content: <?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>
            <!-- Field: Pseudo-Tag; ID: Name; Data: ORBIMED ADVISORS LLC -->
            <cik>0001055951</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001787297</issuerCik>
        <issuerName>Passage BIO, Inc.</issuerName>
        <secFileNumber>001-39231</secFileNumber>
        <issuerAddress>
          <com:street1>One Commerce Square</com:street1>
          <com:street2>2005 Market Street, 39th Floor</com:street2>
          <com:city>Philadelphia</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19103</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>267-866-0312</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>OrbiMed Private Investments VII, LP</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Stockholder</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Themis Trading LLC</name>
          <address>
            <com:street1>10 Town Square</com:street1>
            <com:street2>Suite 100</com:street2>
            <com:city>Chatham</com:city>
            <com:stateOrCountry>NJ</com:stateOrCountry>
            <com:zipCode>07928</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>53293</noOfUnitsSold>
        <aggregateMarketValue>361859.47</aggregateMarketValue>
        <noOfUnitsOutstanding>3120295</noOfUnitsOutstanding>
        <approxSaleDate>07/15/2025</approxSaleDate>
        <securitiesExchangeName>Nasdaq Stock Market</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>03/03/2020</acquiredDate>
        <natureOfAcquisitionTransaction>IPO</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>53293</amountOfSecuritiesAcquired>
        <paymentDate>03/03/2020</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/15/2025</saleDate>
        <amountOfSecuritiesSold>10326</amountOfSecuritiesSold>
        <grossProceeds>3924.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/16/2025</saleDate>
        <amountOfSecuritiesSold>61638</amountOfSecuritiesSold>
        <grossProceeds>20341.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/17/2025</saleDate>
        <amountOfSecuritiesSold>77090</amountOfSecuritiesSold>
        <grossProceeds>25440.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/22/2025</saleDate>
        <amountOfSecuritiesSold>78049</amountOfSecuritiesSold>
        <grossProceeds>26537.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/23/2025</saleDate>
        <amountOfSecuritiesSold>89328</amountOfSecuritiesSold>
        <grossProceeds>30372.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>04/24/2025</saleDate>
        <amountOfSecuritiesSold>68195</amountOfSecuritiesSold>
        <grossProceeds>21822.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>06/24/2025</saleDate>
        <amountOfSecuritiesSold>231600</amountOfSecuritiesSold>
        <grossProceeds>81060.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>06/25/2025</saleDate>
        <amountOfSecuritiesSold>138800</amountOfSecuritiesSold>
        <grossProceeds>45804.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>06/26/2025</saleDate>
        <amountOfSecuritiesSold>213257</amountOfSecuritiesSold>
        <grossProceeds>70374.81</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>06/27/2025</saleDate>
        <amountOfSecuritiesSold>11043</amountOfSecuritiesSold>
        <grossProceeds>3754.62</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>07/07/2025</saleDate>
        <amountOfSecuritiesSold>23960</amountOfSecuritiesSold>
        <grossProceeds>11500.80</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>07/08/2025</saleDate>
        <amountOfSecuritiesSold>50700</amountOfSecuritiesSold>
        <grossProceeds>21801.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>07/09/2025</saleDate>
        <amountOfSecuritiesSold>57106</amountOfSecuritiesSold>
        <grossProceeds>25126.64</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>OrbiMed Private Investments VII, LP</name>
          <address>
            <com:street1>601 Lexington Ave., 54th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10022</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>07/10/2025</saleDate>
        <amountOfSecuritiesSold>127234</amountOfSecuritiesSold>
        <grossProceeds>50893.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <remarks>OrbiMed Capital GP VII LLC is the general partner of OrbiMed Private Investments VII, LP. OrbiMed Advisors LLC is the managing member of OrbiMed Capital GP VII LLC. All sales of securities listed on this Form 144 reflect share amounts prior to the 1-for-20 reverse stock split that was effectuated by the Issuer on July 14, 2025.</remarks>
      <noticeSignature>
        <noticeDate>07/15/2025</noticeDate>
        <signature>/s/ Douglas Coon, Chief Compliance Officer, OrbiMed Advisors LLC, managing member of the general partner of OrbiMed Private Investments VII, LP</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 12101}]
text: 144
  0001055951
  XXXXXXXX
  LIVE
  0001787297
  Passage BIO, Inc.
  001-39231
  One Commerce Square
  2005 Market Street, 39th Floor
  Philadelphia
  PA
  19103
  267-866-0312
  OrbiMed Private Investments VII, LP
  Stockholder
  Common Stock
  Themis Trading LLC
  10 Town Square
  Suite 100
  Chatham
  NJ
  07928
  53293
  361859.47
  3120295
  07/15/2025
  Nasdaq Stock Market
  Common Stock
  03/03/2020
  IPO
  Issuer
  N
  53293
  03/03/2020
  N/A
  N
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/15/2025
  10326
  3924.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/16/2025
  61638
  20341.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/17/2025
  77090
  25440.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/22/2025
  78049
  26537.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/23/2025
  89328
  30372.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  04/24/2025
  68195
  21822.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  06/24/2025
  231600
  81060.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  06/25/2025
  138800
  45804.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  06/26/2025
  213257
  70374.81
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  06/27/2025
  11043
  3754.62
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  07/07/2025
  23960
  11500.80
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  07/08/2025
  50700
  21801.00
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  07/09/2025
  57106
  25126.64
  OrbiMed Private Investments VII, LP
  601 Lexington Ave., 54th Floor
  New York
  NY
  10022
  Common Stock
  07/10/2025
  127234
  50893.00
  OrbiMed Capital GP VII LLC is the general partner of OrbiMed Private Investments VII, LP. OrbiMed Advisors LLC is the managing member of OrbiMed Capital GP VII LLC. All sales of securities listed on this Form 144 reflect share amounts prior to the 1-for-20 reverse stock split that was effectuated by the Issuer on July 14, 2025.
  07/15/2025
  /s/ Douglas Coon, Chief Compliance Officer, OrbiMed Advisors LLC, managing member of the general partner of OrbiMed Private Investments VII, LP