UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39402 ANNEXON, INC. (Exact name of Registrant as specified in its Charter) Delaware 27-5414423 (State or other jurisdiction of incorp ...

Exhibit 99.1 Annexon Reports Fourth Quarter and Year-End 2023 Financial Results and Key Anticipated Milestones Pivotal Phase 3 Data for ANX005 in Guillain-Barré Syndrome (GBS) Expected in Second Quarter 2024 Initiation of Pivotal Phase 3 ANX007 ARCHER II Trial in Geographic Atrophy (GA) Expected in mid-2024, a Global ShamControlled Trial Using Vision Preservation as Primary Outcome Measure Clinical Proof-of-Concept Data with ANX1502 Oral Inhibitor of the Classical Pathway Expected in Second Half of 2024 Rob ...

BRISBANE, Calif., March 18, 2024 (GLOBE NEWSWIRE) -- Annexon, Inc. (NASDAQ:ANNX), a clinical-stage biopharmaceutical company developing a new class of complement-based medicines for people living with devastating inflammatory-related diseases, today announced that it has granted inducement to a new non-executive employee under the terms of the 2022 Employment Inducement Award Plan. The equity award was approved on March 15, 2024, in accordance with Nasdaq Listing Rule 5635(c)(4). The new non-executive emplo ...

Investors are always looking for stocks that are poised to beat at earnings season and Annexon, Inc. (ANNX) may be one such company. The firm has earnings coming up pretty soon, and events are shaping up quite nicely for their report.That is because Annexon is seeing favorable earnings estimate revision activity as of late, which is generally a precursor to an earnings beat. After all, analysts raising estimates right before earnings — with the most up-to-date information possible — is a pretty good indicat ...

Annexon, Inc. (ANNX) , a clinical-stage company, is focused on developing novel therapies to treat patients suffering from serious complement-mediated autoimmune, neurodegenerative and ophthalmic disorders.The company has channeled its resources to prioritize the development of three candidates in its pipeline, such as ANX005 for Guillain-Barré syndrome, ANX007 for geographic atrophy (GA) and first-in-kind oral complement small molecule, and ANX1502 for several autoimmune indications.Over the past three mon ...

ANX005 Phase 3 Pivotal Data in Guillain-Barré Syndrome (GBS) On Track for First Half of 2024;Potential to be First Approved Treatment for GBS Patients in the U.S. ANX007 Global Pivotal Program in Geographic Atrophy (GA) to Initiate Mid-2024; First Pivotal Trial Using Vision Preservation as Primary Outcome Measure in GA Clinical Proof-of-Concept Study of ANX1502 First-in-Kind Oral Small Molecule Inhibitor of the Classical Pathway to Initiate in First Half of 2024 Recent Successful $125 Million Financing Exte ...

BRISBANE, Calif., Dec. 20, 2023 (GLOBE NEWSWIRE) -- Annexon, Inc. (NASDAQ:ANNX), a clinical-stage biopharmaceutical company developing a new class of complement medicines for patients with classical complement-mediated autoimmune, neurodegenerative and ophthalmic disorders, today announced the pricing of an underwritten public offering of 25,035,000 shares of its common stock and pre-funded warrants to purchase 18,379,861 shares of common stock. The shares of common stock are being sold at a price of $2.88 ...

Target Levels of Active Drug Achieved in Healthy Volunteers with Oral Twice-Daily Dosing; Supportive Impact on Pharmacodynamic Biomarker of Complement Activity ANX1502 Generally Well Tolerated Across Cohorts with No Serious Adverse Events Tablet Formulation of ANX1502 Expected to Advance into Proof-of-Concept Study in Patients with Cold Agglutinin Disease (CAD) in 2024 BRISBANE, Calif., Dec. 20, 2023 (GLOBE NEWSWIRE) -- Annexon, Inc. (NASDAQ:ANNX), a clinical-stage biopharmaceutical company developing a ne ...

[PART I—FINANCIAL INFORMATION](index=3&type=section&id=PART%20I%E2%80%94FINANCIAL%20INFORMATION) This section details Annexon, Inc.'s unaudited condensed consolidated financial statements and management's financial analysis [Item 1. Financial Statements](index=4&type=section&id=Item%201.%20Financial%20Statements) Annexon, Inc.'s unaudited financial statements as of September 30, 2023, report a net loss of **$32.5 million** for Q3 and **$106.3 million** for nine months, with assets at **$203.8 million** [Condensed Consolidated Balance Sheets](index=4&type=section&id=Condensed%20Consolidated%20Balance%20Sheets) Total assets decreased to **$203.8 million** as of September 30, 2023, from **$285.1 million** at year-end 2022, primarily due to reduced cash and investments Condensed Consolidated Balance Sheet Data (in thousands) | Account | September 30, 2023 (Unaudited) | December 31, 2022 | | :--- | :--- | :--- | | **Assets** | | | | Cash and cash equivalents | $133,159 | $140,020 | | Short-term investments | $32,112 | $102,637 | | Total current assets | $169,169 | $248,098 | | **Total assets** | **$203,816** | **$285,096** | | **Liabilities & Stockholders' Equity** | | | | Total current liabilities | $17,170 | $22,360 | | Total liabilities | $46,977 | $53,902 | | Accumulated deficit | $(544,608) | $(438,262) | | **Total stockholders' equity** | **$156,839** | **$231,194** | [Condensed Consolidated Statements of Operations](index=5&type=section&id=Condensed%20Consolidated%20Statements%20of%20Operations) Net loss for Q3 2023 was **$32.5 million**, and **$106.3 million** for the nine months, with operating expenses remaining stable quarterly but increasing year-to-date Condensed Consolidated Statements of Operations (in thousands) | Metric | Three Months Ended Sep 30, 2023 | Three Months Ended Sep 30, 2022 | Nine Months Ended Sep 30, 2023 | Nine Months Ended Sep 30, 2022 | | :--- | :--- | :--- | :--- | :--- | | Research and development | $27,893 | $27,862 | $90,489 | $83,966 | | General and administrative | $6,888 | $8,207 | $23,225 | $24,938 | | **Total operating expenses** | **$34,781** | **$36,069** | **$113,714** | **$108,904** | | Loss from operations | $(34,781) | $(36,069) | $(113,714) | $(108,904) | | **Net loss** | **$(32,482)** | **$(35,054)** | **$(106,346)** | **$(107,564)** | | Net loss per share | $(0.43) | $(0.51) | $(1.42) | $(2.21) | [Condensed Consolidated Statements of Cash Flows](index=9&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows) Net cash used in operating activities was **$97.7 million** for the nine months ended September 30, 2023, offset by **$72.9 million** from investing and **$17.9 million** from financing activities Cash Flow Summary for Nine Months Ended September 30 (in thousands) | Activity | 2023 | 2022 | | :--- | :--- | :--- | | Net cash used in operating activities | $(97,665) | $(89,170) | | Net cash provided by investing activities | $72,886 | $102,058 | | Net cash provided by financing activities | $17,926 | $122,800 | | **(Decrease) increase in cash, cash equivalents and restricted cash** | **$(6,853)** | **$135,688** | [Notes to Condensed Consolidated Financial Statements](index=10&type=section&id=Notes%20to%20Condensed%20Consolidated%20Financial%20Statements) Notes detail the company's clinical-stage biopharmaceutical operations, liquidity, accounting policies, and an accumulated deficit of **$544.6 million** as of September 30, 2023 - The company has experienced losses since inception, with an accumulated deficit of **$544.6 million** as of September 30, 2023[27](index=27&type=chunk) - Management projects that existing cash, cash equivalents, and short-term investments of **$165.3 million** will fund operating expenses and capital expenditure requirements for at least twelve months from the issuance date of the financial statements[27](index=27&type=chunk)[28](index=28&type=chunk) - In July 2022, the company raised net proceeds of **$122.5 million** through a private placement of common stock, pre-funded warrants, and common warrants[54](index=54&type=chunk) - During the first quarter of 2023, the company sold **2,646,458 shares** of common stock under its 2021 ATM program, generating net proceeds of approximately **$17.5 million**[56](index=56&type=chunk)[57](index=57&type=chunk) [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=19&type=section&id=Item%202.%20Management%27s%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses the company's focus on developing complement medicines, with key programs like ANX005 and ANX007, and details financial results including increased R&D expenses and liquidity projections [Overview](index=19&type=section&id=Overview) Annexon is a clinical-stage biopharmaceutical company focused on C1q-targeting complement medicines, advancing pipeline programs like ANX005, ANX007, and ANX1502 - The company is focused on stopping the classical complement pathway by targeting C1q to treat inflammatory-related diseases[79](index=79&type=chunk) - Key Pipeline Updates: - **ANX005 (GBS):** Phase 3 trial has achieved target enrollment, with data anticipated in the first half of 2024 - **ANX007 (GA):** Showed statistically significant protection from vision loss in a Phase 2 trial; regulatory interactions for Phase 3 are ongoing, with an update expected by year-end 2023; EMA granted PRIME designation - **ANX1502 (Autoimmune):** Phase 1 trial results in healthy volunteers are expected by year-end 2023[80](index=80&type=chunk)[81](index=81&type=chunk) [Results of Operations](index=22&type=section&id=Results%20of%20Operations) Q3 2023 R&D expenses were flat at **$27.9 million**, while nine-month R&D increased **8%** to **$90.5 million** due to ANX005 manufacturing costs Comparison of Operating Expenses for the Three Months Ended September 30 (in thousands) | Expense Category | 2023 | 2022 | Dollar Change | | :--- | :--- | :--- | :--- | | Research and development | $27,893 | $27,862 | $31 | | General and administrative | $6,888 | $8,207 | $(1,319) | Comparison of Operating Expenses for the Nine Months Ended September 30 (in thousands) | Expense Category | 2023 | 2022 | Dollar Change | % Change | | :--- | :--- | :--- | :--- | :--- | | Research and development | $90,489 | $83,966 | $6,523 | 8% | | General and administrative | $23,225 | $24,938 | $(1,713) | (7%) | - The **8%** increase in R&D expenses for the nine-month period was mainly driven by a **$6.6 million** increase in contract manufacturing for the pivotal stage of ANX005 development, partially offset by a **$6.2 million** decrease in clinical outside services costs due to the completion of the ARCHER trial in GA[98](index=98&type=chunk) [Liquidity and Capital Resources](index=25&type=section&id=Liquidity%20and%20Capital%20Resources) As of September 30, 2023, Annexon had **$165.3 million** in cash and investments, projected to fund operations into Q2 2025, with **$82.0 million** available via ATM program - The company's existing cash, cash equivalents, and short-term investments of **$165.3 million** are expected to fund operations into the second quarter of 2025[110](index=110&type=chunk) - The company has an active at-the-market (ATM) program with **$82.0 million** available for future sales of common stock as of September 30, 2023[111](index=111&type=chunk) Historical Cash Flows for Nine Months Ended September 30 (in thousands) | Cash Flow Activity | 2023 | 2022 | | :--- | :--- | :--- | | Net cash used in operating activities | $(97,665) | $(89,170) | | Net cash provided by investing activities | $72,886 | $102,058 | | Net cash provided by financing activities | $17,926 | $122,800 | [Item 4. Controls and Procedures](index=28&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded that disclosure controls and procedures were effective as of September 30, 2023, with no material changes in internal control over financial reporting - The Chief Executive Officer and Chief Financial Officer concluded that as of the end of the period, the company's disclosure controls and procedures are effective[119](index=119&type=chunk) - No changes in internal control over financial reporting occurred during the quarter ended September 30, 2023, that have materially affected, or are reasonably likely to materially affect, internal controls[120](index=120&type=chunk) [PART II—OTHER INFORMATION](index=29&type=section&id=PART%20II%E2%80%94OTHER%20INFORMATION) This section outlines legal proceedings, significant risk factors, and other material information impacting the company [Item 1. Legal Proceedings](index=29&type=section&id=Item%201.%20Legal%20Proceedings) The company is not currently a party to any material legal proceedings, though it may face ordinary course litigation - As of the filing date, Annexon is not party to any material legal proceedings[121](index=121&type=chunk) [Item 1A. Risk Factors](index=29&type=section&id=Item%201A.%20Risk%20Factors) The company faces significant risks including limited operating history, substantial losses, need for financing, and dependence on early-stage product development and regulatory approvals - The company is a clinical-stage biopharmaceutical company with a limited operating history, significant losses since inception, and anticipates continued losses[123](index=123&type=chunk) - Substantial additional financing is required to achieve goals, and failure to obtain it could force delays or termination of development programs[123](index=123&type=chunk) - The business is heavily dependent on the successful development, regulatory approval, and commercialization of its early-stage clinical product candidates[123](index=123&type=chunk) - The company relies on third-party suppliers for manufacturing and faces risks if these suppliers fail to comply with regulations or provide sufficient quantities[123](index=123&type=chunk) [Risks Related to Our Limited Operating History, Financial Condition and Capital Requirements](index=30&type=section&id=Risks%20Related%20to%20Our%20Limited%20Operating%20History%2C%20Financial%20Condition%20and%20Capital%20Requirements) The company has a limited operating history, significant accumulated deficit of **$544.6 million**, and requires substantial additional financing to fund operations into Q2 2025 - The company has incurred significant operating losses since inception, with a net loss of **$106.3 million** for the nine months ended September 30, 2023, and an accumulated deficit of **$544.6 million**[127](index=127&type=chunk) - The company will require substantial additional financing, and its current capital of **$165.3 million** is expected to fund operations only into the second quarter of 2025; failure to raise more capital could force delays or termination of product development[128](index=128&type=chunk)[129](index=129&type=chunk) [Risks Related to Our Business](index=33&type=section&id=Risks%20Related%20to%20Our%20Business) Business success depends on developing and commercializing early-stage product candidates, facing risks from clinical trial delays, patient enrollment, adverse effects, and reliance on third-party manufacturers - The company's business is heavily dependent on the successful development and regulatory approval of its product candidates, which are in early stages of clinical development and based on a novel therapeutic approach (C1q inhibition)[140](index=140&type=chunk)[141](index=141&type=chunk) - Clinical trials may face substantial delays or failures due to issues with generating preclinical data, regulatory disagreements, patient recruitment, or unforeseen safety events[155](index=155&type=chunk) - The company relies completely on third-party contract manufacturers for its product supply and does not have its own manufacturing capabilities, making it vulnerable to supply disruptions and compliance failures[200](index=200&type=chunk) [Risks Related to Intellectual Property](index=52&type=section&id=Risks%20Related%20to%20Intellectual%20Property) Commercial success depends on intellectual property protection, facing risks of infringement claims, patent invalidation, and breaches of trade secret confidentiality agreements - The company may face allegations of infringing third-party patent rights, which could lead to costly litigation, substantial damages, and limitations on its ability to commercialize products[242](index=242&type=chunk)[243](index=243&type=chunk) - The company's ability to compete depends on maintaining its intellectual property; patents may not issue, or issued patents may be challenged, invalidated, or circumvented[248](index=248&type=chunk)[249](index=249&type=chunk) - The company relies on confidentiality agreements to protect trade secrets, but these may be breached, and it may not have adequate remedies, potentially impairing its competitive position[262](index=262&type=chunk) [Risks Related to Government Regulation](index=59&type=section&id=Risks%20Related%20to%20Government%20Regulation) Approved products face extensive ongoing regulatory scrutiny, potential penalties for non-compliance, and challenges from healthcare legislation and fraud and abuse laws impacting pricing and reimbursement - Approved products will remain subject to extensive ongoing regulatory requirements for manufacturing (cGMP), labeling, and promotion, with potential for penalties or withdrawal of approval for non-compliance[279](index=279&type=chunk)[280](index=280&type=chunk)[282](index=282&type=chunk) - Enacted and future healthcare legislation, including the ACA and the Inflation Reduction Act (IRA), may increase the difficulty and cost of obtaining marketing approval and could negatively affect product pricing and reimbursement[285](index=285&type=chunk)[289](index=289&type=chunk) - Business operations and relationships with healthcare professionals and third-party payors are subject to fraud and abuse laws (e.g., the Anti-Kickback Statute), which could lead to significant penalties if violations are found[299](index=299&type=chunk)[300](index=300&type=chunk) [Risks Related to Our Common Stock](index=63&type=section&id=Risks%20Related%20to%20Our%20Common%20Stock) The company's common stock price is volatile, influenced by reduced disclosure as a smaller reporting company, significant insider ownership, potential future dilution, and no dividend policy - The company's common stock price has been and could continue to be subject to substantial volatility due to clinical trial results, regulatory announcements, and broader market conditions[301](index=301&type=chunk) - As of September 30, 2023, executive officers, directors, and 5%+ stockholders beneficially owned a majority of the outstanding voting stock, enabling them to exert significant control over matters requiring stockholder approval[313](index=313&type=chunk) - The company does not intend to pay dividends, so a return on investment will depend on the appreciation of the stock price[326](index=326&type=chunk)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-39402 ANNEXON, INC. (Exact name of Registrant as specified in its Charter) Delaware 27-5414423 (State or other jurisdiction of in ...