Periodic Reporting for period 2 - ETVAX (ETVAX – the first oral vaccine for protection against traveller’s diarrhoea caused by ETEC)
Reporting period: 2018-09-01 to 2020-05-31
Scandinavian Biopharma is developing ETVAX – an oral vaccine against traveller’s diarrhoea caused by enterotoxigenic E. coli bacteria (ETEC). ETVAX has a strong potential to be the first vaccine with a full ETEC indication. The development of the vaccine is run in collaboration with the world’s most prominent experts in ETEC vaccine research (e.g. professor Ann-Mari Svennerholm and Professor Jan Holmgren, Göteborg University and Dr August Bourgeois, PATH.
The Phase IIb study at the core of the project will allow Scandinavian Biopharma to progress towards commercialization of ETVAX.
The project has attracted major media attention as well as scientific attention and World Health Organization is following the project closely.
The primary results confirm the excellent safety and overall positive immunogenicity of ETVAX®. While not reaching our protective efficacy goal of 70%, we are pleased to see a significant protective efficacy (PE = 56%) against all severe diarrhea, regardless of pathogen, most likely because ETEC was found in 75% of all severe diarrhea cases.
Despite the higher than expected TD attack rate and severity of ETEC-associated disease, ETVAX® provided significant protection. The PE against moderate-to-severe disease among vaccine responders (≥4-fold seroconversion to LTB) against any ETEC, and allowing for concomitant presence of EAEC, EPEC, EIEC/Shigella, Salmonella sp., Campylobacter sp., and parasites, was 52% (p=0.006; 95% CI=18-72%), representing 25% of all TD. When disregarding vaccine immune response, the protection remained significant (PE=41%, p=0.02; 95% CI=7-63%). Mixed infection with ETEC of another toxin and/or CF phenotype proved surprisingly common (18% of VPO ETEC cases) and decreased the measured protective capacity slightly. Overall, the PE against diarrhea of any cause (including viral pathogens) affecting daily activities increased progressively with increasing severity of disease, so that among vaccine responders with ≥16 loose stools in 24 hours the PE was 56% (p=0.025 CI= 9-83%) and disregarding the vaccine immune response it was 43% (p=0.05). This represents 22% of all TD.