US-based VBI Vaccines is set to evaluate its third-generation hepatitis B vaccine Sci-B-Vac in a global Phase III clinical programme after positive discussions with the US Food and Drug Administration (FDA), Health Canada and the European Medicines Agency (EMA).
Sci-B-Vac is currently approved in 15 countries and comprises S antigen, pre-S1 and pre-S2 surface antigens, which are expected to be immunogenic for patients who are not responding to existing second-generation vaccines.
Planned to be conducted at up to 40 centres across the US, Europe and Canada, the Phase III programme will include two concurrent trials, PROTECT and CONSTANT, in around 4,800 patients.
VBI Vaccines president and CEO Jeff Baxter said: “Sci-B-Vac’s extensive safety and efficacy data package demonstrates safe and effective vaccination of approximately 2,000 subjects in past clinical trials.
“Because of this track record, we are able to plan a Phase III programme that will enrol only 4,800 subjects in total and will be only 15 months in duration.”
PROTECT is a double-blind, two-arm, randomised, controlled safety and immunogenicity trial to be conducted in 1,600 patients aged 18 and above with a three-dose course of 10μg Sci-B-Vac.
The trial’s co-primary objectives are non-inferiority of the seroprotection rate in subjects 18 and above and superiority of the seroprotection rate in adults above 45 at four weeks following the third vaccination.
The secondary objectives include speed to seroprotection, and overall safety and tolerability of Sci-B-Vac.
The double-blind, four-arm, randomised, controlled CONSTANT trial is to be performed in 3,200 subjects aged between 18 and 45 and will adopt a lot-to-lot consistency design with four three-dose courses of 10μg Sci-B-Vac.
The primary objective of this trial is lot-to-lot consistency at four weeks following the third vaccination, while the secondary objective is Sci-B-Vac’s safety and efficacy.
Both trials will compare Sci-B-Vac with 20μg Engerix-B and plan to commence patient recruitment in the second half of this year.