MnB Vaccine Induces Immunogenicity Among Young People
NEW ORLEANS, LA—The meningococcal Serogroup B vaccine MenB-FHbp (Bivalent rLP2086) induces immunogenicity in young people age 10–18, according to findings from a confirmatory pivotal Phase 3 clinical trial reported at IDWeek 2016.
“As in the global study, MenB-FHbp elicited robust and broad immune responses in U.S. adolescents after 2 and 3 doses,” reported Judith Absalon, MD, MPH, of Pfizer Vaccine Research, Pearl River, NY, and coauthors, in a poster presentation. “Vaccine lots were similar.”
The U.S. has seen several MnB outbreaks among college students. MenB-FHbp (Trumenba) targets MnB factor H binding proteins (fHBP). In October 2014, it became the first Food and Drug Administration (FDA)-approved MnB disease-preventing vaccine for use with people age 10–25 years. The Advisory Committee on Immunization Practices (ACIP) recommends that a vaccine series of either licensed MnB vaccine be considered for all adolescents and young adults aged 16–23 years (preferred 16–18 years). For high-risk patients aged ≥10 years, the ACIP also recommends vaccination with a MnB vaccine.
FDA approval was granted under an accelerated review process, based on prior Phase 2 study surrogate data demonstrating that the vaccine induced bacterial antibodies against different strains of MnB.
To confirm those findings among young people in the U.S., the authors randomized a total of 1,359 healthy participants age 10–<19 years to receive 1 of 3 lots of MenB-FHbp at 0 (baseline), 2 and 6 months, or a hepatitis A virus vaccine at 0 and 6 months, with saline at 2 months. To assess immunogenicity, serum bactericidal assays using human complement (hsBAs) were employed with 4 primary MnB test strains that express vaccine-heterologous fHBP variants.
Primary immunogenicity endpoints included proportion of study participants exhibiting a ≥4-fold increase in hSBA titers from baseline for each test strain, and the proportion of participants exhibiting hSBA titers above or equal to the lower limit of quantification for all 4 test strains combined after the third dose (“composite response”), the authors reported.
“Eighty-two percent to 92% of participants had ≥4-fold rise in hSBA titers from baseline to 1 month after dose 3 against each primary strain [and] 85.7% achieved a composite response after dose 3.” the authors reported. “Corresponding results after dose 2 were 55.5–87.3% and 50.5%, respectively. The hSBA GMTs were similar for all 3 vaccine lots (GMT ratio range: 0.87–1.04).”
“Lower confidence interval threshold criteria were achieved for U.S. subjects; thus coprimary endpoints were met,” they concluded.