Data presented as invited oral presentation at 10th International Symposium on Pneumococci & Pneumococcal Diseases
- Antibody responses to ubiquitous antigens across strains shown, indicative of broad protection
- Statistically significant increases in antibody response were achieved in the 200 (mid) and 500 µg (high) dose groups, in comparison to the placebo group
- 100% of subjects in the high dose group achieved a significant immune response
- Study demonstrated a dose response relationship
- Proven safety will allow further development of the vaccine, specific to at-risk groups for pneumococcal disease
PnuBioVax was found to be safe and well tolerated, and capable of producing antibody responses against key S. pneumoniae antigens broadly conserved across strains. The data was presented today (Thursday) at the International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD), Glasgow, UK.
“The results of this study have demonstrated the safety of PnuBioVax in adults, and we are now looking at developing the vaccine further, focusing on the at-risk populations for pneumococcal disease of the young and the elderly” said Dr Chris Bailey, Development Director at ImmBio.
Graham Clarke, CEO of ImmBio, commented: “Demonstrating that PnuBioVax is safe and immunogenic through this phase I clinical study is a fundamental step in our mission to create a universal vaccine against pneumococcal disease. This provides the real prospect of a strain-independent pneumococcal disease prophylactic vaccine. We are now looking for partners to progress PnuBioVax through late stage clinical development, manufacturing and marketing”.
Study Design
The randomised, double blind study assessed the safety and immunogenicity of PnuBioVax for three different dosages (50 μg, 200 μg, and 500 μg) compared to placebo. Doses of PnuBioVax were administered intramuscularly on three occasions, 28 days apart. A total of 36 healthy males and females, aged 18 to 40 years, were recruited for the study.
In addition to monitoring volunteers for adverse events, antibody responses to PnuBioVax were measured by ELISA, using blood samples taken from the volunteers at four separate occasions throughout the study. The presence of specific antibodies, against antigens selected for their ubiquity across strains and role in causing disease, was also measured. The functional capacity of these antibodies was assessed using an opsonophagocytic assay, commonly used as an indicator of an antibodies’ ability to kill the pathogen and therefore protect against disease. The ability of antibodies raised against PnuBioVax to neutralise the toxic component of S.pneumoniae, Pneumolysin (Ply), was also assessed.
Safety data
Assessment of safety data concluded that no clinically-significant changes of vital signs, ECG and blood chemistries were observed as a result of treatment with PnuBioVax, and, importantly, no serious adverse events were seen. Overall, PnuBioVax was concluded to be safe and well tolerated. This is in accordance with expectations of PnuBioVax’s safety profile as a self adjuvanting vaccine.
Immunogenicity data
A statistically significant increase in total antibody response was seen in the 200 and 500 µg dose groups compared to placebo, showing PnuBioVax to be immunogenic. In addition, 100% of subjects in the high dose group achieved a significant immune response. Response to specific disease relevant antigens, such as Ply and Pneumococcal surface protein A (PspA) were also observed, indicating PnuBioVax’s capability of broad protection across strains. The range of doses used was able to demonstrate a relationship between dose and antibody response. The study showed no clear advantage of a 500 µg dose over 200 µg dose of PnuBioVax.
A correlation was seen between antibodies generated against Ply and inhibition of the haemolytic effects of the pathogen on red blood cells. This is indicative of PnuBioVax’s ability to neutralise the Ply toxin, a factor implicated in the virulence of S. pneumoniae.
Dr Chris Bailey presented the phase I data today during the session ‘Invited Oral Poster Presentations 07: New Pneumococcal Vaccines’ at ISPPD. The abstract can be found online, here: http://www.isppd2016.kenes.com/scientific-program-%282%29/scientific-program-2#.V2v77FUrLGg
ImmBio is also presenting three posters focused on PnuBioVax at ISPPD.
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