<SEC-DOCUMENT>0001178937-25-000061.txt : 20251117
<SEC-HEADER>0001178937-25-000061.hdr.sgml : 20251117
<ACCEPTANCE-DATETIME>20251117164637
ACCESSION NUMBER:		0001178937-25-000061
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20251117
DATE AS OF CHANGE:		20251117

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Sionna Therapeutics, Inc.
		CENTRAL INDEX KEY:			0002036042
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	001-42504
		FILM NUMBER:		251491619

	BUSINESS ADDRESS:	
		STREET 1:		21 HICKORY DRIVE, SUITE 500
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		617-819-2020

	MAIL ADDRESS:	
		STREET 1:		21 HICKORY DRIVE, SUITE 500
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RA Capital Healthcare Fund LP
		CENTRAL INDEX KEY:			0001315082
		ORGANIZATION NAME:           	
		EIN:				830406780
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144

	BUSINESS ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		6177782500

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RA Capital Biotech Fund LP
		DATE OF NAME CHANGE:	20050121
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001315082</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0002036042</issuerCik>
      <issuerName>Sionna Therapeutics, Inc.</issuerName>
      <secFileNumber>001-42504</secFileNumber>
      <issuerAddress>
        <com:street1>21 HICKORY DRIVE, SUITE 500</com:street1>
        <com:city>WALTHAM</com:city>
        <com:stateOrCountry>MA</com:stateOrCountry>
        <com:zipCode>02451</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>617-819-2020</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>RA Capital Healthcare Fund LP</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Director</relationshipToIssuer>
        <relationshipToIssuer>10% Stockholder</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>BTIG, LLC</name>
        <address>
          <com:street1>350 Bush Street</com:street1>
          <com:street2>9th Floor</com:street2>
          <com:city>San Francisco</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94104</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>3936</noOfUnitsSold>
      <aggregateMarketValue>157164.00</aggregateMarketValue>
      <noOfUnitsOutstanding>44628788</noOfUnitsOutstanding>
      <approxSaleDate>11/17/2025</approxSaleDate>
      <securitiesExchangeName>NASDAQ GM</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>02/02/2022</acquiredDate>
      <natureOfAcquisitionTransaction>Private Transaction</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Sionna Therapeutics</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>3936</amountOfSecuritiesAcquired>
      <paymentDate>02/02/2022</paymentDate>
      <natureOfPayment>Wire</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>RA Capital Healthcare Fund, L.P</name>
        <address>
          <com:street1>200 BERKELEY STREET</com:street1>
          <com:street2>18TH FLOOR</com:street2>
          <com:city>BOSTON</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02116</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>10/24/2025</saleDate>
      <amountOfSecuritiesSold>14116</amountOfSecuritiesSold>
      <grossProceeds>557582.00</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>RA Capital Healthcare Fund, L.P</name>
        <address>
          <com:street1>200 BERKELEY STREET, 18TH FLOOR</com:street1>
          <com:city>BOSTON</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02116</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>10/28/2025</saleDate>
      <amountOfSecuritiesSold>3624</amountOfSecuritiesSold>
      <grossProceeds>142967.00</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>11/17/2025</noticeDate>
      <signature>Rajeev Shah</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
