Pfizer Inc., one of the world's premier innovative biopharmaceutical companies, announced positive topline results of two phase 3 studies of Trumenba (meningococcal group B vaccine).

One study included approximately 3,600 healthy individuals 10 through 18 years of age, and the other study included approximately 3,300 healthy individuals 18 through 25 years of age. Both studies met all primary immunogenicity endpoints, demonstrating robust immune responses against certain invasive meningococcal B strains after the vaccine dose series. Safety and tolerability data from both studies were also consistent with data from previous studies.

“We are very pleased with these phase 3 data that show immunogenicity and safety data consistent with findings that formed the basis for the accelerated FDA approval of Trumenba,” said Kathrin Jansen, Ph.D., senior vice president of vaccine research and development, Pfizer Inc.

“The phase 3 data extend the body of evidence that supports vaccination of adolescents and young adults with Trumenba to help prevent serogroup B meningococcal disease.”

In October 2014, Pfizer’s Trumenba was granted accelerated approval by the US Food and Drug Administration (FDA) for active immunisation to prevent invasive disease caused by Neisseria meningitidis serogroup B in individuals 10 through 25 years of age.

Pfizer plans to present the full results of both studies at an upcoming scientific congress.

Vaccine safety and immunogenicity were evaluated in these two phase 3 studies. One phase 3 study was a randomized, active-controlled, observer-blinded study that included approximately 3,600 healthy individuals 10 through 18 years of age in the United States and Europe. Individuals were randomized to receive one of three different lots of Trumenba in a 0, 2, 6 month schedule or a control. The control group received a licensed hepatitis A (HAV) vaccine at 0 and 6 months and saline at 2 months. The primary endpoints assessed immunogenicity, lot consistency and safety.

Immunogenicity: Demonstration of an immune response measured by serum bactericidal assays with human complement (hSBA) for 4 primary test strains 1 month after the third vaccination with Trumenba.

Lot consistency: hSBA geometric mean titers (GMTs) for 2 primary test strains (A22 and B24) measured 1 month after the third vaccination for individuals receiving one of three different lots of Trumenba.

Safety: Proportion of subjects who reported local and systemic reactions, adverse events (AE), serious adverse events (SAE), newly diagnosed chronic medical conditions (NDCMC), medically-attended adverse events (MAE), autoimmune diseases and neuroinflammatory conditions following vaccination with  Trumenba or a control.

A second phase 3 study was a randomized, placebo-controlled, observer-blinded study that included approximately 3,300 healthy individuals 18 through 25 years of age in the United States and Europe. Individuals were randomized to receive Trumenba or a saline control in a 0, 2, 6 month schedule. The primary endpoints assessed immunogenicity and safety.

Immunogenicity: Demonstration of an immune response measured by hSBA for 4 primary test strains 1 month after the third vaccination with Trumenba

Safety: Proportion of subjects who reported local and systemic reactions, AEs, SAEs, NDCMCs, MAEs, autoimmune diseases and neuroinflammatory conditions following vaccination with  Trumenba or placebo

Trumenba is indicated for active immunisation to prevent invasive disease caused by Neisseria meningitidis serogroup B in individuals 10 through 25 years of age.

Approval of Trumenba is based on the demonstration of immune response, as measured by serum bactericidal activity against four serogroup B strains representative of prevalent strains in the United States. The effectiveness of Trumenba against diverse serogroup B strains has not been confirmed.

The most common adverse reactions with Trumenba were pain at the injection site, fatigue, headache, muscle pain, and chills.

Data are not available on the safety and effectiveness of using Trumenba and other meningococcal group B vaccines interchangeably to complete the vaccination series.

Trumenba is a sterile suspension composed of two recombinant lipidated factor H binding protein (fHBP) variants from N. meningitidis serogroup B, one from fHBP subfamily A and one from subfamily B (A05 and B01, respectively). fHBP is one of many proteins found on the surface of meningococci and contributes to the ability of the bacterium to avoid host defenses. fHBPs can be categorized into two immunologically distinct subfamilies, A and B. The susceptibility of serogroup B meningococci to complement-mediated, antibody-dependent killing following vaccination with Trumenba is dependent on both the antigenic similarity of the bacterial and vaccine fHBPs, as well as the amount of fHBP expressed on the surface of the invading meningococci.

As with any vaccine, Trumenba may not prevent disease in all vaccinated individuals. The frequency of meningococcal disease caused by serogroup B varies geographically, and could influence the ability to evaluate effectiveness of the vaccine in any given country. Based on the low incidence of meningococcal disease, placebo-controlled clinical trials for Trumenba were considered unfeasible due to the size of the study that would be required and were not performed. Licensure of Trumenba was based on demonstration of immune responses measured using a serum bactericidal assay with human complement (hSBA).

In 2014, Trumenba was reviewed and received accelerated approval under the FDA's Breakthrough Therapy designation and Priority Review programmes.

The majority of invasive meningococcal disease cases worldwide can be attributed to five Neisseria meningitidisserogroups (A, B, C, W and Y). Meningococcal serogroup B disease affects all age groups in the US, but incidence is highest among infants younger than one year, adolescents and young adults. In 2013, approximately 500 cases of meningococcal disease occurred in the United States, more than 30 per cent of which were caused by serogroup B.

Serogroup B meningococcal disease may result in life-altering, significant long-term and permanent medical disabilities. Despite the availability of antibiotic treatment, 12.5 per cent of patients with meningococcal serogroup B disease die and many of those who survive are afflicted with long-term disabilities, such as brain damage, hearing loss, learning disabilities or limb amputations.