Safety, Tolerability, and Immunogenicity Study of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Older Adults

• ClinicalTrials.gov Identifier: NCT05297578
• Recruitment Status: Completed
• First Posted: March 28, 2022
• Results First Posted: April 16, 2024
• Last Update Posted: April 16, 2024
• Sponsor: Vaxcyte, Inc.
• Information provided by (Responsible Party): Vaxcyte, Inc.

Tracking Information

• First Submitted Date: March 17, 2022
• First Posted Date: March 28, 2022
• Results First Submitted Date: February 13, 2024
• Results First Posted Date: April 16, 2024
• Last Update Posted Date: April 16, 2024
• Actual Study Start Date: June 15, 2022
• Actual Primary Completion Date: February 15, 2023 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: February 13, 2024)

• Percentage of Participants Reporting Solicited Local Reactions Within 7 Days After Vaccination [ Time Frame: 7 days after vaccination ]
  Solicited local reactions included redness/erythema, swelling/induration, and pain at injection site
• Percentage of Participants Reporting Solicited Systemic Events Within 7 Days After Vaccination [ Time Frame: 7 days after vaccination ]
  Solicited systemic reactions include fever, headache, fatigue, muscle pain, and joint pain within 7 days of vaccination
• Percentage of Subjects Reporting Unsolicited Adverse Events Within 1 Month After Vaccination [ Time Frame: 1 month after vaccination ]
  Percentage of participants with at least one Treatment Emergent Adverse Event (unsolicited AEs and SAEs)
• Percentage of Participants Reporting SAEs and New Onset of Chronic Illnesses (NOCIs) [ Time Frame: 6 months after vaccination ]
  Percentage of participants with serious adverse events (SAEs) and new onset of chronic illness (NOCIs)

Original Primary Outcome Measures (submitted: March 17, 2022)

• Percentage of participants reporting solicited local reactions within 7 days after vaccination [ Time Frame: 7 days after vaccination ]
  Solicited local reactions included redness/erythema, swelling/induration, and pain at injection site
• Percentage of participants reporting solicited systemic events within 7 days after vaccination [ Time Frame: 7 days after vaccination ]
  Solicited systemic reactions include fever, headache, fatigue, muscle pain, and joint pain
• Percentage of subjects reporting unsolicited adverse events within 1 month after vaccination [ Time Frame: 1 month after vaccination ]
  Percentage of participants with adverse events and serious adverse events (SAEs)
• Percentage of participants reporting SAEs and new onset of chronic illnesses (NOCIs) [ Time Frame: 6 months after vaccination ]
  Percentage of participants with SAEs and NOCIs

Current Secondary Outcome Measures (submitted: March 25, 2024)

• VAX-24 Pneumococcal Serotype-specific Opsonophagocytic Assay (OPA) Geometric Mean Titer (GMTs) [ Time Frame: 1 month after vaccination ]
  The change from baseline to 1 month post-vaccination in the immune response directed against each of the 24 serotypes was evaluated by measuring serotype-specific functional antibody responses with an opsonophagocytic (OPA) assay that assesses the functional capacity of pneumococcal antibodies.
• 24 VAX-24 Pneumococcal Serotype-specific IgG Geometric Mean Concentration (GMCs) [ Time Frame: 1 month after vaccination ]
  The change from baseline to 1 month post-vaccination in the immune response directed against each of the 24 serotypes was evaluated by measuring IgG levels using an IgG multiplexed electrochemoluminescent assay (ECLA). Values below the lower limit of quantitation (LLOQ) were analyzed as 0.5*LLOQ. Values above the upper limit of quantitation (ULOQ) were analyzed as 1*ULOQ.

Original Secondary Outcome Measures (submitted: March 17, 2022)

• 24 VAX-24 Pneumococcal serotype-specific opsonophagocytic assay (OPA) geometric mean titer (GMTs) [ Time Frame: 1 month after vaccination ]
  Antibody geometric mean titers as measured by OPA for the 24 pneumococcal serotypes in VAX-24
• 24 VAX-24 Pneumococcal serotype-specific IgG geometric mean concentration (GMCs) [ Time Frame: 1 month after vaccination ]
  Antibody geometric mean concentrations as measured by IgG for the 24 pneumococcal serotypes in VAX-24

• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Safety, Tolerability, and Immunogenicity Study of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Older Adults
• Official Title: A Phase 2, Randomized, Observer-Blind, Dose-Finding, Controlled Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of a 24-Valent Pneumococcal Conjugate Vaccine (VAX-24) in Healthy Adults 65 Years and Older
• Brief Summary: The objective of the study is to evaluate the safety and tolerability of a single injection of VAX-24 at 3 dose levels compared to Prevnar 20™ (PCV20) in adults 65 years of age and older.
• Detailed Description: The objective of the study is to evaluate the safety and tolerability of a single injection of VAX-24 at 3 dose levels (Low: 1.1 mcg; Mid: 2.2 mcg; or Mixed: 2.2/4.4 mcg) compared to Prevnar 20™ (PCV20) in adults 65 years of age and older.
• Study Type: Interventional
• Study Phase: Phase 2

Study Design

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Masking Description:

Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) Triple (Participant, Investigator, Outcomes Assessor)

Primary Purpose: Prevention

• Condition: Pneumococcal Vaccines

Intervention

• Biological: 24-Valent Pneumococcal Conjugate Vaccine
  0.5 ml dose of VAX-24 will be administered into the deltoid muscle at Day 1
• Biological: Pneumococcal 20-valent Conjugate Vaccine
  0.5 ml dose of Prevnar 20 will be administered into the deltoid muscle at Day 1
  Other Name: Prevnar 20, PCV20

Study Arms

• Experimental: VAX-24 Low Dose
  Participants will receive a single dose of VAX-24 1.1 mcg administered as an intramuscular injection on Day 1.
  Intervention: Biological: 24-Valent Pneumococcal Conjugate Vaccine
• Experimental: VAX-24 Mid Dose
  Participants will receive a single dose of VAX-24 2.2 mcg administered as an intramuscular injection on Day 1.
  Intervention: Biological: 24-Valent Pneumococcal Conjugate Vaccine
• Experimental: VAX-24 Mixed Dose
  Participants will receive a single dose of VAX-24 2.2 mcg/4.4 mcg administered as an intramuscular injection on Day 1.
  Intervention: Biological: 24-Valent Pneumococcal Conjugate Vaccine
• Active Comparator: PCV20
  Participants will receive a single intramuscular injection of the standard dose of PCV20 on Day 1.
  Intervention: Biological: Pneumococcal 20-valent Conjugate Vaccine

• Publications *: Not Provided

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: September 12, 2022): 207
• Original Estimated Enrollment (submitted: March 17, 2022): 200
• Actual Study Completion Date: February 15, 2023
• Actual Primary Completion Date: February 15, 2023 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

• Male or female age 65 or older.
• Able and willing to complete the informed consent process.
• Available for clinical follow-up through the last study visit at 6 months after the study vaccination.
• In good general health as determined by medical history, vital signs, physical examination, and clinical judgment of the investigator. Preexisting medical conditions must be stable as defined by no change in treatment at least 6 weeks prior to study participation.
• Willing to have blood samples collected, stored indefinitely, and used for research purposes.
• Able to provide proof of identity to the satisfaction of the study staff completing the enrollment process.

Exclusion Criteria:

• Previous pneumococcal disease (either confirmed or by self-reporting).
• Previous receipt of a licensed or investigational pneumococcal vaccine.
• Receipt of any investigational study product within 30 days prior to enrollment into the study, currently participating in another interventional investigational study, or having plans to receive another investigational product(s) while on study.
• Planned or actual administration of any licensed vaccine during the period starting 30 days before enrollment into the study through Day 29.
• Physical examination indicating any clinically significant medical condition.
• Body Temperature > 38.0°C (> 100.4°F) or acute illness within 3 days prior to study vaccination (subject may be rescheduled).
• Previous or existing diagnosis of HIV, Hepatitis B or Hepatitis C.
• History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis.
• Bleeding disorder diagnosed by a doctor (eg, factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with intramuscular injections or blood draws.
• Any other chronic or clinically significant medical condition that, in the opinion of the investigator, would jeopardize the safety or rights of the subject or confound evaluation of the study vaccine.
• Any medical, psychiatric, or social condition that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a subject's ability to give informed consent.
• Received blood or blood product (including Immune Globulin IV) within 90 days prior to enrollment into the study.
• Received systemic corticosteroids for ≥ 14 consecutive days and has not completed treatment ≤30 days prior to enrollment into the study.
• Receiving immunosuppressive therapy.
• History of malignancy ≤5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer.

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 65 Years and older (Older Adult)
• Accepts Healthy Volunteers: Yes
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: United States

Administrative Information

• NCT Number: NCT05297578
• Other Study ID Numbers: VAX24-102
• Has Data Monitoring Committee: Yes

U.S. FDA-regulated Product

• Studies a U.S. FDA-regulated Drug Product: Yes
• Studies a U.S. FDA-regulated Device Product: No

IPD Sharing Statement

• Plan to Share IPD: No

• Current Responsible Party: Vaxcyte, Inc.
• Original Responsible Party: Same as current
• Current Study Sponsor: Vaxcyte, Inc.
• Original Study Sponsor: Same as current
• Collaborators: Not Provided

Investigators

• Study Director: Clinical Development; Vaxcyte, Inc.

• PRS Account: Vaxcyte, Inc.
• Verification Date: March 2024