<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT04490499</url>
  </required_header>
  <id_info>
    <org_study_id>V419-013</org_study_id>
    <secondary_id>V419-013</secondary_id>
    <secondary_id>2020-000126-26</secondary_id>
    <nct_id>NCT04490499</nct_id>
  </id_info>
  <brief_title>A Hepatitis B Vaccine Challenge Study After Previous Vaxelis® Vaccination (V419-013)</brief_title>
  <official_title>A Hepatitis B Vaccine Challenge Study to Demonstrate the Durability of Protection Against Hepatitis B Virus Infection in Healthy Children Vaccinated Approximately 9 Years Previously With a 2- or 3-Dose Infant Series and Toddler Dose of Vaxelis®</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Merck Sharp &amp; Dohme LLC</agency>
      <agency_class>Industry</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Merck Sharp &amp; Dohme LLC</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>Yes</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
    <is_us_export>Yes</is_us_export>
  </oversight_info>
  <brief_summary>
    <textblock>
      The purpose of this study is to demonstrate the durability of protection against hepatitis B&#xD;
      virus (HBV) infection approximately 8-9 years after vaccination with Vaxelis®. This is an&#xD;
      estimation study, and no formal hypothesis testing was performed.&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">September 2, 2020</start_date>
  <completion_date type="Actual">December 29, 2020</completion_date>
  <primary_completion_date type="Actual">December 29, 2020</primary_completion_date>
  <phase>Phase 3</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Prevention</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™</measure>
    <time_frame>Day 30</time_frame>
    <description>Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen</measure>
    <time_frame>Day 1 and Day 30</time_frame>
    <description>Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Actual">207</enrollment>
  <condition>Hepatitis B</condition>
  <arm_group>
    <arm_group_label>HBVAXPRO™</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who will receive a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
  </arm_group>
  <intervention>
    <intervention_type>Biological</intervention_type>
    <intervention_name>HBVAXPRO™</intervention_name>
    <description>Single 0.5 mL intramuscular dose</description>
    <arm_group_label>HBVAXPRO™</arm_group_label>
    <other_name>Hepatitis B virus (HBV) vaccine; V232</other_name>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Is healthy (based on a review of medical history and targeted physical examination)&#xD;
             based on the clinical judgment of the investigator.&#xD;
&#xD;
          -  Has participated in Protocol V419-007 and received a 3 + 1 Vaxelis® schedule or&#xD;
             participated in Protocol V419-008 and received a 2 + 1 Vaxelis® schedule.&#xD;
&#xD;
          -  The participant (or legally acceptable representative if applicable) provides written&#xD;
             informed consent/assent for the study.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Has a history of diagnosis (clinical, serological, or microbiological) of HBV&#xD;
             infection.&#xD;
&#xD;
          -  Has a known or suspected impairment of immunological function (e.g., human&#xD;
             immunodeficiency virus (HIV), splenectomy).&#xD;
&#xD;
          -  Has a known hypersensitivity to any component of the study vaccine.&#xD;
&#xD;
          -  Has a known or suspected blood dyscrasias, leukemia, lymphomas of any type or other&#xD;
             malignant neoplasms affecting the haematopoietic and lymphatic system.&#xD;
&#xD;
          -  Has a bleeding disorder contraindicating intramuscular vaccinations.&#xD;
&#xD;
          -  Has received any hepatitis B vaccine after participation in Protocol V419-007 or&#xD;
             V419-008.&#xD;
&#xD;
          -  Is or has an immediate family member (e.g., spouse, parent/legal guardian, sibling, or&#xD;
             child) who is investigational site or Sponsor staff directly involved with this study.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>8 Years</minimum_age>
    <maximum_age>10 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Medical Director</last_name>
    <role>Study Director</role>
    <affiliation>Merck Sharp &amp; Dohme LLC</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Tampereen yliopisto Kokkolan rokotetutkimusklinikka ( Site 0009)</name>
      <address>
        <city>Kokkola</city>
        <state>Mellersta Osterbotten</state>
        <zip>67100</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto - Tampereen rokotetutkimusklinikka ( Site 0001)</name>
      <address>
        <city>Tampere</city>
        <state>Pirkanmaa</state>
        <zip>33100</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Seinajoki Vaccine Research Center ( Site 0010)</name>
      <address>
        <city>Seinajoki</city>
        <state>Pohjanmaa</state>
        <zip>60100</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto Oulun rokotetutkimusklinikka ( Site 0004)</name>
      <address>
        <city>Oulu</city>
        <state>Pohjois-Pohjanmaa</state>
        <zip>90220</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Porin rokotetutkimusklinikka ( Site 0008)</name>
      <address>
        <city>Pori</city>
        <state>Satakunta</state>
        <zip>28100</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto Espoon rokotetutkimusklinikka ( Site 0007)</name>
      <address>
        <city>Espoo</city>
        <state>Uusimaa</state>
        <zip>02230</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto Etelä-Helsingin rokotetutkimusklinikka ( Site 0005)</name>
      <address>
        <city>Helsinki</city>
        <state>Uusimaa</state>
        <zip>00100</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Ita-Helsingin Rokotetutkimuskeskus ( Site 0006)</name>
      <address>
        <city>Helsinki</city>
        <state>Uusimaa</state>
        <zip>00930</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto Järvenpään rokotetutkimusklinikka ( Site 0003)</name>
      <address>
        <city>Jarvenpaa</city>
        <state>Uusimaa</state>
        <zip>04400</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Tampereen yliopisto Turun rokotetutkimusklinikka ( Site 0002)</name>
      <address>
        <city>Turku</city>
        <state>Varsinais-Suomi</state>
        <zip>20520</zip>
        <country>Finland</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Finland</country>
  </location_countries>
  <results_reference>
    <citation>Ahonen A, Zhang Y, Marcek T, Lumley J, Johnson DR, Guris D, Wilck MB. Demonstration of durable hepatitis B immune memory in children vaccinated with a DTaP5-IPV-HepB-Hib infant-toddler series 7 to 8 years previously. Hum Vaccin Immunother. 2022 Nov 30;18(5):2073747. doi: 10.1080/21645515.2022.2073747. Epub 2022 Jun 2.</citation>
    <PMID>35653552</PMID>
  </results_reference>
  <verification_date>July 2022</verification_date>
  <study_first_submitted>July 28, 2020</study_first_submitted>
  <study_first_submitted_qc>July 28, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">July 29, 2020</study_first_posted>
  <results_first_submitted>August 10, 2021</results_first_submitted>
  <results_first_submitted_qc>August 10, 2021</results_first_submitted_qc>
  <results_first_posted type="Actual">September 5, 2021</results_first_posted>
  <last_update_submitted>July 20, 2022</last_update_submitted>
  <last_update_submitted_qc>July 20, 2022</last_update_submitted_qc>
  <last_update_posted type="Actual">July 27, 2022</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Hepatitis A</mesh_term>
    <mesh_term>Hepatitis B</mesh_term>
    <mesh_term>Hepatitis</mesh_term>
  </condition_browse>
  <intervention_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Vaccines</mesh_term>
  </intervention_browse>
  <patient_data>
    <sharing_ipd>Yes</sharing_ipd>
    <ipd_description>http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf</ipd_description>
    <ipd_url>http://engagezone.msd.com/ds_documentation.php</ipd_url>
  </patient_data>
  <provided_document_section>
    <provided_document>
      <document_type>Study Protocol and Statistical Analysis Plan</document_type>
      <document_has_protocol>Yes</document_has_protocol>
      <document_has_icf>No</document_has_icf>
      <document_has_sap>Yes</document_has_sap>
      <document_date>April 27, 2020</document_date>
      <document_url>https://ClinicalTrials.gov/ProvidedDocs/99/NCT04490499/Prot_SAP_000.pdf</document_url>
    </provided_document>
  </provided_document_section>

  <clinical_results>

    <participant_flow>
      <pre_assignment_details>Approximately 200 planned to be enrolled and 207 were enrolled.</pre_assignment_details>
      <group_list>
        <group group_id="P1">
          <title>HBVAXPRO™</title>
          <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
        </group>
      </group_list>
      <period_list>
        <period>
          <title>Overall Study</title>
          <milestone_list>
            <milestone>
              <title>STARTED</title>
              <participants_list>
                <participants group_id="P1" count="207"/>
              </participants_list>
            </milestone>
            <milestone>
              <title>Vaccinated</title>
              <participants_list>
                <participants group_id="P1" count="205"/>
              </participants_list>
            </milestone>
            <milestone>
              <title>COMPLETED</title>
              <participants_list>
                <participants group_id="P1" count="205"/>
              </participants_list>
            </milestone>
            <milestone>
              <title>NOT COMPLETED</title>
              <participants_list>
                <participants group_id="P1" count="2"/>
              </participants_list>
            </milestone>
          </milestone_list>
          <drop_withdraw_reason_list>
            <drop_withdraw_reason>
              <title>Withdrawal by Subject</title>
              <participants_list>
                <participants group_id="P1" count="2"/>
              </participants_list>
            </drop_withdraw_reason>
          </drop_withdraw_reason_list>
        </period>
      </period_list>
    </participant_flow>

    <baseline>
      <group_list>
        <group group_id="B1">
          <title>HBVAXPRO™</title>
          <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
        </group>
      </group_list>
      <analyzed_list>
        <analyzed>
          <units>Participants</units>
          <scope>Overall</scope>
          <count_list>
            <count group_id="B1" value="207"/>
          </count_list>
        </analyzed>
      </analyzed_list>
      <measure_list>
        <measure>
          <title>Age</title>
          <units>years</units>
          <param>Mean</param>
          <dispersion>Standard Deviation</dispersion>
          <class_list>
            <class>
              <category_list>
                <category>
                  <measurement_list>
                    <measurement group_id="B1" value="8.4" spread="0.5" lower_limit="0.5"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
        <measure>
          <title>Sex: Female, Male</title>
          <units>Participants</units>
          <param>Count of Participants</param>
          <class_list>
            <class>
              <category_list>
                <category>
                  <title>Female</title>
                  <measurement_list>
                    <measurement group_id="B1" value="97"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Male</title>
                  <measurement_list>
                    <measurement group_id="B1" value="110"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
        <measure>
          <title>Ethnicity (NIH/OMB)</title>
          <units>Participants</units>
          <param>Count of Participants</param>
          <class_list>
            <class>
              <category_list>
                <category>
                  <title>Hispanic or Latino</title>
                  <measurement_list>
                    <measurement group_id="B1" value="2"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Not Hispanic or Latino</title>
                  <measurement_list>
                    <measurement group_id="B1" value="205"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Unknown or Not Reported</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
        <measure>
          <title>Race (NIH/OMB)</title>
          <units>Participants</units>
          <param>Count of Participants</param>
          <class_list>
            <class>
              <category_list>
                <category>
                  <title>American Indian or Alaska Native</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Asian</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Native Hawaiian or Other Pacific Islander</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Black or African American</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
                <category>
                  <title>White</title>
                  <measurement_list>
                    <measurement group_id="B1" value="205"/>
                  </measurement_list>
                </category>
                <category>
                  <title>More than one race</title>
                  <measurement_list>
                    <measurement group_id="B1" value="2"/>
                  </measurement_list>
                </category>
                <category>
                  <title>Unknown or Not Reported</title>
                  <measurement_list>
                    <measurement group_id="B1" value="0"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
        <measure>
          <title>Region of Enrollment</title>
          <units>Participants</units>
          <param>Count of Participants</param>
          <class_list>
            <class>
              <title>Finland</title>
              <category_list>
                <category>
                  <measurement_list>
                    <measurement group_id="B1" value="207"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
      </measure_list>
    </baseline>

    <outcome_list>
      <outcome>
        <type>Primary</type>
        <title>Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™</title>
        <description>Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.</description>
        <time_frame>Day 30</time_frame>
        <population>The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.</population>
        <group_list>
          <group group_id="O1">
            <title>HBVAXPRO™</title>
            <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
          </group>
        </group_list>
        <measure>
          <title>Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™</title>
          <description>Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.</description>
          <population>The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.</population>
          <units>Percentage of Participants</units>
          <param>Number</param>
          <dispersion>95% Confidence Interval</dispersion>
          <analyzed_list>
            <analyzed>
              <units>Participants</units>
              <scope>Measure</scope>
              <count_list>
                <count group_id="O1" value="202"/>
              </count_list>
            </analyzed>
          </analyzed_list>
          <class_list>
            <class>
              <category_list>
                <category>
                  <measurement_list>
                    <measurement group_id="O1" value="99.5" spread="97.3" lower_limit="97.3" upper_limit="100.0"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
      </outcome>
      <outcome>
        <type>Secondary</type>
        <title>Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen</title>
        <description>Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.</description>
        <time_frame>Day 1 and Day 30</time_frame>
        <population>The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.</population>
        <group_list>
          <group group_id="O1">
            <title>HBVAXPRO™</title>
            <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
          </group>
        </group_list>
        <measure>
          <title>Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen</title>
          <description>Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.</description>
          <population>The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.</population>
          <units>mIU/mL</units>
          <param>Geometric Mean</param>
          <dispersion>95% Confidence Interval</dispersion>
          <analyzed_list>
            <analyzed>
              <units>Participants</units>
              <scope>Measure</scope>
              <count_list>
                <count group_id="O1" value="205"/>
              </count_list>
            </analyzed>
          </analyzed_list>
          <class_list>
            <class>
              <title>Day 1 Pre-challenge</title>
              <analyzed_list>
                <analyzed>
                  <units>Participants</units>
                  <scope>Class</scope>
                  <count_list>
                    <count group_id="O1" value="205"/>
                  </count_list>
                </analyzed>
              </analyzed_list>
              <category_list>
                <category>
                  <measurement_list>
                    <measurement group_id="O1" value="9.63" lower_limit="7.88" upper_limit="11.76"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
            <class>
              <title>Day 30 Post-challenge</title>
              <analyzed_list>
                <analyzed>
                  <units>Participants</units>
                  <scope>Class</scope>
                  <count_list>
                    <count group_id="O1" value="202"/>
                  </count_list>
                </analyzed>
              </analyzed_list>
              <category_list>
                <category>
                  <measurement_list>
                    <measurement group_id="O1" value="685.84" lower_limit="605.67" upper_limit="776.63"/>
                  </measurement_list>
                </category>
              </category_list>
            </class>
          </class_list>
        </measure>
      </outcome>
    </outcome_list>

    <reported_events>
      <time_frame>Up to Day 30</time_frame>
      <desc>The analysis population included all participants who received study vaccine and had safety follow-up data after the vaccination. The all-cause mortality analysis population included all enrolled participants. Per protocol, reported non-serious adverse events only include non-serious adverse events that lead to study discontinuation.</desc>
      <group_list>
        <group group_id="E1">
          <title>HBVAXPRO™</title>
          <description>Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).</description>
        </group>
      </group_list>
      <serious_events>
        <category_list>
          <category>
            <title>Total</title>
            <event_list>
              <event>
                <sub_title>Total, all-cause mortality</sub_title>
                <counts group_id="E1" subjects_affected="0" subjects_at_risk="207"/>
              </event>
              <event>
                <sub_title>Total, serious adverse events</sub_title>
                <counts group_id="E1" subjects_affected="0" subjects_at_risk="205"/>
              </event>
            </event_list>
          </category>
        </category_list>
      </serious_events>
      <other_events>
        <frequency_threshold>5</frequency_threshold>
        <category_list>
          <category>
            <title>Total</title>
            <event_list>
              <event>
                <sub_title>Total, other adverse events</sub_title>
                <counts group_id="E1" subjects_affected="0" subjects_at_risk="205"/>
              </event>
            </event_list>
          </category>
        </category_list>
      </other_events>
    </reported_events>

    <certain_agreements>
      <pi_employee>Principal Investigators are NOT employed by the organization sponsoring the study.</pi_employee>
      <restrictive_agreement>If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. This allows the Sponsor to protect proprietary information and to provide comments.</restrictive_agreement>
    </certain_agreements>
    <point_of_contact>
      <name_or_title>Senior Vice President, Global Clinical Development</name_or_title>
      <organization>Merck Sharp &amp; Dohme Corp.</organization>
      <phone>1-800-672-6372</phone>
      <email>ClinicalTrialsDisclosure@merck.com</email>
    </point_of_contact>
  </clinical_results>
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT04490499
org study id: V419-013
secondary id: V419-013
secondary id: 2020-000126-26
nct id: NCT04490499
lead sponsor: 
has dmc: No
is fda regulated drug: Yes
is fda regulated device: No
is us export: Yes
The purpose of this study is to demonstrate the durability of protection against hepatitis B
      virus (HBV) infection approximately 8-9 years after vaccination with Vaxelis®. This is an
      estimation study, and no formal hypothesis testing was performed.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Prevention
masking: None (Open Label)
measure: Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™
time frame: Day 30
description: Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.
measure: Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen
time frame: Day 1 and Day 30
description: Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.
arm group label: HBVAXPRO™
arm group type: Experimental
description: Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who will receive a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
intervention type: Biological
intervention name: HBVAXPRO™
description: Single 0.5 mL intramuscular dose
arm group label: HBVAXPRO™
other name: Hepatitis B virus (HBV) vaccine; V232
criteria: 
gender: All
minimum age: 8 Years
maximum age: 10 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Medical Director
role: Study Director
affiliation: Merck Sharp & Dohme LLC
facility: 
facility: 
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country: Finland
citation: Ahonen A, Zhang Y, Marcek T, Lumley J, Johnson DR, Guris D, Wilck MB. Demonstration of durable hepatitis B immune memory in children vaccinated with a DTaP5-IPV-HepB-Hib infant-toddler series 7 to 8 years previously. Hum Vaccin Immunother. 2022 Nov 30;18(5):2073747. doi: 10.1080/21645515.2022.2073747. Epub 2022 Jun 2.
PMID: 35653552
responsible party type: Sponsor
mesh term: Hepatitis A
mesh term: Hepatitis B
mesh term: Hepatitis
mesh term: Vaccines
sharing ipd: Yes
ipd description: http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf
ipd url: http://engagezone.msd.com/ds_documentation.php
provided document: 
participant flow: 
baseline: 
outcome list: 
reported events: 
certain agreements: 
point of contact: 