The purpose of the Phase 1/2 study is to evaluate the safety, tolerability, and immunogenicity of 3 different dose levels of ASP3772 in comparison to the active comparator Prevnar 13® (PCV13) in adults 18 to 64 years of age in Stage 1.

Stage 2 will evaluate the safety, tolerability, and immunogenicity of 3 different dose levels of ASP3772 in comparison to the active comparator PCV13 in elderly 65 to 85 years of age. In addition, Stage 2 will evaluate the immunogenicity of 3 different dose levels of ASP3772 relative to the response seen following administration of Pneumovax® 23 (PPSV23) for the serotypes not included in PCV13.

Results

Results of this trial were delivered in an oral presentation at the 31st European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), taking place online from 9-12 July 2021.

The Phase 2 clinical trial1 of ASP3772 was conducted in 503 adults 65 to 85 years of age, and 293 adults received ASP3772, 97 adults received Prevnar13® and 113 adults (who were previously vaccinated with Prevnar13®) received Pneumovax®23. The primary objective was to evaluate safety/tolerability and reactogenicity of ASP3772 compared to Prevnar13®. The secondary objective was to evaluate the immunogenicity of ASP3772, versus Prevnar13 or Pneumovax®23.

The results from the Phase 2 clinical trial demonstrated that ASP3772 was well tolerated. ASP3772 also exhibited an antibody response to each of the 24 polysaccharides, as well as an additional antibody response to the conserved pneumococcal proteins.