Merck's 21-Valent Pneumococcal Conjugate Vaccine Shows Efficacy Across Various Serotypes

Image credit: Bernard Chantal | stock.adobe.com

Merck’s novel adult-specific 21-valent pneumococcal conjugate vaccine V116 demonstrated positive results in multiple clinical trials across all 21 serotypes covered by the vaccine, according to data presented at the 13th Meeting of the International Society of Pneumonia and Pneumococcal Diseases.¹ V116 includes eight serotypes that are not addressed by currently approved pneumococcal vaccines, including 15A, 15C, 16F, 23A, 23B, 24F, 31, and 35B. Those serotypes were responsible for approximately 30% of invasive pneumococcal disease in individuals aged 65 years and older.²

Pre-pandemic 2019 data from the CDC indicate that the 21 serotypes covered by the V116 vaccine are responsible for 85% of invasive pneumococcal disease in adults 65 years of age and older.

“Invasive pneumococcal disease and pneumococcal pneumonia can cause serious illness, especially in older adults and those with immunocompromising conditions,” Walter Orenstein, MD, professor emeritus of medicine, epidemiology, global health and pediatrics at Emory University and member of Merck’s Scientific Advisory Committee, said in a press release. “These positive data demonstrate the potential for V116 to address an unmet need in adult pneumococcal disease prevention.”¹

There are more than 100 different serotypes of pneumococcal bacteria that may affect adults differently than children.² Those with a greater risk of infection include older adults and patients with certain chronic or immunocompromising health conditions, such as heart disease, lung disease, and liver disease. Mortality from invasive pneumococcal disease is highest among those aged 50 years and older.²

The positive results from these Phase III clinical trials include the pivotal STRIDE-3 (NCT05425732), STRIDE-4 (NCT05464420), STRIDE-5 (NCT05526716), STRIDE-6 (NCT05420961), STRIDE-7 (NCT05393037), and STRIDE-9 (NCT05633992) trials.

Investigators found that V116 was immunogenic for all 21 serotypes covered by the vaccine across several adult populations, including individuals who were pneumococcal vaccine-naïve, individuals who were pneumococcal vaccine-experienced, and individuals with an elevated risk of pneumococcal disease, including patients with HIV. Further, V116 produced greater immune responses than the comparators evaluated in the STRIDE trials for the serotypes unique to V116.

Among pneumococcal vaccine-naïve individuals aged 50 years and older in a subgroup of STRIDE-3, the vaccine was immunogenic across all 21 serotypes in the age groups of 50–64 years, 65–74 years, and 75–84 years.¹

Among pneumococcal vaccine-experienced adults aged 50 years and older in the STRIDE-6 trial, V116 produced immune responses that were comparable for the serotypes shared with the pneumococcal 15-valent conjugate vaccine (PCV15) and pneumococcal vaccine, polyvalent (23-valent [PPSV23]), as well as greater immune responses for the serotypes covered by V116 only, regardless of prior administration of a pneumococcal vaccine or the duration since it was administered.¹

In the STRIDE-7 trial, patients with HIV aged 18 years and older administered V116 experienced immune responses that were comparable to PCV15 and PPSV23 across all 13 shared serotypes, as well as greater immune responses for the eight serotypes covered by V116 only. In terms of safety, V116 showed a profile that was comparable to the studied comparative vaccines, including the pneumococcal 20-valent conjugate vaccine, PCV15, and PPSV23.

In December 2023, the FDA granted priority review to a biologics license application for V116, as a single dose for the prevention of invasive pneumococcal disease and pneumococcal pneumonia in adults. The BLA was given a Prescription Drug User Fee Act (PDUFA) date of June 17, 2024.²

“The extensive data presented this week reaffirm our confidence in the potential clinical value V116 could provide to a range of adult populations,” Eliav Barr, MD, Merck Research Laboratories senior vice president, head of global clinical development, and chief medical officer, said in a press release. “We are encouraged by the results of these studies showing that V116 has generated immune responses to the serotypes responsible for the majority of adult invasive pneumococcal disease.”¹

References

1. Merck Announces Positive Data on V116, an Investigational, 21-Valent Pneumococcal Conjugate Vaccine Specifically Designed for Adults, Demonstrated Immune Responses in Adults. Merck. News release. March 19, 2024. Accessed March 19, 2024. https://www.merck.com/news/merck-announces-positive-data-on-v116-an-investigational-21-valent-pneumococcal-conjugate-vaccine-specifically-designed-for-adults-demonstrated-immune-responses-in-adults/

2. FDA Grants Priority Review to Merck’s New Biologics License Application for V116, an Investigational, 21-valent Pneumococcal Conjugate Vaccine Specifically Designed to Protect Adults. Merck. News release. December 19, 2023. Accessed March 19, 2024. https://www.merck.com/news/fda-grants-priority-review-to-mercks-new-biologics-license-application-for-v116-an-investigational-21-valent-pneumococcal-conjugate-vaccine-specifically-designed-to-protect-adults/