October 15, 2019

Douglas Love, Esq.
President and Chief Executive Officer
Annexon, Inc.
180 Kimball Way, Suite 200
South San Francisco, CA 94080

       Re: Annexon, Inc.
           Draft Registration Statement on Form S-1
           Submitted September 18, 2019
           CIK No. 0001528115

Dear Mr. Love:

       We have reviewed your draft registration statement and have the
following comments. In
some of our comments, we may ask you to provide us with information so we may
understand your disclosure.

       Please respond to this letter by providing the requested information and
either submitting
an amended draft registration statement or publicly filing your registration
statement on
EDGAR. If you do not believe our comments apply to your facts and circumstances
or do not
believe an amendment is appropriate, please tell us why in your response.

      After reviewing the information you provide in response to these comments
and your
amended draft registration statement or filed registration statement, we may
have additional

Draft Registration Statement on Form S-1 submitted September 18, 2019

Prospectus Summary
Overview, page 1

1.     With reference to your disclosure on page 104, please revise your
Summary to provide
       context to all efficacy performance claims where your clinical studies
were not
       statistically powered for efficacy evaluations. For instance, it should
be clear, if true, that
       you do not have statistically significant trial results to support your
claims concerning
       "full inhibition of C1q and the classical complement pathway" for ANX005
       ANX007. Also, it should be clear that the "positive numerical trends
across key GBS
       outcome measures" for ANX005 do not equate to statistically significant
trial results.
 Douglas Love, Esq.
Annexon, LastNameDouglas Love, Esq.
Comapany NameAnnexon, Inc.
October 15, 2019
Page 2
October 15, 2019 Page 2
FirstName LastName
2.       Where you state that you "hold worldwide development and
commercialization rights" to
         your product candidates, please revise your disclosure to specify, if
true, that you
         exclusively license some of these rights.
Our Pipeline, page 3

3.       Please revise the penultimate paragraph on page 3 to indicate whether
the ANX005 and
         IVIg combination trial is a Phase 1 or Phase 2 clinical trial. With
reference to the risk
         factor disclosure on page 23, revise the page 3 disclosure to discuss
briefly the purpose
         and limitations of the planned combination trial. With a view to
disclosure, please also
         tell us why you are conducting a Phase 2 monotherapy trial given your
disclosure on page
         18 that you intend to pursue a Phase 3 trial utilizing a combination
of ANX005 and IVIg.
         Also revise the Product Candidate, Phase, Status columns in the
Pipeline table, as

4.       We note your disclosure in the footnote of the pipeline table that you
intend to initiate
         Phase 2 clinical trials in the follow-on disease indications for
ANX005 following
         clearance of the applicable investigational new drug applications
(INDs). Please disclose
         whether you have filed INDs for each of the indications you plan to
Implications of Being an Emerging Growth Company, page 6

5.       Please supplementally provide us with copies of all written
communications, as defined in
         Rule 405 under the Securities Act, that you, or anyone authorized to
do so on your behalf,
         present to potential investors in reliance on Section 5(d) of the
Securities Act, whether or
         not they retain copies of the communications.
Clinical trials of ANX005..., page 23

6.       To the extent known, please revise to discuss here or elsewhere the
reasons why IVIg is
         not approved to treat GBS in the United States.
Management's Discussion and Analysis
Critical Accounting Policies and Estimates
Stock-Based Compensation
Common Stock Valuations, page 89

7.       Once you have an estimated offering price or range, please explain to
us how you
         determined the fair value of the common stock underlying your equity
issuances and the
         reasons for any differences between the recent valuations of your
common stock leading
         up to the IPO and the estimated offering price. This information will
help facilitate our
         review of your accounting for equity issuances including stock
compensation and
         beneficial conversion features.
 Douglas Love, Esq.
Annexon, LastNameDouglas Love, Esq.
Comapany NameAnnexon, Inc.
October 15, 2019
October 15, 2019 Page 3
Page 3
FirstName LastName
Our Pipeline, page 100

8.       Please define the terms IgG and CAD at first use. Please also discuss
the significance
         of the p-value and r2 where first used.

9.       Please provide us proofs of all graphics, visual, or photographic
information you will
         provide in the printed prospectus prior to its use, for example in a
preliminary prospectus.
         Please note that we may have comments regarding this material.
        You may contact Mary Mast at (202) 551-3613 or Angela Connell,
Accounting Branch
Chief, at (202) 551-3426 if you have questions regarding comments on the
financial statements
and related matters. Please contact Irene Paik at (202) 551-6553 or Joseph
McCann at
(202) 551-6262 with any other questions.


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