The only commercially-available 3-antigen vaccine containing pre-S1, pre-S2, and S antigens of Hepatitis B
Sci-B-Vac® is a licensed, third-generation hepatitis B vaccine that has demonstrated safety and efficacy in over 500,000 patients. Sci-B-Vac® is approved for use and commercially-available in Israeli. In December 2017, VBI initiated patient dosing in a global Phase 3 clinical program that consisted of two concurrent pivotal studies: PROTECT, a safety and immunogenicity study, and CONSTANT, a lot-to-lot consistency study. Data from both the PROTECT study and the CONSTANT study, which were announced in June 2019 and January 2020, respectively, will comprise the basis for the regulatory submissions in the U.S., Europe, and Canada, expected to begin in the second half of 2020.
- Mimics all three surface antigens of the hepatitis B virus (“HBV”)
- Offers high levels of anti-HBV antibodies
- Offers rapid onset of protection
- Can be administered at lower doses than competing hepatitis B vaccines
- Free of next-generation adjuvants
Second-Generation Hepatitis B Vaccine
About Hepatitis B
Hepatitis B Unmet Need: Low Vaccination Rates
Hepatitis B is a disease of the liver caused by the hepatitis B virus (“HBV”), characterized by liver inflammation, injury, and even cell death. The disease can present acutely, and resolve on its own, or it can progress to a chronic state. Despite advances in currently available antiviral therapies, only a minority of patients with chronic hepatitis B will have a sustained immune response to treatment. Therefore, primary prevention by vaccination is considered the ideal way to control hepatitis B infection.
Hepatitis B vaccines have been available for more than two decades, but infection with HBV remains a worldwide health problem, largely due to low vaccination rates. In a 2015 surveillance study, the U.S. Centers for Disease Control and Prevention (“CDC”) found that hepatitis B vaccination coverage (defined as having received three or more doses of a hepatitis B vaccine) was only 25% among adults aged 19 and older, 32% among adults aged 19 to 49, and 17% among adults aged 50 and up.
In addition, while second-generation HBV vaccines are highly protective against hepatitis B in young individuals, as individuals age, the immune system’s capacity to elicit a protective response decreases. The likelihood of success decreases further if you consider other comorbidities such as diabetes and end-stage renal disease (“ESRD”). Given the aging U.S. population and the low rate of adult hepatitis B vaccination in the U.S., it is becoming increasingly important to develop a hepatitis B vaccine that can induce a more immunogenic response.
U.S. Hepatitis B Vaccination Coverage (≥ 3 doses)
|Adults Aged ≥ 19 years||24.6%|
|Adults Aged 19-49 years||32.0%|
|Adults Aged ≥ 50 years||16.5%|
|Chronic Liver Conditions||27.4%|
|Diabetics – Aged 19-59 years||24.4%|
|Diabetics – Aged ≥ 60 years||12.6%|
|Healthcare Providers ≥ 19 years||64.7%|
2015 CDC Surveillance of Vaccination Coverage Among Adult Populations
Phase III Clinical Program
PROTECT – Safety and Immunogenicity Study
PROTECT is a double-blind, two-arm, randomized, controlled study, that enrolled subjects 18 years of age and older. Subjects were randomized in a 1:1 ratio to receive either a three-dose course of Sci-B-Vac® 10 μg or a three-dose course of the control vaccine, Engerix-B® 20 μg. Under the planned dosing schedule, subjects were vaccinated at months zero, one, and six. Enrollment was stratified by age group.
The co-primary objectives of the PROTECT study are:
- To demonstrate non-inferiority of the seroprotection rate induced by Sci-B-Vac® vs. Engerix-B® four weeks after the third vaccination in adults age 18 and older.
- To demonstrate superiority of the seroprotection rate induced by Sci-B-Vac® vs. Engerix-B® four weeks after the third vaccination in adults older than 45 years of age.
The study also includes multiple secondary objectives to evaluate the speed to seroprotection, including assessment after two doses of Sci-B-Vac® vs. three doses of Engerix-B®, and the overall safety and tolerability of Sci-B-Vac® vs. Engerix-B®.
CONSTANT – Lot-to-Lot Consistency Study
CONSTANT is a double-blind, four-arm, randomized, controlled study. 2,838 subjects, age 18-45 years, were randomized in a 1:1:1:1 ratio to receive one of four three-dose courses: Lot A of Sci-B-Vac® 10μg, Lot B of Sci-B-Vac 10μg, Lot C of Sci-B-Vac® 10μg, or the control vaccine Engerix-B® 20μg.
The primary objective of this study is:
- To demonstrate lot-to-lot consistency for immune response as measured by geometric mean concentration (GMC) of antibodies across three independent, consecutive lots of Sci-B-Vac four weeks after the third vaccination.
The secondary objective will be to evaluate safety and efficacy of Sci-B-Vac vs. Engerix-B®.