VAX-31, an innovative investigational 31-valent pneumococcal conjugate vaccine (PCV) from Vaxcyte, has secured clearance for its Investigational New Drug (IND) application from the FDA for use in infants—a significant milestone reported by Vaxcyte on November 12, 2024. This vaccine aims to combat invasive pneumococcal disease (IPD), which poses a serious health risk across multiple age groups.
Designed to protect both infants and adults, VAX-31 has the potential to address approximately 94% of IPD cases among children under five years in the United States. Following this achievement, Vaxcyte intends to launch a phase 2 clinical trial focusing on infants, which will be a randomized, double-blind, active-controlled, dose-finding study anticipated to commence by the end of January 2025.
The proposed clinical trial will encompass a primary immunization series consisting of three doses administered at 2, 4, and 6 months of age, followed by a booster shot given between 12 to 15 months. Vaxcyte has set expectations for topline data regarding safety, tolerability, and immunogenicity to be released by mid-2026, with additional findings from the booster dose expected about nine months thereafter.
The FDA’s clearance for the IND application in infants was bolstered by compelling safety, tolerability, and immunogenicity data obtained from earlier phase 1/2 studies of VAX-31 conducted in an adult population. This promising vaccine is engineered to provide defense against both currently circulating and historically significant serotypes, with the capacity to cover approximately 86% of acute otitis media cases in children under five in the U.S.
Data from the phase 1/2 adult study, which included results from 1,015 healthy adults aged 50 and older, was released on September 3, 2024. According to Vaxcyte, the vaccine was found to be well tolerated and exhibited a favorable safety profile across all dosage levels during the six-month evaluation period. “At the middle and high doses, VAX-31 met or exceeded the OPA response non-inferiority criteria for all 20 serotypes common with PCV20,” Vaxcyte noted in their announcement.
Vaxcyte reports that approximately 300,000 children under the age of five succumb to infections caused by Streptococcus pneumoniae globally each year, marking it as the leading cause of vaccine-preventable deaths in this vulnerable demographic. Vaccination is highly recommended by the Centers for Disease Control and Prevention (CDC) for all children younger than five years, along with those aged 5 to 18 years who have underlying risk conditions.
In a statement reflecting on the progress of VAX-31, Jim Wassil, executive vice president and CEO of Vaxcyte, expressed pride in the significant strides made, particularly in light of the recent IND clearance for infants and the Breakthrough Therapy designation for adult applications. “The body of positive evidence generated by the VAX-31 and VAX-24 adult studies validates the potential of our site-specific, carrier-sparing platform to deliver best-in-class, broad-spectrum PCVs designed to provide protection against both currently circulating and historically prevalent serotypes while raising the bar for immunogenicity,” Wassil stated.
References:
1. Vaxcyte provides positive regulatory updates on VAX-31 pediatric and adult programs. Vaxcyte Inc. Press release. November 12, 2024. Accessed November 12, 2024. https://investors.vaxcyte.com/news-releases/news-release-details/vaxcyte-provides-positive-regulatory-updates-vax-31-pediatric
2. Vaxcyte Reports Positive Topline Data from Phase 1/2 Study of VAX-31, its 31-Valent Pneumococcal Conjugate Vaccine Candidate, in Adults Aged 50 and Older. Press release. September 3, 2024. Accessed November 12, 2024. https://investors.vaxcyte.com/news-releases/news-release-details/vaxcyte-reports-positive-topline-data-phase-12-study-vax-31-its
3. Pneumococcal vaccination. CDC. Updated October 26, 2024.
**Interview with Dr. Emily Chen, Chief Medical Officer at Vaxcyte**
**Editor:** Thank you for joining us today, Dr. Chen. Vaxcyte recently announced the FDA’s clearance for your investigational vaccine, VAX-31, targeting invasive pneumococcal disease in infants. How significant is this milestone for Vaxcyte and public health?
**Dr. Chen:** Thank you for having me. Securing the FDA’s green light for VAX-31 is indeed a pivotal moment for us and a significant advancement in public health. This vaccine has the potential to protect infants from invasive pneumococcal disease, a major cause of morbidity and mortality worldwide. We’re particularly excited about its capability to address approximately 94% of IPD cases in children under five in the U.S.
**Editor:** Can you explain what makes VAX-31 different from existing pneumococcal vaccines on the market?
**Dr. Chen:** Certainly. VAX-31 is a 31-valent conjugate vaccine, meaning it targets a broader range of pneumococcal serotypes than current vaccines. This innovative approach not only covers a significant portion of the acute otitis media cases in young children but also includes both currently circulating and historically significant strains of *Streptococcus pneumoniae*. Our data suggest a favorable safety profile, which is crucial when considering vaccines for infants.
**Editor:** What are the next steps following the IND clearance?
**Dr. Chen:** We are gearing up to launch a phase 2 clinical trial that will focus specifically on infants. This trial will be meticulously designed as a randomized, double-blind, active-controlled, dose-finding study. We’re planning to administer a primary immunization series consisting of three doses at 2, 4, and 6 months of age, followed by a booster shot between 12 to 15 months. We anticipate the trial to commence by the end of January 2025.
**Editor:** When can we expect to see results from this clinical trial?
**Dr. Chen:** We expect to release topline data regarding safety, tolerability, and immunogenicity by mid-2026. After that, additional findings from the booster dose should come about nine months later. All of this data is integral in helping us determine the vaccine’s effectiveness in the target population.
**Editor:** In light of the global impact of pneumococcal disease, how do you envision VAX-31 influencing childhood vaccination programs worldwide?
**Dr. Chen:** With around 300,000 children under five dying each year due to infections caused by *Streptococcus pneumoniae*, VAX-31 could have a profound impact on childhood vaccination programs globally. If the efficacy seen in our trials translates to real-world outcomes, it could lead to a significant decrease in both invasive diseases and ear infections, improving child health on a large scale. We believe that this vaccine could become a vital component of immunization schedules, not just in the U.S. but across many other regions facing the burden of pneumococcal disease.
**Editor:** Thank you for your insights, Dr. Chen. We look forward to following the progress of VAX-31 and its potential impact on public health.
**Dr. Chen:** Thank you for covering this important topic. We’re eager to share more updates as we move forward with the clinical trials.
