<SEC-DOCUMENT>0001193125-26-291051.txt : 20260630
<SEC-HEADER>0001193125-26-291051.hdr.sgml : 20260630
<ACCEPTANCE-DATETIME>20260630190004
ACCESSION NUMBER:		0001193125-26-291051
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20260626
FILED AS OF DATE:		20260630
DATE AS OF CHANGE:		20260630

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Simson Jake
		CENTRAL INDEX KEY:			0001863094
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42382
		FILM NUMBER:		261142071

	MAIL ADDRESS:	
		STREET 1:		C/O JANUX THERAPEUTICS, INC.
		STREET 2:		11099 N. TORREY PINES ROAD, SUITE 290
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Septerna, Inc.
		CENTRAL INDEX KEY:			0001984086
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				843891440
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		250 EAST GRAND AVENUE, SUITE 65
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		650-338-3533

	MAIL ADDRESS:	
		STREET 1:		250 EAST GRAND AVENUE, SUITE 65
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-06-26</periodOfReport>

    <issuer>
        <issuerCik>0001984086</issuerCik>
        <issuerName>Septerna, Inc.</issuerName>
        <issuerTradingSymbol>SEPN</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001863094</rptOwnerCik>
            <rptOwnerName>Simson Jake</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O SEPTERNA, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>250 EAST GRAND AVENUE</rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>37.34</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-06-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2036-06-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares underlying the stock option vest in full upon the earlier of (i) June 26, 2027 or (ii) the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service to the Issuer through such vesting date.</footnote>
        <footnote id="F2">Under the Reporting Person's arrangement with RA Capital Management, L.P. (the &quot;Adviser&quot;), the Reporting Person holds the option for the benefit of the R.A. Capital Healthcare Fund, L.P. (the &quot;Fund&quot;) and R.A. Capital Nexus Fund III, L.P. (the &quot;Nexus Fund III&quot;). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund and the Nexus Fund III to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and underlying common stock.</footnote>
    </footnotes>

    <remarks>Exhibit 24.2 - Substitute Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Mark A. Wilson, Attorney-in-Fact</signatureName>
        <signatureDate>2026-06-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.2
<SEQUENCE>2
<FILENAME>sepn-ex24_2.htm
<DESCRIPTION>EX-24.2
<TEXT>
<!-- DFIN ActiveDisclosure (SM) HTML Document - http://www.dfinsolutions.com/ --><!-- Creation Date :2026-06-30T14:42:35.1113+00:00 --><!-- Copyright (c) 2026 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <title>EX-24.2</title>
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 <body style="padding:8px;margin:auto!important;z-index:0;-webkit-text-size-adjust:100%;position:relative;">
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  <div class="main-content-container" style="z-index:5;position:relative;"><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">SUBSTITUTE POWER OF ATTORNEY</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Under the terms of powers of attorney (each, a &#34;Power of Attorney&#34;) previously filed with the U.S. Securities and Exchange Commission, the undersigned was appointed an attorney-in-fact for the below listed individuals to, among other things, execute for and on behalf of the following individuals any Form 3, Form 4, Form 5, Schedule 13D, or Schedule 13G, or any amendment(s) thereto, in accordance with Section 13 or Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder:</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Abraham Bassan</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Liz Bhatt</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Bernard Coulie</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Alan Ezekowitz</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Jeffrey Finer</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Jae B. Kim</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Uwe Klein</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Daniel D. Long</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Shalini Sharp</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Jake Simson</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Samira Shaikhly</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Jeffrey K. Tong</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">In accordance with the authority granted under each Power of Attorney, including the full power of substitution, the undersigned hereby appoints each of Gil M. Labrucherie and Mark A. Wilson, as substitute attorneys-in-fact, on behalf of the individuals listed above, with the power to exercise and execute all of the powers granted or conferred in the original Power of Attorney. For the avoidance of doubt, the foregoing appointment shall not serve as a revocation of the powers granted to the undersigned herself in each Power of Attorney.</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">This substitute Power of Attorney shall remain in full force and effect with respect to each Power of Attorney until such underlying Power of Attorney is revoked or terminated, unless earlier revoked by the undersigned in a signed writing.</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Date: February 10, 2026</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="white-space:pre-wrap;font-size:10.5pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">By: /s/ Ran Xiao</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Name: Ran Xiao</font></p><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Title: Attorney-in-Fact</font></p></div>
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