NCT06986239

Safety and Immunogenicity of PCV-LITE, a Low-dose of Pneumococcal Conjugate Vaccine With LiteVax Adjuvant

Safety, Tolerability and Immunogenicity of One Single Administration of PCV-LITE, a Novel Adjuvanted Pneumococcal Conjugate Vaccine Supplemented With LiteVax Adjuvant, in Young Healthy Participants

• Status: Not Yet Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 80 (estimated)
• Sponsor: LiteVax BV · Industry
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

Streptococcus pneumoniae is a common bacteria and major cause of serious infections like bloodstream infections, pneumonia, and meningitis. These infections are most common in children under 2 years old and adults over 65 years of age and dangerous for all age groups. Current vaccines, which contain parts of the bacteria, have significantly reduced the incidence of invasive pneumococcal disease (IPD). To broaden protection more serotypes are added to the vaccines over the years, which results in lower immune responses to the serotype-specific polysaccharides while a stronger vaccine is desired for older people and people with a weakened immune system. In addition, these complex vaccines are hardly affordable for the growing group of older adults in low- and middle-income countries (LMICs). To address these challenges, a new potent adjuvant called 'LiteVax Adjuvant' was developed. It has been shown to improve the efficacy of vaccines, even at low doses of antigen. A lower antigen dose reduces the costs of vaccines and promotes accessibility in LMICs. By testing a standard and a low dose of a commercial pneumococcal conjugate vaccine combined with LiteVax Adjuvant in healthy volunteers, we aim to determine whether the adjuvant enhances the immune response and if a lower vaccine dose is effective. At the same time, the safety of the vaccines is being investigated.

Detailed description

The objectives are to evaluate the safety and the immunogenicity of a single intramuscular (IM) injection of a standard dose of PCV20 and a low dose of PCV20 (1/5th) with or without 1 mg of LVA immunoadjuvant. This study is a randomized, Phase 1, single-center, observer-blind, active-controlled 4-arm study to evaluate the safety, tolerability, and immunogenicity of PCV-LITE, a novel adjuvanted pneumococcal conjugate vaccine. PCV-LITE consists of 1/5th-dose of PCV20 plus 1 mg of LVA (Cohort 2) and will be compared with 1/5th-dose of PCV20 without adjuvant (Cohort 1), a full dose of PCV20 plus 1 mg of LVA (Cohort 4) and a full dose of PCV20 without adjuvant (Cohort 3). The PCV20 will be the benchmark and the reference vaccine for the three study vaccines. Cohort 1: 1/5th-dose of PCV20 (reference vaccine diluted in saline), Cohort 2: 1/5th-dose of PCV20 plus 1 mg LVA (study vaccine; PCV-LITE), Cohort 3: full dose of PCV20 (reference vaccine), and Cohort 4: full dose of PCV20 plus 1 mg LVA (study vaccine). A total of 80 participants are planned to be randomized, 20 per cohort. Dose increase of PCV20 (1/5th-dose to a full dose) occurs in two stages (N=40 in each stage). Two consecutive sentinel groups per dose level of PCV20 (first 4 participants on Day 1 followed by 6 participants on Day 4 after an uneventful 72-hours safety follow-up) are implemented to minimize risk to the participants. Participants will randomly be assigned in each stage. A screening visit, a baseline/vaccination visit and 3 follow-up visits at Day 8, Day 29 and Day 181 will be performed. Sentinels will have an additional follow-up telephone contact at Day 4. The study duration for each participant will be up to 21 days of screening, and 180 ± 15 days of follow-up after vaccination. Participants will be healthy adults aged between 18 and 50 years (inclusive) who have had no laboratory confirmed S. pneumoniae infection in the 36 months prior to study vaccination and have not received an S. pneumoniae vaccination in the 36 months prior to study vaccination. Interventions: All participants will receive one IM vaccination with the reference or study vaccine. The study vaccine will be prepared by an unblinded pharmacist and administered by an unblinded vaccinator while the participant and other site staff remain blinded (observer-blind). Solicited local and systemic AEs will be recorded in an electronic diary (eDiary) for 14 days after vaccination. The study team will closely monitor the eDiary during the 14-day follow-up period. At Day 15, the Investigator will review the data in the eDiary to determine whether an additional visit is required. If so, the participant should visit the site within 3 days. Unsolicited AEs will be monitored for 28 days after vaccination. SAEs, pIMDs and AESIs will be assessed for 180 days after vaccination. Blood samples (± 12 mL) will be collected from all participants at screening for eligibility evaluation and to examine haematology and biochemistry to check health status. Blood samples will be collected also at the other visits (maximal 20 mL/Visit, 4 visits). In order to evaluate whether the vaccines induce antibodies in the mucosa, mucosal nose swab samples of Mucosal Lining Fluid (MLF) will be collected from all participants at Visit 1/Day 1 and Visit 3/Day 29. The samples will be processed by a local lab (labelled, listed, and frozen) and analyzed by an external laboratory following qualified standard procedures.

Conditions

• Vaccine Reaction

Interventions

Type	Name	Description
BIOLOGICAL	PCV-LITE	Fractional dose of pneumococcal polysaccharide conjugate vaccine without LiteVax Adjuvant (LVA)
BIOLOGICAL	PCV-LITE+LVA	Fractional dose of pneumococcal polysaccharide conjugate vaccine with 1 mg of LiteVax Adjuvant (LVA)
BIOLOGICAL	PCV20	Standard (full) dose of pneumococcal polysaccharide conjugate vaccine without LiteVax Adjuvant (LVA)
BIOLOGICAL	PCV20+LVA	Standard (full) dose of pneumococcal polysaccharide conjugate vaccine with LiteVax Adjuvant (LVA)

Timeline

• Start date: 2025-07-01
• Primary completion: 2026-04-01
• Completion: 2026-07-01
• First posted: 2025-05-22
• Last updated: 2025-05-22