Merck's V116 Vaccine Shows Promising Results in Phase 3 Studies at ISPPD: Key Findings and Real-World Impact

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Merck's 21-valent pneumococcal vaccine, V116, exhibits strong immunogenicity and coverage in diverse adult populations against invasive pneumococcal disease and pneumococcal pneumonia. At the 13th Meeting of the International Society of Pneumonia and Pneumococcal Diseases (ISPPD) in Cape Town, South Africa, the pharmaceutical giant unveiled positive results from multiple Phase 3 studies.

The FDA granted V116 priority review with a Prescription Drug User Fee Act (PDUFA) of June 17, 2024.

V116, an investigational 21-valent pneumococcal conjugate vaccine explicitly designed for adults, showcased immunogenicity across the board. These Phase 3 trials demonstrated its effectiveness in a diverse range of adult populations, including those previously unvaccinated against pneumococcal diseases and individuals at higher risk, such as those with human immunodeficiency virus (HIV).

Merck also presented preliminary findings from the Pneumococcal Pneumonia Epidemiology, Urine Serotyping, and Mental Outcomes (PNEUMO) study conducted in the US. This real-world evidence study shed light on V116's tangible impact, showing that among 2,065 adults aged 50 and older hospitalized with community-acquired pneumonia, V116 covered approximately 84% of detected pneumococcal serotypes. Notably, a quarter of the identified serotypes were exclusively covered by V116, highlighting its unique efficacy profile.

Heather Platt, MD, distinguished scientist, Global Clinical Development for Vaccines, Merck

(Photo credit: Merck)

To understand the implications of these results, Infection Control Today^® (ICT^®) asked Heather Platt, MD, distinguished scientist, Global Clinical Development for Vaccines, Merck, to discuss the company’s pneumococcal vaccine development program and the potential impact of V116’s approval for patients and their doctors.

ICT: Could you elaborate on the significance of Merck’s positive Phase 3 data on V116, particularly its immunogenicity across adult populations and its potential impact on pneumococcal disease prevention?

Heather Platt, MD:

Across all the Phase 3 studies, V116 elicited an immune response to all 21 serotypes covered by the vaccine in a variety of adult populations, including among vaccine-naïve and vaccine-experienced adults, as well as those with chronic medical conditions that increase the risk of pneumococcal disease. Results also showed that in all STRIDE studies presented, V116 elicited higher immune responses than the comparator (PCV20, PCV15, and PPSV23) for the serotypes unique to V116.

• In the STRIDE-3 sub-group analysis, which evaluated adults aged 50 years and above who had not received pneumococcal vaccine before, all 21 serotypes were found to be immunogenic across all age groups studied (50 to 64, 65 to 74, and 75 years and above) at Day 30. This was determined by assessing the opsonophagocytic activity (OPA) geometric mean titers (GMTs) for each serotype. These findings support the potential clinical value V116 may provide to adults 50 and older.
• In STRIDE-6, which evaluated pneumococcal vaccine-experienced adults 50 years of age and older, V116 elicited comparable immune responses for the serotypes shared with PCV15 or PPSV23 and higher immune responses for the serotypes covered by V116 only, regardless of the previous pneumococcal vaccine received, as assessed by serotype-specific OPA GMTs at Day 30. Additionally, a sub-group analysis showed the V116 elicited comparable immune responses regardless of the time since the last pneumococcal vaccination (1–4 years, 5–9 years, or greater than 10 years). The findings from the STRIDE-6 main study and sub-group analysis support the potential clinical value V116 may provide to adults 50 years of age and older, regardless of the prior pneumococcal received or the time since the last pneumococcal vaccination.
• In STRIDE-7 evaluating adults 18 years of age and older living with HIV, V116 elicited comparable immune responses to the regimen of PCV15+PPSV23 for all 13 shared serotypes and higher immune responses for the eight serotypes unique to V116, as assessed by serotype-specific OPA GMTs and Immunoglobulin G (IgG) geometric mean concentrations (GMCs) at Day 30. These findings support the potential clinical value that V116 may provide to adults with a high risk for invasive pneumococcal disease.

ICT: The real-world evidence study PNEUMO revealed that V116 exclusively covered a significant portion of detected serotypes. How does this finding contribute to understanding V116’s efficacy in preventing pneumococcal disease, especially considering its coverage compared to existing vaccines?

HP:

• The PNEUMO study evaluated adults 50 years of age and older hospitalized with community-acquired pneumonia. The results support that the serotypes in V116 account for the majority of pneumococcal disease (including invasive and non-invasive).
• Specifically, of the patients hospitalized with community-acquired pneumonia due to Streptococcus pneumoniae, approximately 84% were attributed to a serotype in V116. Of these, more than one-fourth of pneumococcal serotypes detected (~25%) were covered by V116 only and not covered by PCV15 or PCV20. These data are consistent with CDC surveillance data for invasive pneumococcal disease (IPD) from 2018 to 2021, which show that the eight serotypes covered by V116 and not by other licensed pneumococcal vaccines were responsible for approximately 30% of IPD in individuals 65 years and older.

ICT: Given the devastating impact of invasive pneumococcal disease, particularly in older adults and those with immunocompromising conditions, how does Merck envision V116 addressing these critical gaps in prevention, as indicated by the Phase 3 results and real-world evidence from the PNEUMO study?

HP:

• If approved, V116 will be the first vaccine specifically designed for adults by including the serotypes that cause the majority of invasive pneumococcal disease.
• We believe there is an opportunity for V116 to provide clinical value for adult patients (especially for older adults and those with risk conditions) who have yet to be vaccinated, as well as those who previously received a pneumococcal vaccine, due to the 8 unique serotypes for which V116 provides coverage.
• In the US alone, approximately 120 million pneumococcal vaccine-naïve and vaccine-experienced adults aged 50 and older may benefit from V116. Approximately half of these adults are in the 50 to 64 age group.
• Merck has a comprehensive strategy to advance options to help prevent invasive pneumococcal disease and pneumococcal pneumonia in all age groups, including adults. We remain focused on targeting the pneumococcal serotypes that pose the greatest risk of invasive pneumococcal disease for each population.