15 February 2019 - - The first subject has been dosed with ASP3772, US-based Affinivax, Inc.'s novel MAPS vaccine targeting Streptococcus pneumoniae (pneumococcus), the company said.

The clinical study protocol "A Phase 1/2, Randomized, Single Ascending Dose Study in Adults (Stage 1) and Randomized, Single Ascending Dose-Finding Study in Elderly Subjects (Stage 2) with ASP3772, a Pneumococcal Vaccine" was initiated by Affinivax's development partner, Astellas Pharma, Inc. following the successful submission of an Investigational New Drug application to the US Food and Drug Administration in December 2018.

Affinivax and Astellas entered into an exclusive worldwide license agreement in February 2017.

The strategic partnership leverages Affinivax's proprietary MAPS vaccine technology platform utilising Affinivax's process development and analytical expertise to advance a novel pneumococcal MAPS vaccine, with Astellas playing a leadership role in development and commercialisation.

This has resulted in the development of ASP3772, a novel vaccine which offers the potential to provide broader protection against pneumococcal disease.

The initiation of clinical testing for ASP3772 triggered a milestone payment of USD 10m to Affinivax from Astellas.

Streptococcus pneumoniae (pneumococcus) is a bacterium frequently found in the upper respiratory tract of healthy children and adults, and can cause serious infections ranging from pneumonia, meningitis, and sepsis, representing a major global health problem.

The World Health Organization estimates that half a million deaths in children under 5 years old occur each year worldwide due to infection by this bacterium. In the United States, there are over 900,000 cases of pneumococcal pneumonia each year, leading to 400,000 hospitalizations with an associated 5-7% mortality rate in hospitalized patients.

Streptococcus pneumoniae is the leading cause of lower respiratory infection morbidity and mortality globally, contributing to more deaths than all other etiologies combined in 2016.

Prevnar 13 is currently the top selling vaccine worldwide, generating more than USD 5.6bn in sales in 2017.2

The MAPS technology platform uses proprietary chemistry that capitalizes on the highly specific and durable non-covalent, affinity binding between biotin and rhizavidin, a biotin-binding protein.

The highly stable complex created by this affinity binding contributes to a simple, modular, and efficient approach to the development of MAPS vaccines.

In stark contrast to the highly complex chemistry of conventional vaccine conjugation (which is optimized to induce protective antibody responses to only the polysaccharide antigen with the protein antigen serving primarily as a carrier), a MAPS vaccine can present both the polysaccharide antigen and the protein antigen to induce a broad and potent immune response.

Affinivax is advancing a next generation vaccine technology platform to enable the development of vaccines that provide the highest level of protection against challenging infectious diseases.

Backed by an initial investment from the Bill and Melinda Gates Foundation, and working with world experts in vaccine discovery and development, Affinivax is focused on creating a pipeline of vaccines for children and adults in both the developed and developing worlds.

The company's proprietary vaccine platform, called Multiple Antigen Presentation System, enables the high affinity binding of protective polysaccharides and proteins in a single vaccine and uniquely induces a broad and protective immune response.

The MAPS technology provides a highly stable, modular, and efficient approach to develop vaccines against a range of diseases. The company has achieved preliminary preclinical proof-of-concept for several MAPS vaccines and is currently advancing its lead vaccine candidate against Streptococcus pneumoniae in clinical trials.

Affinivax and Astellas entered into an exclusive worldwide license agreement in February 2017 to develop and commercialize a vaccine targeting Streptococcus pneumoniae (pneumococcus).

The partnership will utilise Affinivax's proprietary MAPS vaccine technology platform to advance a novel MAPS vaccine targeted to prevent and reduce the spread of pneumococcal disease.

Astellas will lead and fully fund the development program and obtain worldwide rights to commercialise the MAPS vaccine for pneumococcal disease. Affinivax is eligible to receive a range of development milestones and commercial milestones, as well as tiered royalties on any future product sales.