Affinivax is applying its proprietary MAPS platform to develop a pipeline of vaccines that confer broader disease protection than existing vaccines, as well as vaccines against infectious diseases for which there are no effective immunization strategies today. The MAPS technology platform is uniquely suited to target complex mucosal pathogens involved in infectious diseases for which antibodies alone, or antibodies in combination with T cells, play important roles in protection. Affinivax has achieved preliminary preclinical proof-of-concept for MAPS vaccines against several bacterial pathogens and is currently advancing two MAPS vaccine programs to the clinic.
Lead Vaccine Program for Streptococcus Pneumoniae
Streptococcus pneumoniae 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 more than 1.6 million people, including more than 800,000 children under 5 years old, die every year from pneumococcal infections, with most of these deaths occurring in low-resource countries. The U.S. Center for Disease Control estimates that about 900,000 cases occur in the U.S. alone, resulting in up to 400,000 hospitalizations and 50,000 deaths annually. By overcoming the technical challenges of conventional conjugate vaccine approaches and inducing a broader protective immune response, a more affordable MAPS vaccine against Streptococcus pneumoniae offers the potential to make a significant global impact on this pneumococcal disease.
Affinivax is advancing a lead program in Streptococcus pneumoniae (pneumococcus), a pathogen that is responsible for considerable morbidity and mortality worldwide. In Affinivax’s MAPS vaccine against pneumococcus, proprietary pneumococcal protein antigens enable the potential for an additional antibody response to protect against disease due to a broader range of ‘non-vaccine’ pneumococcal serotypes, beyond what is covered by today’s vaccines. The MAPS complex also enables these protein antigens to elicit a T cell response to reduce nasopharyngeal colonization (nasal carriage of pneumococcal bacteria), the first and essential step in pneumococcal infection. Preclinical in vivo data with Affinivax’s prototype MAPS vaccine against Streptococcus pneumoniae demonstrated that the MAPS platform enables the creation of a defined-structure and highly reproducible macromolecular complex with the desired ratio of antigen components – pneumococcal polysaccharides and pneumococcal proteins. The pneumococcal MAPS vaccine induces a robust, multipronged immune response, including antibody responses comparable to current standard of care vaccines, as well as additional protective antibody and Th1 and Th17 responses.
Bacterial Nosocomial Infections
Bacterial nosocomial infections, also referred to as health-care associated infections (HAIs), are a significant global health concern, with the Centers for Disease Control and Prevention estimating that 4% of patients in the U.S. will contract an HAI each year in medical facilities, including ambulatory surgical centers, hospice centers, nursing homes and rehabilitation centers. JAMA Internal Medicine has reported that HAIs cost $9.8 billion annually in the U.S. alone. Bacterial nosocomial infections represent one of the most common HAIs, caused by bacteria that are highly resistant to available antibiotic therapies. In addition to the limitations of current treatments against nosocomial infections, there are no vaccines available today for prevention.
In collaboration with its partner, ClearPath Development Company (with support from Astellas Pharma Inc.), Affinivas is advancing its second program using MAPS to develop vaccines to prevent bacterial nosocomial infections.
Additional Disease Applications
In addition to the company’s ongoing vaccine programs, applicability of the MAPS technology has been demonstrated via vaccine construction and robust immune responses to other pathogens, including Salmonella typhi and Staphylococcus aureus. Based on the modular nature of the MAPS technology, much of the development work required for one vaccine program will facilitate and contribute to accelerating the development of other candidate programs. Future MAPS vaccine programs will be focused on improving the protection offered by existing vaccines as well as targeting pathogens for which there are no effective vaccines available today.