<SEC-DOCUMENT>0000935836-25-000295.txt : 20250428
<SEC-HEADER>0000935836-25-000295.hdr.sgml : 20250428
<ACCEPTANCE-DATETIME>20250428191512
ACCESSION NUMBER:		0000935836-25-000295
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20250428
DATE AS OF CHANGE:		20250428

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Annexon, Inc.
		CENTRAL INDEX KEY:			0001528115
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				275414423
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-91583
		FILM NUMBER:		25882166

	BUSINESS ADDRESS:	
		STREET 1:		1400 SIERRA POINT PARKWAY
		STREET 2:		BLDG C, SUITE 200
		CITY:			BRISBANE
		STATE:			CA
		ZIP:			94005
		BUSINESS PHONE:		(650)-822-5500

	MAIL ADDRESS:	
		STREET 1:		1400 SIERRA POINT PARKWAY
		STREET 2:		BLDG C, SUITE 200
		CITY:			BRISBANE
		STATE:			CA
		ZIP:			94005

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Logos Global Management LP
		CENTRAL INDEX KEY:			0001792126
		ORGANIZATION NAME:           	
		EIN:				833997742
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G

	BUSINESS ADDRESS:	
		STREET 1:		1 LETTERMAN DRIVE
		STREET 2:		BLDG C, SUITE C3-350
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94129
		BUSINESS PHONE:		4158014660

	MAIL ADDRESS:	
		STREET 1:		1 LETTERMAN DRIVE
		STREET 2:		BLDG C, SUITE C3-350
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94129
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/schedule13g" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>SCHEDULE 13G</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <!-- Field: Pseudo-Tag; ID: Name; Data: Logos Global Management LP -->
          <cik>0001792126</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <coverPageHeader>
      <securitiesClassTitle>Common Stock</securitiesClassTitle>
      <eventDateRequiresFilingThisStatement>04/21/2025</eventDateRequiresFilingThisStatement>
      <issuerInfo>
        <issuerCik>0001528115</issuerCik>
        <issuerName>Annexon, Inc.</issuerName>
        <issuerCusip>03589W102</issuerCusip>
        <issuerPrincipalExecutiveOfficeAddress>
          <com:street1>1400 SIERRA POINT PARKWAY</com:street1>
          <com:street2>BLDG C, SUITE 200</com:street2>
          <com:city>BRISBANE</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94005</com:zipCode>
        </issuerPrincipalExecutiveOfficeAddress>
      </issuerInfo>
      <designateRulesPursuantThisScheduleFiled>
        <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
        <designateRulePursuantThisScheduleFiled>Rule 13d-1(c)</designateRulePursuantThisScheduleFiled>
      </designateRulesPursuantThisScheduleFiled>
    </coverPageHeader>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Logos Global Management LP</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>DE</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0.00</soleVotingPower>
        <sharedVotingPower>6600000.00</sharedVotingPower>
        <soleDispositivePower>0.00</soleDispositivePower>
        <sharedDispositivePower>6600000.00</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>6600000.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>6.0</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
      <typeOfReportingPerson>PN</typeOfReportingPerson>
      <comments>Percentage calculated based on 109,709,826 shares of Common Stock outstanding on February 28, 2025, as reported in the Form 10-K filed by the Issuer for the fiscal year ended December 31, 2024.</comments>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>

      <reportingPersonName>Logos Global Management GP LLC</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>DE</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0.00</soleVotingPower>
        <sharedVotingPower>6600000.00</sharedVotingPower>
        <soleDispositivePower>0.00</soleDispositivePower>
        <sharedDispositivePower>6600000.00</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>6600000.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>6.0</classPercent>
      <typeOfReportingPerson>HC</typeOfReportingPerson>
      <typeOfReportingPerson>OO</typeOfReportingPerson>
      <comments>Percentage calculated based on 109,709,826 shares of Common Stock outstanding on February 28, 2025, as reported in the Form 10-K filed by the Issuer for the fiscal year ended December 31, 2024.</comments>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Logos Global Master Fund LP</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>E9</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0.00</soleVotingPower>
        <sharedVotingPower>6600000.00</sharedVotingPower>
        <soleDispositivePower>0.00</soleDispositivePower>
        <sharedDispositivePower>6600000.00</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>6600000.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>6.0</classPercent>
      <typeOfReportingPerson>PN</typeOfReportingPerson>
      <comments>Percentage calculated based on 109,709,826 shares of Common Stock outstanding on February 28, 2025, as reported in the Form 10-K filed by the Issuer for the fiscal year ended December 31, 2024.</comments>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>

      <reportingPersonName>Logos GP LLC</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>X1</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0.00</soleVotingPower>
        <sharedVotingPower>6600000.00</sharedVotingPower>
        <soleDispositivePower>0.00</soleDispositivePower>
        <sharedDispositivePower>6600000.00</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>6600000.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>6.0</classPercent>
      <typeOfReportingPerson>HC</typeOfReportingPerson>
      <typeOfReportingPerson>OO</typeOfReportingPerson>
      <comments>Percentage calculated based on 109,709,826 shares of Common Stock outstanding on February 28, 2025, as reported in the Form 10-K filed by the Issuer for the fiscal year ended December 31, 2024.</comments>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Arsani William</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>X1</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0.00</soleVotingPower>
        <sharedVotingPower>6600000.00</sharedVotingPower>
        <soleDispositivePower>0.00</soleDispositivePower>
        <sharedDispositivePower>6600000.00</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>6600000.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>6.0</classPercent>
      <typeOfReportingPerson>HC</typeOfReportingPerson>
      <typeOfReportingPerson>IN</typeOfReportingPerson>
      <comments>Percentage calculated based on 109,709,826 shares of Common Stock outstanding on February 28, 2025, as reported in the Form 10-K filed by the Issuer for the fiscal year ended December 31, 2024.</comments>
    </coverPageHeaderReportingPersonDetails>
    <items>
      <item1>
        <issuerName>Annexon, Inc.</issuerName>
        <issuerPrincipalExecutiveOfficeAddress>1400 Sierra Point Parkway, Bldg C, Suite 200, Brisbane, CA 94005</issuerPrincipalExecutiveOfficeAddress>
      </item1>
      <item2>
        <filingPersonName>Logos Global Management LP ("Logos Global")

Logos Global Management GP LLC ("Logos Global GP")

Logos Global Master Fund LP ("Global Fund")

Logos GP LLC ("Logos GP")

Arsani William

Logos Global is the investment adviser to investment funds, including Global Fund.  Logos Global GP is the general partner of Logos Global.  Logos GP is the general partner of Global Fund.  Dr. William is a control person of Logos Global, Logos Global GP and Logos GP.

The reporting persons are filing this statement jointly but not as members of a group, and they expressly disclaim membership in a group.  Each reporting person disclaims beneficial ownership of Common Stock except to the extent of that person's pecuniary interest therein.  In addition, the filing of this Schedule 13G on behalf of the Global Fund should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any Common Stock covered by this Schedule 13G.</filingPersonName>
        <principalBusinessOfficeOrResidenceAddress>One Letterman Drive, Building C, Suite C3-350, San Francisco, California 94129</principalBusinessOfficeOrResidenceAddress>
        <citizenship>See Item 4 of the cover sheet for each reporting person.</citizenship>
      </item2>
      <item3>
        <notApplicableFlag>N</notApplicableFlag>
        <typeOfPersonFiling>IA</typeOfPersonFiling>
        <typeOfPersonFiling>HC</typeOfPersonFiling>
      </item3>
      <item4>
        <amountBeneficiallyOwned>Logos Global:  6,600,000

Logos Global GP:  6,600,000

Global Fund:  6,600,000

Logos GP:  6,600,000

Arsani William:  6,600,000</amountBeneficiallyOwned>
        <classPercent>Logos Global:  6.0%

Logos Global GP:  6.0%

Global Fund:  6.0%

Logos GP:  6.0%

Arsani William:  6.0%</classPercent>
        <numberOfSharesPersonHas>
          <solePowerOrDirectToVote>Logos Global:  0

Logos Global GP:  0

Global Fund:  0

Logos GP:  0

Arsani William:  0</solePowerOrDirectToVote>
          <sharedPowerOrDirectToVote>Logos Global:  6,600,000

Logos Global GP:  6,600,000

Global Fund:  6,600,000

Logos GP:  6,600,000

Arsani William:  6,600,000</sharedPowerOrDirectToVote>
          <solePowerOrDirectToDispose>Logos Global:  0

Logos Global GP:  0

Global Fund:  0

Logos GP:  0

Arsani William:  0</solePowerOrDirectToDispose>
          <sharedPowerOrDirectToDispose>Logos Global:  6,600,000

Logos Global GP:  6,600,000

Global Fund:  6,600,000

Logos GP:  6,600,000

Arsani William:  6,600,000</sharedPowerOrDirectToDispose>
        </numberOfSharesPersonHas>
      </item4>
      <item5>
        <notApplicableFlag>Y</notApplicableFlag>
      </item5>
      <item6>
        <notApplicableFlag>N</notApplicableFlag>
        <ownershipMoreThan5PercentOnBehalfOfAnotherPerson>Global Fund holds the Common Stock for the benefit of its investors and has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock.</ownershipMoreThan5PercentOnBehalfOfAnotherPerson>
      </item6>
      <item7>
        <notApplicableFlag>Y</notApplicableFlag>
      </item7>
      <item8>
        <notApplicableFlag>Y</notApplicableFlag>
      </item8>
      <item9>
        <notApplicableFlag>Y</notApplicableFlag>
      </item9>
      <item10>
        <notApplicableFlag>N</notApplicableFlag>
        <certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.</certifications>
      </item10>
    </items>
    <signatureInformation>
      <reportingPersonName>Logos Global Management LP</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Arsani William</signature>
        <title>Managing Partner</title>
        <date>04/28/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Logos Global Management GP LLC</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Arsani William</signature>
        <title>Managing Member</title>
        <date>04/28/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Logos Global Master Fund LP</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Arsani William</signature>
        <title>Managing Member of Logos GP LLC, General Partner of Logos Global Master Fund LP</title>
        <date>04/28/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Logos GP LLC</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Arsani William</signature>
        <title>Managing Member</title>
        <date>04/28/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Arsani William</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Arsani William</signature>
        <title>Reporting person</title>
        <date>04/28/2025</date>
      </signatureDetails>
    </signatureInformation>
  </formData>

</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1 AGREEMENT
<SEQUENCE>2
<FILENAME>exh99agmt.htm
<TEXT>
<HTML>
<HEAD>
     <TITLE></TITLE>
</HEAD>
<BODY STYLE="font: 10pt Times New Roman, Times, Serif">

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center">EXHIBIT 99.1</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center">AGREEMENT REGARDING JOINT FILING</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center">OF STATEMENT ON SCHEDULE 13D OR 13G</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: justify">The undersigned agree to file jointly with
the Securities and Exchange Commission (the &ldquo;SEC&rdquo;) any and all statements on Schedule 13D, Schedule 13G or forms 3, 4 or 5
(and any amendments or supplements thereto) required under section 13(d) or 16(a) of the Securities Exchange Act of 1934, as amended,
in connection with purchases by the undersigned of the securities of any issuer. For that purpose, the undersigned hereby constitute and
appoint Logos Global Management LP, a Delaware limited partnership, as their true and lawful agent and attorney-in-fact, with full power
and authority for and on behalf of the undersigned to prepare or cause to be prepared, sign, file with the SEC and furnish to any other
person all certificates, instruments, agreements and documents necessary to comply with section 13(d) and section 16(a) of the Act, in
connection with said purchases, and to do and perform every act necessary and proper to be done incident to the exercise of the foregoing
power, as fully as the undersigned might or could do if personally present.</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt">Dated:<B>&#9;</B>April 28, 2025</P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; border-collapse: collapse">
  <TR STYLE="vertical-align: top">
    <TD STYLE="width: 50%; padding-right: 5.4pt; padding-left: 5.4pt">
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><U>/s/ <I>Arsani William</I>&#9;&#9;&#9;</U><B><BR>
    Arsani William</B></P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P></TD>
    <TD STYLE="width: 50%; padding-right: 5.4pt; padding-left: 5.4pt; font: 12pt Times New Roman, Times, Serif">&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="font: 12pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"><FONT STYLE="font-size: 11pt"><B>Logos Global Management LP</B><BR>
<BR>
<BR>
By:&#9;<U>/s/ <I>Arsani William</I>&#9;&#9;&#9;</U><BR>
&#9;Arsani William, Managing Partner</FONT></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt">
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><B>Logos Global Master Fund LP</B></P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">By Logos GP LLC, its General Partner</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">By:&#9;<U>/s <I>Arsani William&#9;&#9;&#9;</I></U><BR>
    &#9;Arsani William, Managing Member</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><B>&nbsp;</B></P></TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt">
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><B>Logos Global Management GP LLC</B><BR>
    <BR>
    <BR>
    By:&#9;<U>/s/ <I>Arsani William</I>&#9;&#9;&#9;</U><BR>
    &#9;Arsani William, Managing Member</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><B>&nbsp;</B></P></TD>
    <TD STYLE="padding-right: 5.4pt; padding-left: 5.4pt">
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0"><B>Logos GP LLC</B><BR>
    <BR>
    <BR>
    By:&#9;<U>/s/ <I>Arsani William&#9;&#9;&#9;</I></U><BR>
    &#9;Arsani William, Managing Member</P>
    <P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0">&nbsp;</P></TD></TR>
  </TABLE>

</BODY>
</HTML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
