The Priority Review

Clinical trials

Booster of rMenB+OMV NZ gave primed participants 3.89 times the fHbp titer of naïve participants

In a 312-participant GlaxoSmithKline study aged 10 to 20 years, one booster dose in primed participants gave a fHbp hSBA titer ratio of 3.89 against the first dose in naïve participants at Day 31. The record now holds results for all four MenB indicator strains.

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Participants aged 10 to 20 years who were primed with rMenB+OMV NZ in the first 2 years of life had a geometric mean hSBA titer of 24.2 against the fHbp strain at Day 31 after one booster dose, against 6.2 in naïve participants after their first dose, a group GMT ratio of 3.89 (95% confidence interval 2.78 to 5.46), the ClinicalTrials.gov record shows. The GlaxoSmithKline Phase 3b study enrolled 312 participants, so this age group now has posted immune response and safety results for a booster dose after infant vaccination.

Primed against Naïve hSBA GMT ratio by MenB strain at Day 31 hSBA geometric mean titers, one booster dose in Primed and first dose in Naïve participants 0 5 10 15 20 25 Group GMT ratio, Primed against Naïve (95% confidence interval) fHbp GMT 24.2 and 6.2 2.78 to 5.46 3.89 NadA GMT 844.9 and 54.3 10.72 to 22.55 15.55 NHBA GMT 14.0 and 10.4 1.004 to 1.82 1.35 PorA GMT 10.0 and 5.7 1.25 to 2.50 1.77 The record sets the superiority criterion as a lower limit of the 2-sided 95% confidence interval of the ratio above 1. The ratios used ANCOVA with baseline, age and country as independent variables. From the trial registry record NCT06995430, results first posted November 6, 2026. The Priority Review.
Primed against Naïve hSBA GMT ratio by MenB strain at Day 31 hSBA geometric mean titers, one booster dose in Primed and first dose in Naïve participants 0 5 10 15 20 25 Group GMT ratio, Primed against Naïve (95% confidence interval) fHbp GMT 24.2 and 6.2 2.78 to 5.46 3.89 NadA GMT 844.9 and 54.3 10.72 to 22.55 15.55 NHBA GMT 14.0 and 10.4 1.004 to 1.82 1.35 PorA GMT 10.0 and 5.7 1.25 to 2.50 1.77 The record sets the superiority criterion as a lower limit of the 2-sided 95% confidence interval of the ratio above 1. The ratios used ANCOVA with baseline, age and country as independent variables. From the trial registry record NCT06995430, results first posted November 6, 2026. The Priority Review.

Why it matters

The record's brief summary says the main purpose was to evaluate the immune response and safety of a booster dose of rMenB+OMV NZ, also known as Bexsero, in adolescents and young adults who were first vaccinated as infants. The primary hypothesis was that a booster dose would elicit a stronger immune response in primed individuals than in participants who never received any group B meningococcal vaccine. The DailyMed label for Bexsero, version published Dec 25, 2025, says it is indicated for active immunization to prevent invasive disease caused by Neisseria meningitidis serogroup B, in individuals aged 10 through 25 years. MedlinePlus says Neisseria meningitidis bacteria cause meningococcal disease and that vaccines can help prevent the disease.

Primary outcome at Day 31

The record gives November 6, 2026 as the date results were first posted. Its primary outcome is hSBA geometric mean titers (GMTs) against each of four MenB indicator strains, with between-group GMT ratios of the Primed group against the Naïve group. The record sets the superiority criterion as a lower limit of the 2-sided 95% confidence interval of the ratio above 1.

  • fHbp: GMT 24.2 (95% CI 20.4 to 28.8) in the Primed group and 6.2 (4.7 to 8.2) in the Naïve group. The ratio was 3.89 (2.78 to 5.46).
  • NadA: GMT 844.9 (704.5 to 1013.3) and 54.3 (40.0 to 73.8). The ratio was 15.55 (10.72 to 22.55).
  • NHBA: GMT 14.0 (12.1 to 16.4) and 10.4 (8.1 to 13.3). The ratio was 1.35 (1.004 to 1.82).
  • PorA: GMT 10.0 (8.4 to 11.9) and 5.7 (4.2 to 7.6). The ratio was 1.77 (1.25 to 2.50).

The analysis included 231 Primed and 77 Naïve participants for fHbp and NadA, 215 and 75 for NHBA, and 231 and 76 for PorA. The ratios used ANCOVA with baseline, age and country as independent variables.

Secondary immune response measures

The record lists the percentage of participants with hSBA titers of 4 or higher at Day 31, Primed group against Naïve group:

  • fHbp: 87.9% (95% CI 83.0 to 91.8) and 64.1% (52.4 to 74.7).
  • NadA: 99.1% (96.9 to 99.9) and 87.2% (77.7 to 93.7).
  • NHBA: 85.7% (80.4 to 89.9) and 56.6% (44.7 to 67.9).
  • PorA: 70.7% (64.4 to 76.5) and 41.6% (30.4 to 53.4).

The percentage of participants with a 4-fold increase in hSBA titers relative to Day 1 was 74.9% against 28.6% for fHbp, 98.3% against 68.8% for NadA, 54.9% against 29.3% for NHBA and 51.5% against 30.3% for PorA. The record defines a 4-fold increase as a post-vaccination hSBA titer of 8 or higher for participants with a pre-vaccination titer lower than 2, or a post-vaccination titer at least 4 times the pre-vaccination titer for participants with a pre-vaccination titer of 2 or higher.

Participants

This was an open-label, randomized, parallel study with masking listed as none. Primed participants received 1 dose of rMenB+OMV NZ vaccine at Day 1, after a 3 (2+1) or 4 (3+1) dose schedule during the first 2 years of life. Naïve participants, who never received any group B meningococcal vaccine, received 2 doses, one at Day 1 and one at Day 31. The start date was 2025-07-07 and the primary completion date was 2025-12-15.

Of 312 participants, 234 were in the Primed group and 78 in the Naïve group, and 311 completed the study. One Primed participant was lost to follow-up. Mean age was 15.3 years (standard deviation 2.2) in the Primed group and 14.8 (2.6) in the Naïve group. The record lists 170 female and 142 male participants, and 307 of 312 were White. Sites in Finland, Italy, Spain and the United Kingdom took part.

Safety measures

The safety analysis covered 234 Primed and 78 Naïve participants. For the first 7 days after the Day 1 vaccination, the record counts participants with each solicited event, Primed group first:

  • Administration site: pain 230 and 77, swelling 44 and 12, induration 44 and 10, erythema (redness) 34 and 9.
  • Systemic: fatigue 180 and 58, myalgia 164 and 56, headache 128 and 39, arthralgia 79 and 30, nausea 49 and 17, fever 6 and 1.

Within 31 days, 49 Primed and 11 Naïve participants reported an unsolicited adverse event. One Primed participant and no Naïve participant reported a serious adverse event. No participant reported arthritis, the adverse event of special interest, or an adverse event leading to withdrawal, and no deaths were reported.

Sources