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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 March 31, 2026

☐ 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 incorporation or organization)

     (I.R.S. Employer
Identification No.)

1400 Sierra Point Parkway, Bldg C, Suite 200

Brisbane, California 94005

(Address of principal executive offices including zip code)

Registrant’s telephone number, including area code: (650) 822-5500

Former name, former address and former fiscal year, if changed since last report: Not applicable

Securities registered pursuant to Section 12(b) of the Act:


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.001 per share	ANNX	The Nasdaq Stock Market LLC

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ NO ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ NO ☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.


Large accelerated filer	☐	Accelerated filer	☐

Non-accelerated filer	☒	Smaller reporting company	☒

		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES ☐ NO ☒

The number of shares of the Registrant’s Common Stock outstanding as of May 4, 2026 was 163,842,538. This number does not include 35,765,799 shares of Common Stock issuable upon the exercise of pre-funded warrants (which are immediately exercisable at an exercise price of $0.001 per share of Common Stock, subject to beneficial ownership limitations). See Note 6—Stockholders’ Equity to the Registrant’s unaudited condensed consolidated financial statements.

Table of Contents


		Page
	PART I—FINANCIAL INFORMATION
Item 1.	Financial Statements (Unaudited)
	Condensed Consolidated Balance Sheets	1
	Condensed Consolidated Statements of Operations	2
	Condensed Consolidated Statements of Comprehensive Loss	3
	Condensed Consolidated Statements of Stockholders’ Equity	4
	Condensed Consolidated Statements of Cash Flows	6
	Notes to Condensed Consolidated Financial Statements	7
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	17
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	24
Item 4.	Controls and Procedures	24

	PART II—OTHER INFORMATION
Item 1.	Legal Proceedings	25
Item 1A.	Risk Factors	25
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	69
Item 3.	Defaults Upon Senior Securities	69
Item 4.	Mine Safety Disclosures	69
Item 5.	Other Information	69
Item 6.	Exhibits	70
SIGNATURES		71

In this Quarterly Report on Form 10-Q, “we,” “our,” “us,” “Annexon” and the “Company” refer to Annexon, Inc. and its consolidated subsidiary. Annexon, Annexon, Inc., the Annexon logo and other trade names, trademarks or service marks of Annexon are the property of Annexon, Inc. This report contains references to our trademarks and to trademarks belonging to other entities. Trade names, trademarks and service marks of other companies appearing in this report are the property of their respective holders. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

ANNEXON, INC.

Condensed Consolidated Balance Sheets

(in thousands)


	March 31, 2026			December 31, 2025
	(Unaudited)
Assets
Current assets:
Cash and cash equivalents	$	175,208		$	162,051
Short-term investments		49,817			76,294
Prepaid expenses and other current assets		3,241			3,846
Total current assets		228,266			242,191
Restricted cash		1,032			1,032
Property and equipment, net		10,107			10,617
Operating lease right-of-use assets		14,767			15,185
Other non-current assets		8,716			8,546
Total assets	$	262,888		$	277,571
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	17,529		$	14,931
Accrued and other current liabilities		15,392			24,791
Operating lease liabilities, current		3,016			2,908
Total current liabilities		35,937			42,630
Operating lease liabilities, non-current		22,418			23,293
Total liabilities		58,355			65,923
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock		162			149
Additional paid-in capital		1,165,983			1,128,917
Accumulated other comprehensive loss		(81	)		(29	)
Accumulated deficit		(961,531	)		(917,389	)
Total stockholders’ equity		204,533			211,648
Total liabilities and stockholders’ equity	$	262,888		$	277,571

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Condensed Consolidated Statements of Operations

(in thousands, except share and per share amounts)

(Unaudited)


	Three Months Ended March 31,
	2026			2025
Operating expenses:
Research and development	$	35,786		$	48,179
General and administrative		10,267			9,226
Total operating expenses		46,053			57,405
Loss from operations		(46,053	)		(57,405	)
Interest and other income, net		1,911			3,049
Net loss	$	(44,142	)	$	(54,356	)
Net loss per share, basic and diluted	$	(0.23	)	$	(0.37	)
Weighted-average shares used in computing net loss per share, basic and diluted		194,200,100			148,108,809

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Condensed Consolidated Statements of Comprehensive Loss

(in thousands)

(Unaudited)


	Three Months Ended March 31,
	2026			2025
Net loss	$	(44,142	)	$	(54,356	)
Other comprehensive income (loss):
Foreign currency translation adjustment		1			—
Unrealized loss on available-for-sale securities		(53	)		(101	)
Comprehensive loss	$	(44,194	)	$	(54,457	)

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Condensed Consolidated Statements of Stockholders’ Equity

(in thousands, except share amounts)

(Unaudited)


	Common Stock				Additional Paid-In			Accumulated Other Comprehensive			Accumulated			Total Stockholders’
	Shares		Cost		Capital			Loss			Deficit			Equity
Balances as of December 31, 2025		149,362,800	$	149	$	1,128,917		$	(29	)	$	(917,389	)	$	211,648
Exercise of stock options		61,306		—		229			—			—			229
Restricted stock vested in the period		501,341		—		—			—			—			—
Issuance of common stock, net of issuance costs $909		6,049,762		6		32,688			—			—			32,694
Exercise of pre-funded warrants		6,526,508		7		(7	)		—			—			—
Stock-based compensation		—		—		4,156			—			—			4,156
Other comprehensive loss		—		—		—			(52	)		—			(52	)
Net loss		—		—		—			—			(44,142	)		(44,142	)
Balances as of March 31, 2026		162,501,717	$	162	$	1,165,983		$	(81	)	$	(961,531	)	$	204,533

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Condensed Consolidated Statements of Stockholders’ Equity

(in thousands, except share amounts)

(Unaudited)


	Common Stock				Additional Paid-In		Accumulated Other Comprehensive			Accumulated			Total Stockholders’
	Shares		Cost		Capital		Income (Loss)			Deficit			Equity
Balances as of December 31, 2024		109,381,556	$	109	$	1,003,685	$	10		$	(710,699	)	$	293,105
Exercise of stock options		43,113		—		62		—			—			62
Restricted stock vested in the period		289,735		—		—		—			—			—
Stock-based compensation		—		—		5,078		—			—			5,078
Other comprehensive loss		—		—		—		(101	)		—			(101	)
Net loss		—		—		—		—			(54,356	)		(54,356	)
Balances as of March 31, 2025		109,714,404	$	109	$	1,008,825	$	(91	)	$	(765,055	)	$	243,788

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Condensed Consolidated Statements of Cash Flows

(in thousands)

(Unaudited)


	Three Months Ended March 31,
	2026			2025
Operating activities:
Net loss	$	(44,142	)	$	(54,356	)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization		539			537
Accretion of discount on available-for-sale securities		(632	)		(1,850	)
Stock-based compensation		4,156			5,078
Reduction in the carrying amount of right-of-use assets		418			359
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		605			(22	)
Other non-current assets		275			(2,032	)
Accounts payable		2,151			(31	)
Accrued and other current liabilities		(9,399	)		2,926
Operating lease liabilities		(767	)		(664	)
Net cash used in operating activities		(46,796	)		(50,055	)
Investing activities:
Purchases of property and equipment		—			(74	)
Purchases of available-for-sale securities		(5,944	)		(61,806	)
Proceeds from maturities of available-for-sale securities		33,000			159,500
Net cash provided by investing activities		27,056			97,620
Financing activities:
Proceeds from the exercise of common stock options		229			62
Proceeds from the issuance of common stock		33,603			—
Payment of financing costs		(936	)		(3	)
Net cash provided by financing activities		32,896			59
Increase in cash, cash equivalents and restricted cash		13,156			47,624
Effect of exchange rate changes on cash, cash equivalents and restricted cash		1			—
Cash, cash equivalents and restricted cash
Beginning of period		163,083			50,530
End of period	$	176,240		$	98,154
Supplemental disclosure of cash flow information:
Cash paid for amounts included in the measurement of lease liability	$	1,303		$	1,259
Non-cash investing and financing activities:
Deferred offering costs included in accounts payable and accrued liabilities	$	423		$	30
Deferred offering costs included in other non-current assets	$	445		$	81

See accompanying notes to unaudited condensed consolidated financial statements.

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

1. Organization

Annexon, Inc., or the Company, is a biopharmaceutical company advancing the next generation platform of targeted immunotherapies aimed at complement-mediated neuroinflammatory diseases that impact nearly 10 million people worldwide. The Company is located in Brisbane, California and was incorporated in Delaware in March 2011.

The Company’s wholly-owned subsidiary, Annexon Biosciences Australia Pty Ltd, or the Subsidiary, is a proprietary limited company incorporated in 2016 and domiciled in Australia.

Liquidity

Since inception, the Company has been involved primarily in performing research and development activities, conducting clinical trials, hiring personnel, and raising capital to support and expand these activities. The Company has experienced losses and negative cash flows from operations since its inception and, as of March 31, 2026, had an accumulated deficit of $961.5 million and cash and cash equivalents and short-term investments of $225.0 million.

The Company has historically funded its operations through the issuance of shares of its common stock and warrants. Based on projected activities, management projects that existing cash and cash equivalents and short-term investments will enable the Company to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these financial statements. The Company’s future viability beyond that point is dependent on its ability to achieve development and regulatory milestones and obtain additional funding. Management expects to continue to incur losses and negative cash flows from operations for at least the next several years. There are uncertainties associated with the Company’s ability to (1) obtain additional equity or debt financing on terms that are favorable to the Company, (2) enter into collaborative agreements with strategic partners, and (3) succeed in its future operations. If the Company is not able to obtain the required funding for its operations or is not able to obtain funding on terms that are favorable to the Company, it could be forced to delay, reduce or eliminate its research and development programs and its business could be materially harmed.

2. Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP, and applicable rules and regulations of the SEC regarding interim financial reporting.

The condensed consolidated balance sheet as of March 31, 2026, the condensed consolidated statements of operations, comprehensive loss, stockholders’ equity for the three months ended March 31, 2026 and 2025 and the condensed consolidated statements of cash flows for the three months ended March 31, 2026 and 2025 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position, results of operations and cash flows for the interim period presented. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three month periods are also unaudited. The results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2025 included herein was derived from the audited consolidated financial statements as of that date. These unaudited condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 30, 2026.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported expenses during the reporting period. Management evaluates its estimates, including but not limited to the fair value of investments, incremental borrowing rate for operating lease right-of-use assets and liabilities, valuation of deferred tax assets and uncertain tax positions (including valuation

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

allowance), clinical trial accruals and stock-based compensation. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.

Principles of Consolidation

The condensed consolidated financial statements include the operations of Annexon, Inc. and its wholly-owned subsidiary and include the results of operations and cash flows of these entities. All intercompany balances and transactions have been eliminated in consolidation.

Summary of Significant Accounting Policies

Reference is made to Note 2, Summary of Significant Accounting Policies, in the Company’s 2025 Form 10-K filed on March 30, 2026 for a detailed description of significant accounting policies. There have been no significant changes to the Company’s accounting policies as disclosed in its 2025 Form 10-K.

Recently Issued Accounting Pronouncements

In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures: Disaggregation of Income Statement Expenses, which requires public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. This guidance is effective for annual reporting periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270) Narrow-Scope Improvements. The ASU clarifies and reorganizes interim reporting guidance, including disclosure requirements related to events occurring since the end of the most recent annual reporting period, and improves the presentation and usability of interim financial statement disclosures. The ASU is effective for interim reporting periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

3. Fair Value Measurements

The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines fair value based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels:

•

Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date.

•

Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability.

•

Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date.

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

On a recurring basis, the Company measures certain financial assets and liabilities at fair value. The following tables summarize the fair value of the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		March 31, 2026
	Valuation Hierarchy	Amortized Cost Basis		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Aggregate Fair Value
Assets:
Cash equivalents:
Money market funds	Level 1	$	152,288	$	—	$	—	$	152,288
Government bonds	Level 2		11,961		—		—		11,961
Total cash equivalents			164,249		—		—		164,249
Short-term investments:
Government bonds	Level 2		49,816		1		—		49,817
Total short-term investments			49,816		1		—		49,817
		$	214,065	$	1	$	—	$	214,066


		December 31, 2025
	Valuation Hierarchy	Amortized Cost Basis		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Aggregate Fair Value
Assets:
Cash equivalents:
Money market funds	Level 1	$	116,181	$	—	$	—	$	116,181
Government bonds	Level 2		43,844		13		—		43,857
Total cash equivalents			160,025		13		—		160,038
Short-term investments:
Government bonds	Level 2		76,252		42		—		76,294
Total short-term investments			76,252		42		—		76,294
		$	236,277	$	55	$	—	$	236,332

All of the investments held as of March 31, 2026, had original maturities of less than two years. As of March 31, 2026, all of the investments are scheduled to mature within 12 months. During the three months ended March 31, 2026, the Company did not recognize any credit losses. The Company determined that the decline in fair value of debt securities was not due to credit-related factors, and no allowance for expected credit losses was recorded as of March 31, 2026. There were nominal unrealized losses as of March 31, 2026, and no investments have been in the loss position for more than 12 months. However, the Company is planning to hold these securities until maturity and expects to recover the amortized cost basis.

For the three months ended March 31, 2026 and 2025, the Company recognized no material realized gains or losses on financial instruments.

4. Balance Sheet Components

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid instruments with an original maturity of three months or less at time of purchase to be cash equivalents. Cash equivalents, which include amounts invested in money market funds and government bonds, are stated at fair value.

Restricted cash as of March 31, 2026 relates to the letters of credit established for the Company’s office leases.

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the unaudited condensed consolidated balance sheets that sum to the total of the same amounts shown in the unaudited condensed consolidated statements of cash flows (in thousands):


	March 31, 2026		December 31, 2025
Cash	$	10,959	$	2,013
Cash equivalents		164,249		160,038
Cash and cash equivalents		175,208		162,051
Restricted cash		1,032		1,032
Cash, cash equivalents and restricted cash	$	176,240	$	163,083

Property and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):


	March 31, 2026			December 31, 2025
Leasehold improvements	$	17,254		$	17,262
Laboratory equipment		1,878			1,878
Furniture and fixtures		730			730
Computer equipment and software		92			92
Construction in progress		37			—
Total property and equipment, gross		19,991			19,962
Less: accumulated depreciation		(9,884	)		(9,345	)
Total property and equipment, net	$	10,107		$	10,617

The Company recognized depreciation expense for property and equipment of $0.5 million for each of the three months ended March 31, 2026 and 2025.

Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of the following (in thousands):


	March 31, 2026		December 31, 2025
Accrued research and development expenses	$	11,014	$	16,285
Accrued compensation		2,254		7,517
Accrued professional services		1,672		480
Other accrued and current liabilities		452		509
Total accrued and other current liabilities	$	15,392	$	24,791

5. Commitments and Contingencies

Leases

The Company leases its offices and laboratory in Brisbane, California, under a ten-year noncancelable lease agreement that ends in October 2031 with a ten-year renewable option.

As of March 31, 2026, the operating lease right-of-use assets were $14.8 million and lease liabilities were $25.4 million on the unaudited condensed consolidated balance sheet. The weighted-average remaining lease term is 5.6 years.

The weighted-average incremental borrowing rate used to measure the operating lease liability is 8.4%.

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

Operating lease costs were $1.0 million for each of the three months ended March 31, 2026 and 2025. Variable lease payments were $0.6 million and $0.7 million for the three months ended March 31, 2026 and 2025, respectively.

Future minimum lease payments and related lease liabilities as of March 31, 2026, were as follows:


	(in thousands)
2026 (remaining nine months)	$	3,939
2027		5,425
2028		5,615
2029		5,812
2030 and thereafter		11,173
Total undiscounted lease payments		31,964
Less: Imputed interest		(6,530	)
Total lease liabilities	$	25,434

Guarantees and Indemnifications

In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. As of March 31, 2026, the Company did not have any material indemnification claims that were probable or reasonably possible and consequently has not recorded related liabilities.

6. Stockholders’ Equity

2025 Financing

In November 2025, the Company raised net proceeds of approximately $80.5 million after deducting underwriting discounts and offering expenses through the sale of 29,423,075 shares of the Company’s 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. The pre-funded warrants are immediately exercisable, subject to certain beneficial ownership limitations. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital.

2024 Financing

In June 2024, the Company raised net proceeds of approximately $116.8 million after deducting underwriting discounts and offering expenses through the sale of 13,001,120 shares of the Company’s common stock, par value $0.001 per share, 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. The pre-funded warrants are immediately exercisable, subject to certain beneficial ownership limitations. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital. In March 2026, the Company 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.

2023 Financing

In December 2023, the Company raised net proceeds of approximately $117.0 million after deducting underwriting discounts and offering expenses through the sale of 25,035,000 shares of the Company’s common stock, par value $0.001 per share 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. An entity related to one of the Company’s directors participated in the public offering and purchased 350,000 shares of common stock for an aggregate price of approximately $1.0 million. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital. In March 2026, the Company

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

issued an aggregate of 2,027,384 shares of common stock upon the cashless exercise of pre-funded warrants to purchase 2,027,778 shares of common stock.

2022 Financing

In July 2022, the Company 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 its common stock and accompanying common warrants to purchase up to 8,427,508 shares of its 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. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital.

In June 2025, the Company and holders of common warrants exercisable for 6,877,622 shares of the Company’s 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), the Company would receive aggregate gross proceeds of approximately $39.9 million. The remaining common warrants to purchase 1,226,993 shares of the Company's common stock not subject to these amendments expired unexercised on June 30, 2025.

The Company concluded that the modified common warrants retain equity classification. The excess of fair value of the modified warrants over the fair value of the warrants immediately before the modification of $1.9 million was recognized as a deemed dividend for the year ended December 31, 2025. This modification included a related party transaction involving 613,497 common warrants held by a fund affiliated with a member of our board of directors, which accounted for $0.2 million of the deemed dividend recognized. As the Company had an accumulated deficit as of December 31, 2025, the deemed dividend was recognized in additional paid-in capital with zero net impact on stockholders' equity. There was no deemed dividend recognized during the three months ended March 31, 2026.

Pre-Funded and Common Warrants

The following summarizes warrant activity during the three months ended March 31, 2026 and 2025:


	Number of Common Warrants		Number of Pre-funded Warrants			Weighted-Average Exercise Price
Balances as of December 31, 2025		6,877,622		42,293,577
Exercised	—			(6,527,778	)	$	0.001
Balances as of March 31, 2026		6,877,622		35,765,799


	Number of Common Warrants		Number of Pre-funded Warrants		Weighted-Average Exercise Price
Balances as of December 31, 2024		8,104,615		38,543,577
Issued		—		—	$	—
Balances as of March 31, 2025		8,104,615		38,543,577

At the Market (ATM) Program

In March 2026, the Company entered into a sales agreement with TD Securities (USA) LLC, or TD Cowen, as sales agent, pursuant to which the Company may offer and sell, from time to time through TD Cowen, at its option, shares of its common stock having an aggregate offering price of up to $150.0 million, or the 2026 ATM program. The Company agreed to pay TD Cowen a commission of up to 3.0% of the aggregate gross proceeds for the common stock sold through the 2026 ATM program. During the three months ended March 31, 2026, no sales were made under the 2026 ATM program. Subsequent to March 31, 2026 and through the date of issuance of these interim unaudited condensed consolidated financial statements, the Company sold 1,305,463 shares of common stock under the 2026 ATM program for net proceeds of approximately $8.1 million, after deducting commissions paid to TD Cowen.

In March 2024, the Company entered into a sales agreement with TD Cowen, as sales agent, or 2024 ATM program, pursuant to which the Company may issue and sell shares of its common stock for an aggregate maximum offering of $100.0 million. During the

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

three months ended March 31, 2026, the Company sold 6,049,762 shares of its common stock under the 2024 ATM program for net proceeds of approximately $32.7 million, after deducting commissions paid to TD Cowen and other offering costs. Approximately $33.3 million remained available under the 2024 ATM program, which the Company terminated in May 2026.

Common Stock

The Company reserved the following shares of common stock for issuance as follows:


	March 31, 2026		December 31, 2025
Stock options issued and outstanding		22,483,361		18,645,325
Stock options reserved for 2020 Incentive Award Plan		1,441,747		1,184,877
Unvested restricted stock units outstanding		2,550,181		1,252,847
Common stock reserved for 2024 ATM program		8,459,414		14,509,176
Common stock reserved for 2026 ATM program		30,000,000		—
Common stock reserved for Employee Stock Purchase Plan		4,294,178		2,800,550
Common stock reserved for 2022 Employment Inducement Award Plan		3,605,418		3,585,793
Common stock reserved for pre-funded warrants		35,765,799		42,293,577
Common stock reserved for common warrants		6,877,622		6,877,622
Total common stock reserved		115,477,720		91,149,767

7. Equity Incentive Plans

In July 2020, the Company’s board of directors and stockholders adopted and approved the 2020 Incentive Award Plan, or the 2020 Plan, and the Employee Stock Purchase Plan, or the ESPP, which became effective in connection with the Company’s initial public offering, or the IPO.

The Company may not grant any additional awards under the 2011 Equity Incentive Plan, or the 2011 Plan. The 2011 Plan will continue to govern outstanding equity awards granted thereunder.

2020 Incentive Award Plan

The number of shares of common stock reserved for issuance under the 2020 Plan automatically increases on the first day of January, in an amount equal to 4% of the total number of shares of the Company’s capital stock outstanding on the last day of the preceding year, or a lesser number of shares determined by the Company’s board of directors.

Awards granted under the 2020 Plan expire no later than ten years from the date of grant. For Incentive Stock Options, or ISOs, and Nonstatutory Stock Options, or NSOs, the option price shall not be less than 100% of the estimated fair value on the date of grant. Options granted typically vest over a four-year period but may be granted with different vesting terms. As of March 31, 2026, there were 1,441,747 shares available for issuance under the 2020 Plan.

2022 Employment Inducement Award Plan

In July 2022, the Company’s board of directors adopted the Annexon, Inc. 2022 Employment Inducement Award Plan, as amended, or the Inducement Plan, and together with the 2011 Plan and the 2020 Plan, the Plans. The Inducement Plan was adopted by the Company’s board of directors without stockholder approval pursuant to Nasdaq Marketplace Rule 5635(c)(4), or Rule 5635(c)(4). In accordance with Rule 5635(c)(4), awards made under the Inducement Plan may only be granted to newly hired employees as an inducement material to the employees entering into employment with the Company. Awards granted under the Inducement Plan expire no later than ten years from the date of grant. An aggregate of 7,850,000 shares of common stock were reserved for issuance under the Inducement Plan. As of March 31, 2026, there were 3,605,418 shares available for issuance under the Inducement Plan.

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

Stock Options

The following table presents stock option activity under the Plans for the period:


	Number of Shares			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balances as of December 31, 2025		18,645,325		$	6.69		7.53	$	17,234
Stock options granted		4,199,313		$	5.26
Stock options exercised		(61,306	)	$	3.74
Stock options forfeited		(299,971	)	$	4.96
Balances as of March 31, 2026		22,483,361		$	6.45		7.73	$	23,698
Vested and Exercisable as of March 31, 2026		10,981,145		$	8.70		6.34	$	8,056

The total intrinsic value of options exercised was $0.1 million for each of the three months ended March 31, 2026 and 2025. The intrinsic value is the difference between the fair value of the Company’s common stock at the time of exercise and the exercise price of the stock option.

The weighted-average grant date fair value of options granted to employees during the three months ended March 31, 2026 and 2025 was $4.05 and $2.01 per share, respectively.

As of March 31, 2026, the total unrecognized stock-based compensation cost related to outstanding unvested stock options was $37.2 million, which the Company expects to recognize over an estimated weighted-average period of 3.0 years.

Restricted Stock Units

RSUs are share awards that entitle the holder to receive freely tradeable shares of the Company’s common stock upon vesting. The RSUs cannot be transferred and the awards are subject to forfeiture if the holder’s employment terminates prior to the release of the vesting restrictions. The RSUs generally vest over a three-year period in equal amounts on an annual basis, provided the employee remains continuously employed with the Company. The fair value of the RSUs is equal to the closing price of the Company’s common stock on the grant date.

A summary of RSU activity under the Company’s equity incentive plan and related information is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Unvested as of December 31, 2025		1,252,847		$	3.31
Granted		1,855,563			5.38
Vested		(501,341	)		3.69
Cancelled		(56,888	)		4.26
Unvested as of March 31, 2026		2,550,181		$	4.72

As of March 31, 2026, unrecognized stock-based compensation expense related to outstanding unvested RSUs was $11.5 million, which is expected to be recognized over a weighted-average period of 2.7 years.

Employee Stock Purchase Plan

The ESPP enables eligible employees to purchase shares of the Company’s common stock at the end of each offering period at a price equal to 85% of the fair market value of the shares on the first business day or the last business day of the offering period, whichever is lower. Eligible employees generally include all employees. Share purchases are funded through payroll deductions of at least 1%, and up to 15% of an employee’s eligible compensation for each payroll period. The number of shares reserved for issuance under the ESPP increase automatically on the first day of each fiscal year, by a number equal to, 1% of the shares of common stock outstanding on the last day of the immediately preceding fiscal year, or such number of shares determined by the Company’s board of directors. As of

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

March 31, 2026, 4,294,178 shares were available for future purchase. The ESPP generally provides for six-month consecutive offering periods beginning on May 16 and November 16 of each year. The ESPP is a compensatory plan as defined by the authoritative guidance for stock compensation. As such, stock-based compensation expense has been recorded for the three months ended March 31, 2026.

The stock-based compensation expense related to the ESPP was $47,000 and $40,000 for the three months ended March 31, 2026 and 2025, respectively.

Stock-Based Compensation Expense

The total stock-based compensation expense recognized was as follows (in thousands):


	Three Months Ended March 31,
	2026		2025
Research and development	$	2,368	$	2,829
General and administrative		1,788		2,249
Total stock-based compensation expense	$	4,156	$	5,078

To determine the value of stock option awards for stock-based compensation purposes, the Company uses the Black-Scholes option pricing model and the assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment.

Fair Value of Common Stock—The fair value of each share of underlying common stock is based on the closing price of the Company’s common stock as reported on the date of grant on the Nasdaq Global Select Market.

Expected Term—The expected term represents the period that the stock-based awards are expected to be outstanding and is determined using the simplified method. The Company continues using the simplified method as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term due to the limited period of time its equity shares have been publicly traded.

Expected Volatility—Beginning in 2026, the expected volatility assumption is estimated based solely on the historical volatility of the Company’s share trading price for its common stock and is no longer derived from a weighted average that includes comparable publicly traded life sciences companies. Prior to 2026, the expected volatility was estimated based on a weighted volatility using both the Company’s trading history for its common stock and the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on similar size, stage in life cycle, or area of specialty.

Risk-Free Interest Rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the option.

Dividend Yield—The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero.

The fair value of each stock option issued was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:


	Three Months Ended March 31,
	2026	2025
Expected term (in years)	6.02 - 6.08	5.77 - 6.08
Expected volatility	91.7% - 92.3%	92.3% - 93.8%
Risk-free interest rate	3.72% - 3.96%	4.13% - 4.49%
Dividend yield	—	—

ANNEXON, INC.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

8. Net Loss Per Share

The Company calculates basic net loss per share by dividing net loss by the weighted-average number of shares of common stock outstanding, excluding restricted common stock. The weighted-average number of shares of common stock used in the basic and diluted net loss per share calculation include pre-funded warrants to purchase up to 35,765,799 shares of common stock, as the pre-funded warrants are exercisable at any time for nominal cash consideration. The Company has generated a net loss in all periods presented, so the basic and diluted net loss per share are the same, as the inclusion of the potentially dilutive securities would be anti-dilutive.

The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect:


	Three Months Ended March 31,
	2026		2025
Stock options to purchase common stock		22,483,361		19,852,941
Shares subject to Employee Stock Purchase Plan		140,559		144,421
Unvested restricted stock units		2,550,181		1,516,623
Common warrants		6,877,622		8,104,615
Total		32,051,723		29,618,600

9. Segment Reporting

The Company has one reportable segment, which is related to the research and development of its product candidates focused on complement-mediated diseases of the body, brain and eye for which there is significant unmet medical need. The accounting policies of the one reportable segment are the same as those described in the summary of significant accounting policies. See Note 2—Basis of Presentation and Significant Accounting Policies.

The segment is managed on a consolidated basis and the chief operating decision maker, or CODM, uses total operating expenses and consolidated net loss to assess performance, forecast future financial results and allocate resources. In assessing the Company's financial performance and making strategic decisions, the CODM regularly reviews operating expenses by function. This includes a review of budget versus actual expenses and direct program spend, which includes clinical costs, consultant fees, manufacturing expenses, and other direct external costs.

The following table presents the operations for the reportable segment for the three months ended March 31, 2026 and 2025 (in thousands):


	Three Months Ended March 31,
	2026			2025
Research and development - external expenses(1)	$	23,821		$	34,498
Research and development - personnel		7,410			9,046
General and administrative - personnel		2,917			2,340
Other general and administrative expenses(2)		7,210			5,906
Depreciation expense		539			537
Stock-based compensation		4,156			5,078
Total operating expense		46,053			57,405
Loss from operations		(46,053	)		(57,405	)
Interest and other income, net		1,911			3,049
Consolidated segment net loss	$	(44,142	)	$	(54,356	)

__________________

(1) Research and development - external expenses include program expenses, other non-program specific expenses and other research expenses.

(2) Other general and administrative expenses include consulting and professional services fees for legal, accounting, tax, and facilities costs.

Item 2. 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 unaudited condensed consolidated financial statements and the related notes and other financial information included elsewhere in this Quarterly Report on Form 10-Q and our consolidated financial statements and related notes thereto for the year ended December 31, 2025, included in our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission, or the SEC, on March 30, 2026.

In addition to historical financial information, this discussion and other parts of this report contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, based upon current expectations about us and our industry that involve substantial risks and uncertainties. Our actual results could differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth in the section titled “Risk Factors” under Part II, Item 1A below. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “position,” “potential,” “predict,” “seek,” “should,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms. Forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and events to differ from those anticipated. These statements are based upon information available to us as of the date of this Quarterly Report on Form 10-Q, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements, like all statements in this report, speak only as of their date, and we undertake no obligation to update or revise these statements in light of future developments. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

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 dry age-related macular degeneration, or AMD, with 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. We continue to engage with applicable EU and U.S. regulators to advance tanruprubart towards registration worldwide. Our Marketing Authorization Application, or MAA, filed with the European Medicines Agency, or EMA, in January 2026 for tanruprubart for the treatment of GBS is under review, and we continue to engage with EU regulators through the MAA review process. Tanruprubart has been granted orphan designation from the EMA. Tanruprubart has also been granted Fast Track and orphan drug designation for the treatment of GBS from the FDA. The currently ongoing open-label U.S./Europe FORWARD study is designed to broaden Western experience with tanruprubart, and we anticipate initial pharmacokinetics, or PK, pharmacodynamics, or PD, biomarker and functional data in 2026 to supplement our comprehensive data package for tanruprubart in GBS. Following such data, we plan to engage with the FDA with the goal of reaching alignment on our current and supplemental data package and information supporting the generalizability of tanruprubart in Western patients for submission of a biologics license application, or BLA, in 2026.

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, 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 $44.1 million and $54.4 million for the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, we had an accumulated deficit of $961.5 million and cash and cash equivalents and short-term investments of $225.0 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:

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preclinical and clinical outside service costs associated with discovery, preclinical and clinical testing of our product candidates;

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professional services agreements with third party contract organizations, investigative clinical trial sites and consultants that conduct research and development activities on our behalf;

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contract manufacturing costs to produce clinical trial materials and commercial materials to support our planned regulatory package submissions to FDA and other foreign regulatory agencies; and

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laboratory supplies and materials.

Indirect expenses include:

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compensation and personnel-related expenses (including stock-based compensation);

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allocated expenses for facilities and depreciation; and

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other indirect costs.

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 vary from period to period 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 vary from period to period 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 Three Months Ended March 31, 2026 and 2025

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


	Three Months Ended March 31,
	2026			2025			Dollar Change			% Change
	(in thousands)
Operating expenses:
Research and development	$	35,786		$	48,179		$	(12,393	)		(26	%)
General and administrative		10,267			9,226			1,041			11	%
Total operating expenses		46,053			57,405			(11,352	)		(20	%)
Loss from operations		(46,053	)		(57,405	)		11,352			(20	%)
Interest and other income, net		1,911			3,049			(1,138	)		(37	%)
Net loss	$	(44,142	)	$	(54,356	)	$	10,214			(19	%)

Research and Development Expenses


	Three Months Ended March 31,
	2026		2025		Dollar Change			% Change
	(in thousands)
Direct costs:
Clinical and nonclinical outside services	$	13,971	$	10,562	$	3,409			32	%
Consulting and professional services		4,579		6,464		(1,885	)		(29	%)
Contract manufacturing		4,644		15,865		(11,221	)		(71	%)
Laboratory supplies and materials		149		322		(173	)		(54	%)
Indirect costs:
Compensation and personnel-related (including stock-based compensation)		10,383		12,747		(2,364	)		(19	%)
Facilities and depreciation		1,771		1,984		(213	)		(11	%)
Other		289		235		54			23	%
Total research and development expenses	$	35,786	$	48,179	$	(12,393	)		(26	%)

Research and development expenses decreased by $12.4 million, or 26%, for the three months ended March 31, 2026 compared to the same period in 2025. The change was primarily attributable to a decrease of $11.2 million in completed contract manufacturing activity for the tanruprubart European MAA filing as well as the vonaprument manufacturing technology transfer to a commercial-ready facility. Compensation and personnel-related expenses (including stock-based compensation) decreased by $2.4 million, reflecting lower headcount, and consulting and professional services expenses decreased by $1.9 million. In addition, direct clinical and nonclinical outside services costs increased by $3.4 million associated with the vonaprument Phase 3 ARCHER II trial in GA and the ongoing tanruprubart FORWARD study in GBS.

General and Administrative Expenses


	Three Months Ended March 31,
	2026		2025		Dollar Change			% Change
	(in thousands)
Consulting and professional services	$	4,400	$	3,200	$	1,200			38	%
Compensation and personnel-related (including stock-based compensation)		4,891		4,745		146			3	%
Facilities and depreciation		657		712		(55	)		(8	%)
Other		319		569		(250	)		(44	%)
Total general and administrative expenses	$	10,267	$	9,226	$	1,041			11	%

General and administrative expenses increased by $1.0 million, or 11%, for the three months ended March 31, 2026 compared to the same period in 2025, primarily driven by a $1.2 million increase in consulting and professional services costs for corporate affairs activity across our portfolio.

Interest and other income, net

Interest and other income, net, decreased by $1.1 million, or 37%, for the three months ended March 31, 2026 compared to the same period in 2025. 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 in November 2025, 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 March 31, 2026, we had available cash and cash equivalents and short-term investments of $225.0 million and an accumulated deficit of $961.5 million.

Historical Cash Flows


	Three Months Ended March 31,
	2026			2025
	(in thousands)
Net cash used in operating activities	$	(46,796	)	$	(50,055	)
Net cash provided by investing activities		27,056			97,620
Net cash provided by financing activities		32,896			59
Increase in cash, cash equivalents and restricted cash	$	13,156		$	47,624

Cash Flow from Operating Activities

Cash used in operating activities for the three months ended March 31, 2026 was $46.8 million, which consisted of a net loss of $44.1 million, and a net change of $7.1 million in our operating assets and liabilities, partially offset by $4.4 million in non-cash charges. The non-cash charges consisted of stock-based compensation of $4.2 million, depreciation and amortization of $0.5 million, and a reduction in the carrying amount of right-of-use assets of $0.4 million, partially offset by accretion of discount on available-for-sale securities of $0.6 million.

Cash used in operating activities for the three months ended March 31, 2025 was $50.1 million, which consisted of a net loss of $54.4 million, partially offset by $4.1 million in non-cash charges and a net change of $0.2 million in our operating assets and liabilities. The non-cash charges consisted of stock-based compensation of $5.1 million, depreciation and amortization of $0.5 million and a reduction in the carrying amount of right-of-use assets of $0.4 million, partially offset by accretion of discount on available-for-sale securities of $1.9 million.

Cash Flow from Investing Activities

Cash provided by investing activities for the three months ended March 31, 2026 was $27.1 million, which consisted of $33.0 million of proceeds from maturities of available-for-sale securities, partially offset by $5.9 million of purchases of available-for-sale securities.

Cash provided by investing activities for the three months ended March 31, 2025 was $97.6 million, which consisted of $159.5 million of proceeds from maturities of available-for-sale securities, partially offset by $61.8 million of purchases of available-for-sale securities and $0.1 million of purchases of property and equipment.

Cash Flow from Financing Activities

Cash provided by financing activities for the three months ended March 31, 2026 was $32.9 million, which consisted of $32.7 million of net proceeds from the issuance of common stock under our 2024 ATM program and $0.2 million of net proceeds from the exercise of common stock options and employee stock purchase plan purchases.

Cash provided by financing activities for the three months ended March 31, 2025 was $0.1 million, which consisted of $0.1 million of proceeds from the exercise of common stock options.

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:

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the scope, progress, results and costs of researching and developing our current product candidates or any other future product candidates we choose to pursue, and conducting preclinical studies and clinical trials;

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the timing of, and the costs involved in, obtaining feedback from regulators on our clinical trials and regulatory approvals for our lead product candidates or any future product candidates;

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the number and characteristics of any additional product candidates we develop or acquire;

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the timing and amount of any milestone, royalty and/or other payments we are required to make pursuant to our current or any future license or collaboration agreements;

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the cost of manufacturing our lead product candidates or any future product candidates and any products we successfully commercialize;

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the cost of building a sales force in anticipation of product commercialization;

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the cost of commercialization activities of our product candidates, if approved for sale, including marketing, sales and distribution costs;

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our ability to establish strategic collaborations, licensing or other arrangements and the financial terms of any such agreements, including the timing and amount of any future milestone, royalty or other payments due under any such agreement;

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any product liability or other lawsuits related to our products;

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the expenses needed to attract, hire and retain skilled personnel;

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the costs associated with operating as a public company;

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the costs involved in preparing, filing, prosecuting, maintaining, defending and enforcing our intellectual property portfolio; and

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the timing, receipt and amount of sales of any future approved products.

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.

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. In March 2026, we issued an aggregate of 2,027,384 shares of common stock upon the cashless exercise of pre-funded warrants to purchase 2,027,778 shares of common stock.

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.

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 three months ended March 31, 2026 and 2025:


	Number of Common Warrants		Number of Pre-funded Warrants			Weighted-Average Exercise Price
Balances as of December 31, 2025		6,877,622		42,293,577
Exercised	—			(6,527,778	)	$	0.001
Balances as of March 31, 2026		6,877,622		35,765,799


	Number of Common Warrants		Number of Pre-funded Warrants		Weighted-Average Exercise Price
Balances as of December 31, 2024		8,104,615		38,543,577
Issued		—		—	$	—
Balances as of March 31, 2025		8,104,615		38,543,577

At the Market (ATM) Program

In March 2026, we entered into a sales agreement with TD Securities (USA) LLC, or TD Cowen, as sales agent, 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, or the 2026 ATM program. We agreed to pay TD Cowen a commission of up to 3.0% of the aggregate gross proceeds for the common stock sold through the 2026 ATM program. During the three months ended March 31, 2026, no sales were made under the 2026 ATM program. Subsequent to March 31, 2026 and through the date of issuance of these interim unaudited condensed consolidated financial statements, we sold 1,305,463 shares of common stock under the 2026 ATM program for net proceeds of approximately $8.1 million, after deducting commissions paid to TD Cowen.

In March 2024, we entered into a sales agreement with TD Cowen, as sales agent, or 2024 ATM program, pursuant to which we could issue and sell shares of our common stock for an aggregate maximum offering of $100.0 million. During the three months ended March 31, 2026, we sold 6,049,762 shares of our common stock under the 2024 ATM program for net proceeds of approximately $32.7

million, after deducting commissions paid to TD Cowen and other offering costs. Approximately $33.3 million remained available under the 2024 ATM program, which we terminated in May 2026.

Critical Accounting Policies and Estimates

Management’s discussion and analysis of our financial condition and results of operations is based on our unaudited condensed consolidated financial statements, which have been prepared in accordance with U.S. GAAP. The preparation of these unaudited condensed 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.

During the quarter ended March 31, 2026, there were no material changes to our critical accounting policies or in the methodology used for estimates from those described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in our Annual Report on Form 10-K for the year ended December 31, 2025.

Recent Accounting Pronouncements Not Yet Adopted

See Note 2—Basis of Presentation and Significant Accounting Policies to our unaudited condensed consolidated financial statements included elsewhere in this Quarterly Report on Form 10-Q 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.

Item 3. Quantitative and Qualitative Disclosures About Market Risk

Not applicable.

Item 4. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Our management, with the participation and supervision of our Chief Executive Officer and our Chief Financial Officer, have evaluated our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of the end of the period covered by this Quarterly Report on Form 10-Q. Based on that evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that, as of the end of the period covered by this Quarterly Report on Form 10-Q, our disclosure controls and procedures are effective to provide reasonable assurance that information we are required to disclose in reports that we file or submit under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in SEC rules and forms, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure.

Changes in Internal Control over Financial Reporting

There has been no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the quarter ended March 31, 2026 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

PART II – OTHER INFORMATION

Item 1. Legal Proceedings.

We are not party to any material legal proceedings at this time. From time to time, we may become involved in various legal proceedings that arise in the ordinary course of our business.

Item 1A. Risk Factors.

RISK FACTORS

Our business involves significant risks, some of which are described below. You should carefully consider the risks and uncertainties described below, together with all of the other information contained in this Quarterly Report on Form 10-Q, including "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the financial statements and the related notes. If any of the following risks actually occur, it could harm our business, prospects, results of operations and financial condition and future prospects. In such event, the market price of our common stock could decline and you could lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also impair our business operations. This Quarterly Report on Form 10-Q also contains forward-looking statements that involve risks and uncertainties. Our actual results could differ materially from those anticipated in the forward-looking statements as a result of factors that are described below and elsewhere in this Quarterly Report on Form 10-Q.

Risk Factor Summary

The following summarizes the most material risks that make an investment in our securities risky or speculative. If any of the following risks occur or persist, our business, financial condition and results of operations could be materially harmed and the price of our common stock could significantly decline.

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We are a clinical-stage biopharmaceutical company with a limited operating history and no products approved for commercial sale. We have incurred significant losses since our inception, and we anticipate that we will continue to incur significant losses for the foreseeable future, which, together with our limited operating history, makes it difficult to assess our future viability.

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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.

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Our business is heavily dependent on the successful development, regulatory approval and commercialization of our product candidates, some of which are in early stages of clinical development.

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Research and development of biopharmaceutical products is inherently risky. We cannot give any assurance that any of our product candidates will receive regulatory approval, which is necessary before they can be commercialized.

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We may encounter substantial delays in our clinical trials or may not be able to conduct or complete our clinical trials on the timelines we expect.

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We conduct, and in the future plan to conduct, clinical trials for product candidates outside the United States, and the Food and Drug Administration, or FDA, and comparable foreign regulatory authorities may not accept data from such trials.

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Adverse events or undesirable side effects caused by, or other unexpected properties of, any of our product candidates could halt their clinical development, delay or prevent their regulatory approval, limit their commercial potential or result in significant negative consequences.

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We rely on third-party suppliers to manufacture our product candidates, and we intend to rely on third parties to produce commercial supplies of any approved product. The loss of these suppliers, or their failure to comply with applicable regulatory requirements or to provide us with sufficient quantities at acceptable quality levels or prices, or at all, would materially and adversely affect our business.

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The successful commercialization of our product candidates will depend in part on the extent to which governmental authorities and health insurers establish adequate coverage, reimbursement levels and pricing policies. Failure to obtain or maintain coverage and adequate reimbursement for our product candidates, if approved, could limit our ability to market those products and decrease our ability to generate revenue.

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Any collaboration arrangements that we may enter into in the future may not be successful, which could adversely affect our ability to develop and commercialize our product candidates.

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If we are unable to obtain, maintain and enforce intellectual property protection directed to our current and any future technologies that we develop, others may be able to make, use or sell products substantially the same as ours, which could adversely affect our ability to compete in the market.

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Our stock price has been volatile, and could in the future be volatile, and you may not be able to resell shares of our common stock at or above the price you paid.

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Actual or perceived failure to comply with applicable data protection laws, regulations, standards, contractual obligations and other requirements related to data privacy and security could lead to government enforcement actions as well as civil and criminal penalties, private litigation (including class actions), or adverse publicity and otherwise could negatively affect our results of operations and business.

Risks Related to Our Limited Operating History, Financial Condition and Capital Requirements

We are a clinical-stage biopharmaceutical company, and we have only a limited operating history upon which you can evaluate our business and prospects. Biopharmaceutical product development is a highly speculative undertaking and involves a substantial degree of risk. We have no products approved for commercial sale and have not generated any revenue from sales of our product candidates and have incurred losses in each year since our inception in March 2011. We have only a limited operating history upon which you can evaluate our business and prospects. In addition, we have not yet demonstrated an ability to successfully overcome many of the risks and uncertainties frequently encountered by companies in new and rapidly evolving fields, particularly in the pharmaceutical, biopharmaceutical and biotechnology industry.

We have had significant operating losses since our inception. Our net loss for the years ended December 31, 2025 and 2024 was approximately $206.7 million and $138.2 million, respectively, and our net loss for the three months ended March 31, 2026 was approximately $44.1 million. As of March 31, 2026, we had an accumulated deficit of $961.5 million. Substantially all of our losses have resulted from expenses incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur losses for the foreseeable future, and we anticipate these losses will continue as we develop our product candidates, conduct clinical trials and pursue research and development activities. Even if we achieve profitability in the future, we may not be able to sustain profitability in subsequent periods. Our prior losses, combined with expected future losses, have had and will continue to have an adverse effect on our stockholders’ equity and working capital.

Since our inception, we have invested a significant portion of our efforts and financial resources in research and development activities. Our product candidates will require additional clinical development, and we intend to conduct additional research and development activities to discover and develop new product candidates, including conducting preclinical studies and clinical trials, all of which will require substantial additional funds. We will continue to expend significant resources for the foreseeable future in connection with these activities. These expenditures will include costs associated with conducting preclinical studies and clinical trials, obtaining regulatory approvals and manufacturing and supply, as well as marketing and selling any products approved for sale. In addition, other unanticipated costs may arise. Because the outcome of any preclinical study or clinical trial is highly uncertain, we cannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of our product candidates or any future product candidates.

As of March 31, 2026, we had capital resources consisting of cash and cash equivalents and short-term investments of approximately $225.0 million. We expect our existing capital resources to fund planned operating expenses into the second half of 2027. However, our operating plans may change as a result of many factors currently unknown to us, and we may need to seek additional funds sooner than planned through public or private equity offerings or debt financings or other sources, such as strategic collaborations. 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. Such financing may result in dilution to our stockholders, imposition of burdensome debt covenants and repayment obligations, or other restrictions that may affect our business. In addition, we may seek additional capital due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans.

Our future capital requirements depend on many factors, including:

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the scope, progress, results and costs of researching and developing our current product candidates or any other future product candidates we choose to pursue, conducting preclinical studies and clinical trials;

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the timing of, and the costs involved in, obtaining feedback from regulators on our clinical trials and regulatory approvals for our product candidates or any future product candidates;

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the number and characteristics of any additional product candidates we develop or acquire;

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the timing and amount of any milestone, royalty and/or other payments we are required to make pursuant to our current or any future license or collaboration agreements;

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the cost of manufacturing our product candidates or any future product candidates and any products we successfully commercialize;

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the cost of building a sales force in anticipation of product commercialization;

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the cost of commercialization activities of our product candidates, if approved for sale, including marketing, sales and distribution costs;

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any product liability or other lawsuits related to our products;

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the expenses needed to attract, hire and retain skilled personnel;

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the costs associated with operating as a public company;

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the costs involved in preparing, filing, prosecuting, maintaining, defending and enforcing our intellectual property portfolio; and

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the timing, receipt and amount of sales of any future approved products.

Additional funds may not be available when we need them, on terms that are acceptable to us, or at all. Our ability to raise additional capital may be adversely impacted by potential worsening global economic conditions, macroeconomic factors, including recent and potential bank failures, increasing inflation and interest rates, funding shortages at governmental and regulatory agencies on which we rely, exchange rate fluctuations and supply chain disruptions, geopolitical conflicts, such as the war in Ukraine and hostilities in the Middle East, and disruptions to and volatility in the credit and financial markets in the United States and worldwide. If adequate funds are not available to us on a timely basis, we may be required to:

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delay, limit, reduce or terminate preclinical studies, clinical trials or other development activities for our product candidates or any future product candidate;

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delay, limit, reduce or terminate our research and development activities; or

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delay, limit, reduce or terminate our efforts to establish manufacturing and sales and marketing capabilities or other activities that may be necessary to commercialize our product candidates or any future product candidate or reduce our flexibility in developing or maintaining our sales and marketing strategy.

We also could be required to seek funds through arrangements with collaborators or others that may require us to relinquish rights to some of our technologies or product candidates that we would otherwise pursue on our own. We do not expect to realize revenue from sales of products or royalties from licensed products in the foreseeable future, if at all, and unless and until our product candidates are clinically tested, approved for commercialization and successfully marketed. To date, we have primarily financed our operations through the sale of equity securities and warrants to purchase our equity securities. For example, in March 2026, we entered into a sales agreement (as amended from time to time), or Sales Agreement, with TD Securities (USA) LLC, or TD Cowen, 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 million under an at-the-market offering program. We will be required to seek additional funding in the future 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. Our ability to raise additional funds will depend on financial, economic and other factors, many of which are beyond our control. Additional funds may not be available to us on acceptable terms or at all. If we raise additional funds by issuing equity securities including pursuant to sales under the Sales Agreement, 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.

Due to the significant resources required for the development of our product candidates, we must prioritize development of certain product candidates and/or certain disease indications. We may expend our limited resources on candidates or indications that do not yield a successful product and fail to capitalize on product candidates or indications that may be more profitable or for which there is a greater likelihood of success.

We seek to maintain a process of prioritization and resource allocation among our programs to balance time, risk and cost, due to the significant resources required for the development of our product candidates. Our resources are primarily focused on advancing tanruprubart in GBS, and vonaprument in GA. If sufficient funding is not available, we may not be able to complete our planned clinical trials, or on the timelines we currently anticipate, and we may need to redesign, reduce the scope of or terminate some of our programs.

Our decisions concerning the allocation of research, development, collaboration, management and financial resources toward particular product candidates or therapeutic areas may not lead to the development of any viable commercial product and may divert resources away from better opportunities. Similarly, any decision to delay, terminate or collaborate with third parties in respect of certain programs may subsequently also prove to be suboptimal and could cause us to miss valuable opportunities. If we make incorrect determinations regarding the viability or market potential of any of our programs or product candidates or misread trends in the pharmaceutical, biopharmaceutical or biotechnology industry, our business, financial condition and results of operations could be materially adversely affected. As a result, we may fail to capitalize on viable commercial products or profitable market opportunities, be required to forego or delay pursuit of opportunities with other product candidates or other diseases and disease pathways that may later prove to have greater commercial potential than those we choose to pursue, or relinquish valuable rights to such product candidates through collaboration, licensing or other royalty arrangements in cases in which it would have been advantageous for us to invest additional resources to retain development and commercialization rights.

Conducting a global Phase 3 program for vonaprument in patients with dry AMD with GA will be expensive and time consuming, and we may need additional capital to complete the Phase 3 clinical program and even if favorable, the FDA and comparable foreign regulatory authorities may not accept data from our Phase 3 program.

Recent regulatory engagement regarding the Phase 3 ARCHER II trial design has established a global registration path for vonaprument in the U.S. and Europe. As a result, we are conducting ARCHER II, a global sham-controlled double-masked, Phase 3 trial. The single-study program will be analyzed as two sub-studies for the U.S. in accordance with the FDA’s two-trial recommendation. There can be no assurance that the FDA and comparable regulatory authorities will accept the data from our Phase 3 program or determine that it is sufficient to support approval.

Conducting large Phase 3 trials in multiple jurisdictions is expensive and can take many years to complete, and we cannot guarantee that clinical trials will be conducted as planned or completed timely, if at all. Our timeline and costs for ARCHER II could be substantially longer and larger than we initially planned. We may need additional capital to complete the Phase 3 clinical program for vonaprument and may not be able to raise sufficient capital in a timely manner which could delay or prevent us from completing our clinical trial, prevent us from seeking FDA approval of vonaprument, if ever, and could delay or prevent commercialization of vonaprument.

Our results of operations may fluctuate significantly, which makes our future results of operations difficult to predict and could cause our results of operations to fall below expectations.

Our quarterly and annual results of operations may fluctuate significantly, which makes it difficult for us to predict our future results of operations. These fluctuations may occur due to a variety of factors, many of which are outside of our control and may be difficult to predict, including:

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the timing and cost of, and level of investment in, research, development and, if approved, commercialization activities relating to our product candidates, which may change from time to time;

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the timing and status of enrollment for our clinical trials;

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the cost of manufacturing our product candidates, as well as building out our supply chain, which may vary depending on the quantity of production and the terms of our agreements with manufacturers;

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expenditures that we may incur to acquire, develop or commercialize additional product candidates and technologies;

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timing and amount of any milestone, royalty or other payments due under any collaboration or license agreement;

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future accounting pronouncements or changes in our accounting policies;

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the timing and success or failure of preclinical studies and clinical trials for our product candidates or competing product candidates, or any other change in the competitive landscape of our industry, including consolidation among our competitors or partners;

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the timing of receipt of approvals for our product candidates from regulatory authorities in the United States and internationally;

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coverage and reimbursement policies with respect to our product candidates, if approved, and potential future drugs that compete with our products; and

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the level of demand for our product candidates, if approved, which may vary significantly over time.

The cumulative effects of these factors could result in large fluctuations and unpredictability in our quarterly and annual results of operations. As a result, comparing our results of operations on a period-to-period basis may not be meaningful. Investors should not rely on our past results as an indication of our future performance.

This variability and unpredictability could also result in our failing to meet the expectations of industry or financial analysts or investors for any period. If our revenue or results of operations fall below the expectations of analysts or investors or below any forecasts we may provide to the market, or if any forecasts we provide to the market are below the expectations of analysts or investors, the price of our common stock could decline substantially. Such a stock price decline could occur even when we have met any previously publicly stated revenue or earnings guidance we may provide.

Risks Related to Our Business

Our business is heavily dependent on the successful development, regulatory approval and commercialization of our product candidates, some of which are in early stages of clinical development.

We have no products approved for sale, and some of our product candidates are in early stages of clinical development. The success of our business, including our ability to finance our company and generate revenue in the future, will primarily depend on the successful development, regulatory approval and commercialization of our product candidates and, in particular, the advancement of our current clinical-stage product candidates. However, given the stage of development of our product candidates, it may be many years, if we succeed at all, before we have demonstrated the safety, purity, potency and/or efficacy of a product candidate sufficient to warrant approval for commercialization. We cannot be certain that our product candidates will receive regulatory approval or be successfully commercialized even if we receive regulatory approval.

While inhibition of the complement pathway has been validated as a therapeutic approach, C1q inhibition is a novel therapeutic approach, which exposes us to certain risks. For example, we may discover that our product candidates do not possess certain properties required for therapeutic effectiveness, or even if found to be effective in one type of disease, they are not effective in other types of disease. In addition, given the novel nature of this therapeutic approach, designing preclinical studies and clinical trials to demonstrate the effect of the product candidates is complex and exposes us to risks, including that our biomarker-driven approach may not translate into therapeutic effectiveness.

In the future, we may also become dependent on other product candidates that we may develop or acquire. The clinical and commercial success of our product candidates and future product candidates will depend on a number of factors, including the following:

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our ability to raise any additional required capital on acceptable terms, or at all;

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our ability to complete an investigational new drug application, or IND, enable studies and successfully submit INDs or comparable applications;

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timely completion of our preclinical studies and clinical trials, which may be significantly slower or cost more than we currently anticipate and will depend substantially upon the performance of third-party contractors;

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whether we are required by the FDA, or similar foreign regulatory agencies to conduct additional clinical trials or other studies beyond those planned to support the approval and commercialization of our product candidates or any future product candidates;

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acceptance of our proposed indications and primary endpoint assessments relating to the proposed indications of our product candidates by the FDA and similar foreign regulatory authorities;

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our ability to demonstrate to the satisfaction of the FDA and similar foreign regulatory authorities the safety, efficacy and acceptable risk to benefit profile of our product candidates or any future product candidates;

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the prevalence, duration and severity of potential side effects or other safety issues experienced with our product candidates or future approved products, if any;

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the timely receipt of necessary marketing approvals from the FDA and similar foreign regulatory authorities;

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achieving and maintaining, and, where applicable, ensuring that our third-party contractors achieve and maintain compliance with our contractual obligations and with all regulatory requirements applicable to our product candidates or any future product candidates or approved products, if any;

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the ability of third parties with whom we contract to manufacture adequate clinical trial and commercial supplies of our product candidates or any future product candidates remain in good standing with regulatory agencies and develop, validate and maintain commercially viable manufacturing processes that are compliant with current good manufacturing practices, or cGMPs;

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our ability to successfully develop a commercial strategy and thereafter commercialize our product candidates or any future product candidates in the United States and internationally, if approved for marketing, reimbursement, sale and distribution in such countries and territories, whether alone or in collaboration with others;

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our ability to achieve sufficient market acceptance, coverage and adequate reimbursement from third-party payors and adequate market share and revenue for any approved products;

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the convenience of our treatment or dosing regimen;

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acceptance by physicians, payors and patients of the benefits, safety and efficacy of our product candidates or any future product candidates, if approved, including relative to alternative and competing treatments;

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the willingness of physicians, operators of clinics and patients to utilize or adopt any of our product candidates or any future product candidates, if approved;

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patient demand for our product candidates, if approved, including the willingness of patients to pay out-of-pocket for any approved products in the absence of coverage and/or adequate reimbursement from third-party payors;

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our ability to establish and enforce intellectual property rights in and to our product candidates or any future product candidates; and

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our ability to avoid third-party patent interference, intellectual property challenges or intellectual property infringement claims.

These factors, many of which are beyond our control, could cause us to experience significant delays or an inability to obtain regulatory approvals or commercialize our product candidates. Even if regulatory approvals are obtained, we may never be able to successfully commercialize any of our product candidates. Accordingly, we cannot provide assurances that we will be able to generate sufficient revenue through the sale of our product candidates or any future product candidates to continue our business or achieve profitability.

Public health crises such as pandemics or similar outbreaks have, and could in the future, materially and adversely affect our preclinical and clinical trials, business, financial condition and results of operations.

As a result of public health crises, including the COVID-19 pandemic, we have experienced, and may in the future experience, disruptions that could materially and adversely impact our clinical trials, business, financial condition and results of operations. These disruptions include but are not limited to:

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delays or difficulties in enrolling patients in our clinical trials;

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delays or difficulties in initiating or expanding clinical trials, including delays or difficulties with clinical site initiation and recruiting clinical site investigators and clinical site staff;

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increased rates of patients withdrawing from our clinical trials following enrollment as a result of health conditions;

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interruption of key clinical trial activities, such as clinical trial site data monitoring and efficacy, safety and translational data collection, processing and analyses, due to limitations on travel imposed or recommended by federal, state or local governments, employers and others or interruption of clinical trial subject visits, which may impact the collection and integrity of subject data and clinical study endpoints;

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diversion of healthcare resources away from the conduct of clinical trials, including the diversion of hospitals serving as our clinical trial sites and hospital staff supporting the conduct of our clinical trials;

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delays or disruptions in preclinical experiments and IND-enabling studies due to restrictions of on-site staff and unforeseen circumstances at contract research organizations, or CROs, and vendors;

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interruption or delays in the operations of the FDA and comparable foreign regulatory agencies;

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interruption of, or delays in receiving, supplies of our product candidates from our contract manufacturing organizations due to staffing shortages, production slowdowns or stoppages and disruptions in delivery systems;

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delays in receiving approval from local regulatory authorities to initiate our planned clinical trials;

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limitations on employee or other resources that would otherwise be focused on the conduct of our clinical trials and pre-clinical work, including because of sickness of employees or their families, the desire of employees to avoid travel or contact with large groups of people, an increased reliance on working from home, school closures or mass transit disruptions;

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changes in regulations as part of a response to pandemics or similar outbreaks, which may require us to change the ways in which our clinical trials are conducted, which may result in unexpected costs, or to discontinue such clinical trials altogether;

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delays in necessary interactions with regulators, ethics committees and other important agencies and contractors due to limitations in employee resources or forced furlough of government or contractor personnel; and

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refusal of the FDA to accept data from clinical trials in affected geographies outside the United States.

The extent to which any future outbreak may affect our clinical trials, business, financial condition, results of operations and clinical development timelines and plans will depend on factors including the duration of the outbreak, rates of infection in the locations in which we and our CROs, third-party manufacturers, regulatory authorities and other third parties with whom we do business operate, business closures or business disruptions and the effectiveness of actions taken in the United States and other countries to contain and treat the disease. Future developments in these and other areas present material uncertainty and risk with respect to our clinical trials, business, financial condition and results of operations.

Our future success is dependent on our ability to successfully develop, obtain regulatory approval for and successfully commercialize our product candidates, and we may fail to do so for many reasons, including the following:

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our product candidates may not successfully complete preclinical studies or clinical trials;

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a product candidate may be shown to have harmful side effects or other characteristics that indicate it does not meet applicable regulatory criteria;

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our competitors may develop therapeutics that render our product candidates obsolete or less attractive;

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the market for a product candidate may change so that the continued development of that product candidate is no longer reasonable or commercially attractive;

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a product candidate may not be capable of being produced in commercial quantities at an acceptable cost, or at all;

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if a product candidate obtains regulatory approval, we may be unable to establish sales and marketing capabilities, or successfully market such approved product candidate; and

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a product candidate may not be accepted as safe and effective by patients, the medical community or third-party payors.

If any of these events occur, we may be forced to abandon our development efforts for a product candidate or candidates, which would have a material adverse effect on our business and could potentially cause us to cease operations. Failure of a product candidate may occur at any stage of preclinical or clinical development, and we may never succeed in developing marketable products or generating product revenue.

We may not be successful in our efforts to further develop our current and future product candidates. We are not permitted to market or promote any of our product candidates before we receive regulatory approval from the FDA or comparable foreign regulatory authorities, and we may never receive such regulatory approval for any of our product candidates. Each of our product candidates will require significant additional clinical development, management of preclinical, clinical and manufacturing activities, regulatory approval, adequate manufacturing supply, a commercial organization and significant marketing efforts before we generate any revenue from product sales, if at all. Any clinical studies that we may conduct may not demonstrate the efficacy and safety necessary to obtain regulatory approval to market our product candidates. If the results of our ongoing or future clinical studies are inconclusive with respect to the efficacy of our product candidates, if we do not meet the clinical endpoints with statistical significance or if there are safety

concerns or adverse events associated with our product candidates, we may be prevented or delayed in obtaining marketing approval for our product candidates.

The FDA or other regulatory agencies may not agree with our clinical development plan and require that we conduct additional clinical trials to support our regulatory submissions. Regulatory agencies, including the FDA may require that we conduct more than one pivotal trial in order to gain approval.

Furthermore, clinical trials must be conducted in accordance with the laws, rules and regulations, guidelines and other requirements of the FDA, the EMA, and other applicable regulatory authorities outside of those jurisdictions and are subject to oversight by these regulatory authorities and institutional review boards, or IRBs, or ethics committees at the medical institutions where such clinical trials are conducted. Further, conducting global clinical trials, as we do for GBS and GA, may require that we coordinate among the legal requirements and guidelines of regulatory authorities across a number of jurisdictions, including the United States, the EU, and countries outside of those jurisdictions, which could require that we amend clinical trial protocols or determine not to conduct a trial in one or more jurisdictions or to run separate trials in various jurisdictions due to the inability, cost or delay in harmonizing divergent requests from such regulatory authorities, all of which could increase costs. In addition, clinical trials that are conducted in countries outside the United States and the EU may subject us to risks associated with the engagement of non-United States and non-EU CROs who are unknown to the FDA or the EMA, or the EU member states’ regulatory authorities and may have different standards of diagnosis, screening and medical care, as well as risks associated with further delays and expenses as a result of increased shipment costs (including as a result of local quality release or in-country testing of a product candidate supply produced in a different jurisdiction for our clinical trials) and political and economic risks relevant to such countries outside the United States and the EU.

If any of our product candidates successfully completes clinical trials, we plan to seek regulatory approval to market our product candidates in the United States, the EU, and in additional foreign countries where we believe there is a viable commercial opportunity. We may never receive regulatory approval to market any product candidates even if such product candidates successfully complete clinical trials, which would adversely affect our viability. To obtain regulatory approval in countries outside the United States, we must comply with numerous and varying regulatory requirements of such other countries regarding safety, efficacy, chemistry, manufacturing and controls, clinical trials, commercial sales, pricing and distribution of our product candidates. We may also rely on collaborators or partners to conduct the required activities to support an application for regulatory approval and to seek approval for one or more of our product candidates. We cannot be sure that any such collaborators or partners will conduct these activities successfully or do so within the timeframe we desire. Even if we or any future collaborators or partners are successful in obtaining approval in one jurisdiction, we cannot ensure that we will obtain approval in any other jurisdictions. If we are unable to obtain approval for our product candidates in multiple jurisdictions, our revenue and results of operations could be negatively affected.

Even if we receive regulatory approval to market any of our product candidates, we cannot assure you that any such product candidate will be successfully commercialized, widely accepted in the marketplace or more effective than other commercially available alternatives. Any approval we may obtain could be for indications or patient populations that are not as broad as intended or desired or may require labeling that includes significant use or distribution restrictions or safety warnings. We may also be required to perform additional or unanticipated clinical trials to obtain approval or be subject to additional post-marketing testing requirements to maintain approval. In addition, regulatory authorities may withdraw their approval of a product or impose restrictions on its distribution, such as in the form of a Risk Evaluation and Mitigation Strategy, or REMS. The failure to obtain timely regulatory approval of product candidates, any product marketing limitations or a product withdrawal would negatively impact our business, results of operations and financial condition.

We may encounter substantial delays in our clinical trials or may not be able to conduct or complete our clinical trials on the timelines we expect, if at all.

Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. We cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, if at all. We cannot be sure that submission of an IND or a clinical trial application, or CTA, will result in the FDA or other regulatory authority, as applicable, allowing clinical trials to begin in a timely manner, if at all. Moreover, even if these trials begin, issues may arise that could suspend or terminate such clinical trials. A failure of one or more clinical trials can occur at any stage of testing, and our future clinical trials may not be successful. Clinical trials can be delayed or terminated for a variety of reasons, including delays or failures related to:

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generating sufficient preclinical, toxicology or other in vivo or in vitro data to support the initiation or continuation of clinical trials;

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the FDA or comparable foreign regulatory authorities disagreeing as to the design or implementation of our clinical trials;

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delays in obtaining regulatory authorization to commence a trial;

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reaching agreements on acceptable terms with prospective CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;

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identifying, recruiting and training suitable clinical investigators;

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obtaining IRB approval at each trial site;

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imposition of a temporary or permanent clinical hold by regulatory agencies for a number of reasons, including after review of an IND or amendment, or equivalent foreign application or amendment;

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new safety findings that present unreasonable risk to clinical trial participants;

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a negative finding from an inspection of our clinical trial operations or study sites;

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recruiting an adequate number of suitable patients to participate in a trial;

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having subjects complete a trial or return for post-treatment follow-up;

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clinical trial sites deviating from trial protocol or dropping out of a trial;

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addressing subject safety concerns that arise during the course of a trial;

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adding a sufficient number of clinical trial sites; or

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obtaining sufficient product supply of product candidates for use in preclinical studies or clinical trials from third-party suppliers.

We may experience numerous adverse or unforeseen events during, or as a result of, preclinical studies and clinical trials which could delay or prevent our ability to receive marketing approval or commercialize our product candidates, including:

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we may receive feedback from regulatory authorities that requires us to modify the design of our clinical trials or require that we submit additional data or information before allowing a clinical trial to be initiated;

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clinical studies of our product candidates may produce negative or inconclusive results, and we may decide, or regulators may require us, to conduct additional clinical trials or abandon drug development programs;

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the number of patients required for clinical trials of our product candidates may be larger than we anticipate, enrollment in these clinical trials may be slower than we anticipate or participants may drop out of these clinical trials at a higher rate than we anticipate;

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our third-party contractors may fail to comply with regulatory requirements, fail to maintain adequate quality controls or be unable to provide us with sufficient product supply to conduct and complete preclinical studies or clinical trials of our product candidates in a timely manner, or at all;

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we or our investigators might have to suspend or terminate clinical trials of our product candidates for various reasons, including non-compliance with regulatory requirements, a finding that our product candidates have undesirable side effects or other unexpected characteristics or a finding that the participants are being exposed to unacceptable health risks;

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the cost of clinical trials of our product candidates may be greater than we anticipate;

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the quality of our product candidates or other materials necessary to conduct preclinical studies or clinical trials of our product candidates may be insufficient or inadequate;

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regulators may revise the requirements and add new requirements for approving our product candidates, or such requirements may not be as we anticipate; and

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any future collaborators may conduct clinical trials in ways they view as advantageous to them but that are suboptimal for us.

If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not positive or are only moderately positive or if there are safety concerns, we may:

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incur unplanned costs;

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be delayed in obtaining marketing approval for our product candidates or not obtain marketing approval at all;

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obtain marketing approval in some countries and not in others;

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obtain marketing approval for indications or patient populations that are not as broad as intended or desired;

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obtain marketing approval with labeling that includes significant use or distribution restrictions or safety warnings, including boxed warnings;

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be subject to additional post-marketing testing requirements; or

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have the product removed from the market after obtaining marketing approval.

For example, we intend to seek FDA approval of tanruprubart for the treatment of patients with GBS. Our data package is based on completed placebo-controlled studies conducted in Southeast Asia. We filed a MAA with the EMA for tanruprubart for the treatment of GBS in January 2026, and we continue to engage with EU regulators through the MAA review process. Tanruprubart has been granted orphan designation from the EMA. Tanruprubart has also been granted Fast Track and orphan drug designation for the treatment of GBS from the FDA. The currently ongoing open-label FORWARD study in the U.S. and Europe, which is designed to broaden Western experience with tanruprubart, and we anticipate initial PK, PD, biomarker and functional data in 2026 to supplement our comprehensive data package for tanruprubart in GBS. Following such data, we plan to engage with the FDA with the goal of reaching alignment on the sufficiency of our current and supplemental data package and information supporting the generalizability of tanruprubart in Western patients for submission of a BLA in 2026. In our discussions to date with the FDA, the FDA has indicated that the generalizability package may not be sufficient to support BLA approval absent additional patient data. While we expect that the inclusion of U.S. and European results from the FORWARD study will support a BLA submission in GBS, it is possible the FDA determines that our current package is not sufficient or requires us to provide additional data in GBS patients that are not feasible to obtain. Our inability to satisfy such additional requirements by the FDA may result in the FDA failing to approve tanruprubart in GBS, which would prevent the commercialization of tanruprubart in GBS in the United States, and limit the size of our commercial market opportunity and our potential future revenues, and could otherwise have a material adverse effect on our business.

We could also encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by the Data Safety Monitoring Board, or DSMB, for such trial or by the FDA or other regulatory authorities. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial.

Further, conducting clinical trials in foreign countries, as we plan to do for certain of our product candidates, presents additional risks that may delay completion of our clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs and managing additional administrative burdens associated with foreign regulatory schemes, as well as political and economic risks.

Principal investigators for our clinical trials may serve as scientific advisors or consultants to us from time to time and may receive cash or equity compensation in connection with such services. If these relationships and any related compensation result in perceived or actual conflicts of interest, or a regulatory authority concludes that the financial relationship may have affected the interpretation of the trial, the integrity of the data generated at the applicable clinical trial site may be questioned and the utility of the clinical trial itself may be jeopardized, which could result in the delay or rejection of the marketing application we submit. Any such delay or rejection could prevent or delay us from commercializing our current or future product candidates.

If we experience delays in the completion, or termination, of any preclinical study or clinical trial of our product candidates, the commercial prospects of our product candidates may be harmed, and our ability to generate revenues from any of these product candidates will be delayed or not realized at all. In addition, any delays in completing our clinical trials may increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues. Any of these occurrences may materially and adversely affect our business, financial condition, results of operations and prospects. In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates. If one or more of our product candidates proves to be ineffective, unsafe or commercially unviable, our business, financial condition, results of operations and prospects may be materially and adversely affected.

If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

We may not be able to initiate or continue clinical trials on a timely basis or at all for any product candidates we identify or develop if we are unable to locate and enroll a sufficient number of eligible patients to participate in the trials as required by applicable regulations or as needed to provide appropriate statistical power for a given trial. The timely completion of clinical trials in accordance with their protocols depends on, among other things, our ability to enroll a sufficient number of patients who remain in the study until

its conclusion. We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The enrollment of patients depends on many factors, including:

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the severity and difficulty of diagnosing the disease under investigation;

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the patient eligibility and exclusion criteria defined in the protocol;

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the size of the patient population required for analysis of the trial’s primary endpoints;

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the proximity of patients to trial sites;

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the design of the trial;

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our ability to recruit clinical trial investigators with the appropriate competencies and experience;

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the existing body of safety and efficacy data with respect to the study drug and safety concerns;

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patient referral practices of physicians;

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risk that enrolled subjects will drop out before completion of the trial, including as a result of health conditions or being forced to quarantine;

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ability to monitor patients adequately during and after treatment;

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availability and efficacy of approved medications or therapies, or other clinical trials, for the disease or condition under investigation;

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clinicians’ and patients’ perceptions as to the potential advantages of the product candidate being studied in relation to other available therapies, including any new drugs that may be approved for the indications we are investigating; and

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our ability to obtain and maintain patient consents.

Annexon, Inc. 10-Q