 million, which consisted of $80.5 million of net proceeds from the issuance of common stock and pre-funded warrants under our 2025 Financing, $27.4 million of net proceeds from the issuance of common stock under our 2024 ATM program and $1.0 million of proceeds from the exercise of common stock options and employee stock purchase plan purchases.

Cash provided by financing activities for the year ended December 31, 2024 was $161.2 million, which consisted of $116.8 million of net proceeds from the issuance of common stock and pre-funded warrants under our 2024 financing, $42.8 million of net proceeds from the issuance of common stock under our 2021 and 2024 ATM programs and $1.6 million of proceeds from the exercise of common stock options and employee stock purchase plan purchases.

Funding Requirements

We use our cash to fund operations, primarily to fund our clinical trials, research and development expenditures and related personnel costs. We expect our future research and development expenses to increase as we pursue regulatory approval of our product candidates, continue to advance our product candidates through late-stage clinical trials, invest in capabilities to prepare for commercialization including manufacturing, and hire additional personnel to support our organization. In addition, we expect our general and administrative expenses to increase as we continue to support our research and development activities, grow our business, advance our product candidates in late-stage clinical trials and toward regulatory approval and commercialization activities, and operate as a public company. The timing and amount of our operating expenditures will depend on many factors, including:

Based upon our current operating plan, we believe that our existing cash and cash equivalents and short-term investments will enable us to fund operating expenses into the second half of 2027. We will require substantial additional financing to achieve our goals, and a failure to obtain this necessary capital when needed on acceptable terms, or at all, could force us to delay, limit, reduce or terminate our product development programs, commercialization efforts or other operations. We have based this estimate on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we expect. We will be required to seek additional funding in the future until such time, if ever, as we can generate substantial product revenue, and currently intend to do so through public or private equity offerings or debt financings, credit or loan facilities, collaborations or a combination of one or more of these funding sources. We may also need to seek additional funds sooner than planned as result of changes in our development plans and regulatory requirements to support registration of our product candidates. Additional funds may not be available to us on acceptable terms or at all. If we fail to obtain necessary

capital when needed on acceptable terms, or at all, we could be forced to delay, limit, reduce or terminate our product development programs, commercialization efforts or other operations. If we raise additional funds by issuing equity securities, our stockholders will suffer dilution and the terms of any financing may adversely affect the rights of our stockholders. In addition, as a condition to providing additional funds to us, future investors may demand, and may be granted, rights superior to those of existing stockholders. Debt financing, if available, is likely to involve restrictive covenants limiting our flexibility in conducting future business activities, and, in the event of insolvency, debt holders would be repaid before holders of our equity securities received any distribution of our corporate assets.

2025 Financing

In November 2025, we raised net proceeds of approximately $80.5 million after deducting underwriting discounts and offering expenses through the sale of 29,423,075 shares of our common stock at a price of $2.60 per share and pre-funded warrants to purchase an aggregate of 3,750,000 shares of common stock at a price of $2.599 per share, which equals the per share offering price for the shares of common stock less the $0.001 exercise price for each pre-funded warrant.

2024 Financing

In June 2024, we raised net proceeds of approximately $116.8 million after deducting underwriting discounts and offering expenses through the sale of 13,001,120 shares of our common stock at a price of $6.25 per share and pre-funded warrants to purchase an aggregate of 7,000,000 shares of common stock at a price of $6.249 per share, which equals the per share offering price for the shares of common stock less the $0.001 exercise price for each pre-funded warrant. In March 2026, we issued an aggregate of 4,499,124 shares of common stock upon the cashless exercise of pre-funded warrants to purchase 4,500,000 shares of common stock. As of the date of these consolidated financial statements, pre-funded warrants to purchase up to 2,500,000 shares of common stock remained outstanding from the 2024 Financing.

2023 Financing

In December 2023, we raised net proceeds of approximately $117.0 million after deducting underwriting discounts and offering expenses through the sale of 25,035,000 shares of our common stock at a price of $2.880 per share and pre-funded warrants to purchase an aggregate of 18,379,861 shares of common stock at a price of $2.879 per share, which equals the per share offering price for the shares of common stock less the $0.001 exercise price for each pre-funded warrant. We issued an aggregate of 5,243,400 and 965,427 shares of common stock upon cashless and cash exercise of these pre-funded warrants in February 2024 and April 2024, respectively.

2022 Financing

In July 2022, we raised net proceeds of approximately $122.5 million after deducting fees and expenses through the sale of an aggregate of 9,013,834 shares of common stock, pre-funded warrants to purchase up to 24,696,206 shares of our common stock and accompanying common warrants to purchase up to 8,427,508 shares of our common stock. The offering price per share and accompanying common warrant was $3.87125 per share and the offering price per pre-funded warrant and accompanying common warrant was $3.87025 per share, which equals the per share offering price for the shares of common stock less the $0.001 exercise price for each such pre-funded warrant. The pre-funded warrants remain exercisable until exercised in full. The common warrants had an exercise price of $5.806875 per share and, except as described in the next paragraph, expired on June 30, 2025. Both the pre-funded and common warrants were immediately exercisable, subject to beneficial ownership limitations. We issued an aggregate of 19,901 and 2,739,096 shares of common stock upon the cashless exercise of the common warrants and pre-funded warrants in June 2024 and November 2024, respectively.

In June 2025, we and holders of common warrants exercisable for 6,877,622 shares of our common stock entered into amendments to the common warrants held by such holders. The amendments extended the term of the common warrants by one year until June 30, 2026, and removed the cashless exercise option. If all such common warrants are exercised in full for cash (without regard to any applicable ownership limitations), we would receive aggregate gross proceeds of approximately $39.9 million. The remaining common warrants to purchase 1,226,993 shares of our common stock not subject to these amendments expired unexercised on June 30, 2025.

Pre-Funded and Common Warrants

The following summarizes warrant activity during the year ended December 31, 2025:

2026 At the Market (ATM) Program

Pursuant to the 2026 Sales Agreement, we may offer and sell, from time to time through TD Cowen, at our option, shares of our common stock having an aggregate offering price of up to $150.0 million (the "ATM Shares"). The sales of the ATM Shares will be made by any method permitted that is deemed to be an "at-the-market" equity offering as defined in Rule 415(a)(4) promulgated under the Securities Act, including sales made directly on or through the Nasdaq Global Select Market. We agreed to pay TD Cowen a commission of up to 3.0% of the aggregate gross proceeds from any ATM Shares sold by TD Cowen.

2024 ATM Program

In March 2024, we entered into a sales agreement with TD Cowen, as sales agent, pursuant to which we could issue and sell shares of our common stock for an aggregate maximum offering of $100.0 million under an at-the-market offering program, or 2024 ATM program. TD Cowen is entitled to compensation up to 3% of the aggregate gross proceeds for the common stock sold through the 2024 ATM program. During the year ended December 31, 2025 and 2024, we sold 9,740,824 shares and 750,000 shares of common stock, respectively, for net proceeds of approximately $27.4 million and $4.5 million, respectively, after deducting commissions paid to TD Cowen. As of December 31, 2025, approximately $66.9 million remained available for the offer and sale of shares of common stock under the 2024 ATM program. Subsequent to December 31, 2025 and through the date of issuance of these consolidated financial statements, we sold 6,049,762 shares of common stock under the 2024 ATM for net proceeds of approximately $32.8 million, after deducting commissions paid to TD Cowen.

2021 ATM Program

In August 2021, we entered into a sales agreement with TD Cowen, as sales agent, pursuant to which we could issue and sell shares of our common stock for an aggregate maximum offering of $100.0 million under an at-the-market offering program, or 2021 ATM program. TD Cowen is entitled to compensation of up to 3% of the aggregate gross proceeds of the common stock sold through the 2021 ATM program. During the year ended December 31, 2024, we sold 7,576,067 shares of common stock under the 2021 ATM program for net proceeds of approximately $38.4 million, after deducting commissions paid to TD Cowen and other financing costs. The Form S-3 registration statement, which registered the 2021 ATM Program, expired on August 15, 2024. As a result, no shares of common stock may be sold under the 2021 ATM Program.

Off-Balance Sheet Arrangements

Since our inception, we have not engaged in any off-balance sheet arrangements, as defined in the rules and regulations of the SEC.

Critical Accounting Policies and Estimates

Management's discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with U.S. GAAP. The preparation of these consolidated financial statements requires us to make estimates and assumptions for the reported amounts of assets, liabilities, expenses and related disclosures. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making

judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions and any such differences may be material.

While our significant accounting policies are described in more detail in the notes to our consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K, we believe the following accounting policies are the most critical for fully understanding and evaluating our financial condition and results of operations.

Accrued and Prepaid Research and Development Costs

We record accrued expenses for estimated costs of our research and development activities conducted by third-party service providers, which include the conduct of clinical trials and nonclinical studies. We estimate preclinical study and clinical trial expenses based on the services performed pursuant to contracts with research institutions, clinical research organizations, and clinical manufacturing organizations that conduct and manage preclinical studies and clinical trials on our behalf. In recording service fees as either prepaid or accrued costs, we estimate the period over which services will be performed and the level of effort to be expended in each period. The level of judgment required to estimate research and development expenses varies based on the nature of the services being performed and the underlying support obtained. Accordingly, research and development expenses supported by invoices or reports of costs from third-party providers for the services performed do not require us to make significant estimates.

Our expenses related to clinical trials are based on estimates of patient enrollment and related expenses at clinical investigator sites as well as estimates for the services provided and efforts expended pursuant to contracts with contract research organizations that may be used to conduct and manage our clinical trials. We recognize costs for contract manufacturing based on evaluation of the progress to completion of specific tasks. These estimates of the expense are based on communications with and information provided by the third-party service providers at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, we will adjust the amounts recorded accordingly. The estimates are trued up to reflect the best information available at the time of the financial statement issuance. We have not experienced any material differences between accrued or prepaid costs and actual costs incurred since inception.

We defer and capitalize non-refundable advance payments for goods or services that will be used or rendered for future research and development activities as prepaid expenses until the related goods are delivered or services are performed. We evaluate such payments for current or long-term classification based on when such services are expected to be received.

Warrants

To assess the initial classification of our warrants as either liability or equity, we apply judgment when evaluating the potential settlement options. We first assess whether the warrants are within the scope of ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of both Liabilities and Equity, or ASC 480. Under ASC 480, warrants are considered liability classified if the warrants are mandatorily redeemable, obligate us to settle the warrants or the underlying shares by paying cash or other assets, or require settlement by issuing variable number of shares.

If the warrants are not within the scope of ASC 480, they are subsequently assessed under ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company's Own Stock , or ASC 815-40. We review the terms of the warrants to determine whether they require or may require us to settle or net settle the contract for cash which would result in classification of the warrants as liabilities recorded at fair value. If the warrants do not require liability classification under ASC 815-40, and in order to conclude equity classification, we also assess whether the warrants are indexed to our common stock and meet equity classification criteria under ASC 815-40. Liability-classified warrants require fair value accounting at issuance and subsequent to initial issuance with all changes in fair value after the issuance date recorded in the consolidated statements of operations. Equity-classified warrants only require fair value accounting at issuance and are not subsequently remeasured.

Our pre-funded and common warrants are equity-classified instruments that were recorded in additional paid-in capital at issuance and are not subject to remeasurement. We periodically evaluate changes in facts and circumstances that could impact the classification of warrants.

Recent Accounting Pronouncements Not Yet Adopted

See Note 2-Basis of Presentation and Significant Accounting Policies to our consolidated financial statements included elsewhere in this Annual Report on Form 10-K for information about recent accounting pronouncements, the timing of their adoption, and our assessment, to the extent we have made one yet, of their potential impact on our financial condition of results of operations.