<SEC-DOCUMENT>0002100121-26-000087.txt : 20260428
<SEC-HEADER>0002100121-26-000087.hdr.sgml : 20260428
<ACCEPTANCE-DATETIME>20260428160530
ACCESSION NUMBER:		0002100121-26-000087
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20260428
DATE AS OF CHANGE:		20260428

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARROWHEAD PHARMACEUTICALS, INC.
		CENTRAL INDEX KEY:			0000879407
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				460408024
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-48710
		FILM NUMBER:		26907587

	BUSINESS ADDRESS:	
		STREET 1:		177 E COLORADO BLVD
		STREET 2:		SUITE 700
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
		BUSINESS PHONE:		626-696-4702

	MAIL ADDRESS:	
		STREET 1:		177 E COLORADO BLVD
		STREET 2:		SUITE 700
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ARROWHEAD RESEARCH CORP
		DATE OF NAME CHANGE:	20040112

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERACTIVE GROUP INC
		DATE OF NAME CHANGE:	20020509

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERACTIVE INC
		DATE OF NAME CHANGE:	19940224

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			VANGUARD PORTFOLIO MANAGEMENT LLC
		CENTRAL INDEX KEY:			0002100121
		ORGANIZATION NAME:           	
		EIN:				392888838
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231
		LEGAL ENTITY IDENTIFIER:    	529900YN99W7NU4H6B84

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G

	BUSINESS ADDRESS:	
		STREET 1:		100 VANGUARD BLVD
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
		BUSINESS PHONE:		610-669-6148

	MAIL ADDRESS:	
		STREET 1:		100 VANGUARD BLVD
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
</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">
<schemaVersion>X0202</schemaVersion>
<headerData>
<submissionType>SCHEDULE 13G</submissionType>
<filerInfo>
<filer>
<filerCredentials>
<cik>0002100121</cik>
<ccc>XXXXXXXX</ccc>
</filerCredentials>
</filer>
<liveTestFlag>LIVE</liveTestFlag>
</filerInfo>
</headerData>
<formData>
<coverPageHeader>
<securitiesClassTitle>Common Stock</securitiesClassTitle>
<eventDateRequiresFilingThisStatement>03/31/2026</eventDateRequiresFilingThisStatement>
<issuerInfo>
<issuerCik>0000879407</issuerCik>
<issuerName>Arrowhead Pharmaceuticals Inc</issuerName>
<issuerCusips>
<issuerCusipNumber>04280A100</issuerCusipNumber>
</issuerCusips>
<issuerPrincipalExecutiveOfficeAddress>
<com:street1>177 East Colorado Blvd</com:street1>
<com:street2>Suite 700</com:street2>
<com:city>Pasadena</com:city>
<com:stateOrCountry>CA</com:stateOrCountry>
<com:zipCode>91105</com:zipCode>
</issuerPrincipalExecutiveOfficeAddress>
</issuerInfo>
<designateRulesPursuantThisScheduleFiled>
<designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
</designateRulesPursuantThisScheduleFiled>
</coverPageHeader>
<coverPageHeaderReportingPersonDetails>
<reportingPersonName>Vanguard Portfolio Management</reportingPersonName>
<citizenshipOrOrganization>PA</citizenshipOrOrganization>
<reportingPersonBeneficiallyOwnedNumberOfShares>
<soleVotingPower>123821</soleVotingPower>
<sharedVotingPower>0</sharedVotingPower>
<soleDispositivePower>7269957</soleDispositivePower>
<sharedDispositivePower>0</sharedDispositivePower>
</reportingPersonBeneficiallyOwnedNumberOfShares>
<reportingPersonBeneficiallyOwnedAggregateNumberOfShares>7269957</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
<classPercent>5.19</classPercent>
<typeOfReportingPerson>IA</typeOfReportingPerson>
<comments>
In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by Vanguard Portfolio Management LLC and the following affiliates of Vanguard Portfolio Management LLC or business divisions of such affiliates: Vanguard Fiduciary Trust Company and Vanguard Global Advisers, LLC. This Schedule 13G includes securities held by Vanguard funds, or sleeves thereof, over which Vanguard Portfolio Management LLC exercises dispositive power, in addition to securities held by clients over which the affiliates or business divisions of such affiliates indicated above exercise dispositive and/or voting power. This Schedule 13G does not include securities, if any, beneficially owned by other subsidiaries or affiliates of Vanguard Portfolio Management LLC, or business divisions of such subsidiaries whose ownership of securities is disaggregated from that of the reporting business unit in accordance with such release.

</comments>
</coverPageHeaderReportingPersonDetails>
<items>
<item1>
<issuerName>Arrowhead Pharmaceuticals Inc</issuerName>
<issuerPrincipalExecutiveOfficeAddress>177 East Colorado Blvd, Suite 700, Pasadena, CA, 91105</issuerPrincipalExecutiveOfficeAddress>
</item1>
<item2>
<filingPersonName>Vanguard Portfolio Management</filingPersonName>
<principalBusinessOfficeOrResidenceAddress>100 Vanguard Blvd,, Malvern, PA, 19355</principalBusinessOfficeOrResidenceAddress>
<citizenship>PA</citizenship>
</item2>
<item3>
<notApplicableFlag>N</notApplicableFlag>
<typeOfPersonFiling>IA</typeOfPersonFiling>
</item3>
<item4>
<amountBeneficiallyOwned>7269957</amountBeneficiallyOwned>
<classPercent>5.19</classPercent>
<numberOfSharesPersonHas>
<solePowerOrDirectToVote>123821</solePowerOrDirectToVote>
<sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
<solePowerOrDirectToDispose>7269957</solePowerOrDirectToDispose>
<sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
</numberOfSharesPersonHas>
</item4>
<item5>
<notApplicableFlag>Y</notApplicableFlag>
</item5>
<item6>
<notApplicableFlag>N</notApplicableFlag>
<ownershipMoreThan5PercentOnBehalfOfAnotherPerson>Vanguard Portfolio Management, including investment companies registered under the Investment Company Act of 1940 and other managed accounts, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities reported herein.No one other person's interest in the securities reported herein is more than 5%.</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 &amp;#167; 240.14a-11.</certifications>
</item10>
</items>
<signatureInformation>
<reportingPersonName>Vanguard Portfolio Management</reportingPersonName>
<signatureDetails>
<signature>Ashley Grim</signature>
<title>Head of Global Fund Administration</title>
<date>04/28/2026</date>
</signatureDetails>
</signatureInformation>
</formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
