Exhibit 99.1

Annexon Biosciences Reports Fourth Quarter and Full-Year 2020 Financial Results

with Recent Business Highlights

SOUTH SAN FRANCISCO, Calif., March 25, 2021 – Today Annexon, Inc.  (“Annexon”) (Nasdaq: ANNX), a clinical-stage biopharmaceutical company developing a pipeline of novel therapies for patients with classical complement-mediated disorders of the body, brain and eye, announced fourth quarter and full-year 2020 financial results and business highlights.

Recent Business Highlights

Annexon continues to make strong progress in advancing its broad and deep pipeline and clinical programs across a  range of potential indications.  Recent highlights include:

Full results from the DDI study are expected to be submitted to a peer-reviewed forum in 2021.  A placebo-controlled Phase 2/3 trial is ongoing to evaluate the efficacy of ANX005 monotherapy in improving disability in GBS patients.  Data from the Phase 2/3 trial is anticipated in 2023.

“We continue to make progress against our vision of building a leading, multi-faceted complement therapeutics company with an innovative portfolio for a broad range of autoimmune, neurodegenerative and ophthalmic diseases,” said Douglas Love, Esq., president and chief executive officer of Annexon.  “The DDI data gives us further confidence in ANX005.  We are rapidly advancing multiple Phase 2 clinical programs across a diverse set of potential indications, and accelerating development of a number of innovative, next generation product candidates.  This clinical momentum coupled with our strong capital position positions us well to drive value in 2021 and beyond.”

Fourth Quarter and Full-Year 2020 Financial Results

About Annexon, Inc.

Annexon is a clinical-stage biopharmaceutical company developing a pipeline of novel therapies for patients with classical complement-mediated disorders of the body, brain and eye. The company’s pipeline is based on its platform technology addressing well-researched classical complement-mediated autoimmune and neurodegenerative disease processes, both of which are triggered by aberrant activation of C1q, the initiating molecule of the classical complement pathway. Annexon is deploying a disciplined, biomarker-driven strategy designed to select indications, identify patients and to measure target engagement and response to treatment with its drug candidates. For more information, visit www.annexonbio.com.

Forward Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended.  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,” “positioned,” “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 or other comparable terminology.  All statements other than statements of historical facts contained in this press release are forward-looking statements.  These forward-looking statements include, but are not limited to, statements about: advancement of the company’s clinical and preclinical programs; timing of data from clinical trials and submission of data to peer-reviewed forums; confidence in the company’s product candidates; the company’s ability to drive value in 2021 and beyond; and the implementation of the company’s business model and strategic plans for its business and product candidates, including potential treatment indications and additional indications that the company may pursue.  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 materially from those anticipated, including, but not limited to, risks and uncertainties related to: the company’s history of net operating losses; the company’s ability to obtain necessary capital to fund its clinical programs; the early stages of clinical development of the company’s product candidates; the effects of COVID-19 or other public health crises on the company’s clinical programs and business operations; the company’s ability to obtain regulatory approval of and successfully commercialize its product candidates; any undesirable side effects or other properties of the company’s product candidates; the company’s reliance on third-party suppliers and manufacturers; the outcomes of any future collaboration agreements; and the company’s ability to adequately maintain intellectual property rights for its product candidates.  These and other risks are described in greater detail under the section titled “Risk Factors” contained in the company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q and the company’s other filings with the SEC. Any forward-looking statements that the company makes in this press release are made pursuant to the Private Securities Litigation Reform Act of 1995, as amended, and speak only as of the date of this press release.  Except as required by law, the company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.

Investor Contacts:
Jennifer Lew, Chief Financial Officer

Annexon Biosciences

jlew@annexonbio.com

Sara Michelmore

smichelmore@macbiocom.com

Media Contacts:
Miriam Mason

Annexon Biosciences

mmason@annexonbio.com

Caroline Rufo, Ph.D.

crufo@macbiocom.com

ANNEXON, INC.

Condensed Consolidated Statements of Operations

(in thousands, except share and per share amounts)

ANNEXON, INC.

Condensed Consolidated Balance Sheets

(in thousands)