<SEC-DOCUMENT>0001415889-25-021708.txt : 20250814
<SEC-HEADER>0001415889-25-021708.hdr.sgml : 20250814
<ACCEPTANCE-DATETIME>20250814080707
ACCESSION NUMBER:		0001415889-25-021708
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250814
DATE AS OF CHANGE:		20250814

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXAGEN INC.
		CENTRAL INDEX KEY:			0001274737
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-91300
		FILM NUMBER:		251214483

	BUSINESS ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081
		BUSINESS PHONE:		(760) 560-1501

	MAIL ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXAGEN DIAGNOSTICS INC
		DATE OF NAME CHANGE:	20031230

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RTW INVESTMENTS, LP
		CENTRAL INDEX KEY:			0001493215
		ORGANIZATION NAME:           	
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		40 10TH AVENUE
		STREET 2:		7TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10014
		BUSINESS PHONE:		646-597-6980

	MAIL ADDRESS:	
		STREET 1:		40 10TH AVENUE
		STREET 2:		7TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10014

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RTW INVESTMENTS, LLC
		DATE OF NAME CHANGE:	20100602
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<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/A</submissionType>
		<previousAccessionNumber>0001493152-20-001141</previousAccessionNumber>
	    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001493215</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>





    </filerInfo>
  </headerData>

  <formData>
    <coverPageHeader>
		<amendmentNo>5</amendmentNo>
	      <securitiesClassTitle>Common Stock, par value $0.001 per share</securitiesClassTitle>
      <eventDateRequiresFilingThisStatement>06/30/2025</eventDateRequiresFilingThisStatement>
      <issuerInfo>
        <issuerCik>0001274737</issuerCik>        <issuerName>Exagen Inc.</issuerName>        <issuerCusip>30068X103</issuerCusip>
        <issuerPrincipalExecutiveOfficeAddress>
          <com:street1>1261 Liberty Way</com:street1>
                    <com:city>Vista</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>92081</com:zipCode>
        </issuerPrincipalExecutiveOfficeAddress>
      </issuerInfo>

	        <designateRulesPursuantThisScheduleFiled>
	   		        <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
				      </designateRulesPursuantThisScheduleFiled>

    </coverPageHeader>

	    <coverPageHeaderReportingPersonDetails>




    <reportingPersonName>RTW Investments, LP</reportingPersonName>



		 <citizenshipOrOrganization>DE</citizenshipOrOrganization>

      <reportingPersonBeneficiallyOwnedNumberOfShares>
                <soleVotingPower>0.00</soleVotingPower>
                          <sharedVotingPower>1696866.00</sharedVotingPower>
                          <soleDispositivePower>0.00</soleDispositivePower>
                         <sharedDispositivePower>1696866.00</sharedDispositivePower>
             </reportingPersonBeneficiallyOwnedNumberOfShares>

              <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1696866.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>


     	    <classPercent>7.7</classPercent>




	  	  	  	  <typeOfReportingPerson>IA</typeOfReportingPerson>

	        <typeOfReportingPerson>PN</typeOfReportingPerson>









    </coverPageHeaderReportingPersonDetails>
	    <coverPageHeaderReportingPersonDetails>




    <reportingPersonName>Roderick Wong</reportingPersonName>



		 <citizenshipOrOrganization>X1</citizenshipOrOrganization>

      <reportingPersonBeneficiallyOwnedNumberOfShares>
                <soleVotingPower>0.00</soleVotingPower>
                          <sharedVotingPower>1696866.00</sharedVotingPower>
                          <soleDispositivePower>0.00</soleDispositivePower>
                         <sharedDispositivePower>1696866.00</sharedDispositivePower>
             </reportingPersonBeneficiallyOwnedNumberOfShares>

              <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1696866.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>


     	    <classPercent>7.7</classPercent>







	        <typeOfReportingPerson>HC</typeOfReportingPerson>



	        <typeOfReportingPerson>IN</typeOfReportingPerson>




    </coverPageHeaderReportingPersonDetails>

    <items>
      <item1>
        <issuerName>Exagen Inc.</issuerName>
        <issuerPrincipalExecutiveOfficeAddress>1261 Liberty Way, Vista, CA, 92081.</issuerPrincipalExecutiveOfficeAddress>
      </item1>

      <item2>
        <filingPersonName>This statement is filed by.

(i)	RTW Investments, LP ("RTW Investments"), a Delaware limited partnership, and the investment adviser to certain funds (the "RTW Funds"), with respect to the Shares (as defined in Item 2(d) below) directly held by the RTW Funds; and

(ii)	Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds.

The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons."

The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares reported herein.
 </filingPersonName>        <principalBusinessOfficeOrResidenceAddress>The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014.</principalBusinessOfficeOrResidenceAddress>        <citizenship>RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States.</citizenship>      </item2>

        <item3>
				<notApplicableFlag>N</notApplicableFlag>





		<typeOfPersonFiling>IA</typeOfPersonFiling>

		<typeOfPersonFiling>HC</typeOfPersonFiling>







      </item3>



    <item4>
    <amountBeneficiallyOwned>The information required by Items 4(a) - (c) is set forth in Rows 5 - 11 of the cover page for each of the Reporting Persons and is incorporated herein by reference.

The percentages set forth herein are calculated based upon 21,998,739 Shares outstanding as of June 30, 2025, as reported in the Company's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025, filed with the Securities and Exchange Commission on July 29, 2025.</amountBeneficiallyOwned>
      <numberOfSharesPersonHas>




      </numberOfSharesPersonHas>
    </item4>


        <item5>
	          <notApplicableFlag>Y</notApplicableFlag>


    </item5>


        <item6>
	              <notApplicableFlag>N</notApplicableFlag>
        <ownershipMoreThan5PercentOnBehalfOfAnotherPerson>See Item 2. The RTW Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Shares reported herein. </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.</certifications>

      </item10>
    </items>


	    <signatureInformation>
      <reportingPersonName>RTW Investments, LP</reportingPersonName>

      <signatureDetails>
        <signature>/s/ Roderick Wong, M.D.</signature>
        <title>Roderick Wong, M.D., Managing Partner</title>
        <date>08/14/2025</date>
      </signatureDetails>

    </signatureInformation>
	     <signatureInformation>
      <reportingPersonName>Roderick Wong</reportingPersonName>

      <signatureDetails>
        <signature>s/ Roderick Wong, M.D.</signature>
        <title>Roderick Wong, M.D.</title>
        <date>08/14/2025</date>
      </signatureDetails>

    </signatureInformation>



  </formData>

    </edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
