Sci-B-Vac vs. Engerix-B in a Phase 3 Comparison

A commercial-stage biopharmaceutical company announced positive top-line results from the randomized, double-blind, pivotal Phase 3 study designed to evaluate the efficacy and safety of Sci-B-Vac®, a trivalent hepatitis B vaccine. 

Sci-B-Vac is a licensed, third-generation hepatitis B vaccine that has demonstrated safety and efficacy in over 500,000 patients. 

The PROTECT clinical study compared VBI Vaccines Inc.’s Sci-B-Vac with GSK’s Engerix-B®, an FDA approved vaccine indicated for immunization against infection caused by all known subtypes of hepatitis B virus. 

This study, which enrolled a total of 1,607 adults, met both of its co-primary endpoints. This new press release offered this study’s following highlights:

• Both co-primary endpoints were successfully met, including non-inferiority in all adults age ≥18 years, and superiority in adults age ≥ 45 years
• Seroprotection rates 4 weeks post-3rd vaccination of Sci-B-Vac vs. Engerix-B were statistically significantly higher in key subgroup analyses of adults age ≥ 18 years
• The safety and tolerability were consistent with the known profile of the Sci-B-Vac vaccine

Successful completion of the second pivotal Phase 3 study, CONSTANT, is required for the Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA), the Marketing Authorisation Applications (MAAs) to the European Medicines Agency (EMA), and the New Drug Submission (NDS) to Health Canada. 

Sci-B-Vac is currently approved for use in Israel and 10 other countries.

Dr. Timo Vesikari, M.D., Ph.D., Director of Vaccine Research Center at the University of Tampere Medical School in Finland, and a principal investigator of the PROTECT and CONSTANT studies, said in a press release, “If approved, Sci-B-Vac could play an important role in the prevention of hepatitis B, addressing a significant unmet medical need in the adult population.”

The study did not meet the secondary objective of non-inferiority of 2 doses of Sci-B-Vac® (at day 168) compared with 3 doses of Engerix-B® (at day 196) in all subjects age ≥ 18 years.

However, the SPR of Sci-B-Vac compared with Engerix-B was statistically significantly higher at each time point on a per-visit basis.

Hepatitis B is a liver infection caused by the Hepatitis B virus (HBV). For some people, hepatitis B is a short-term illness, but for others, it can become a long-term, chronic infection, says the Centers for Disease Control and Prevention (CDC). 

In 2016, a total of 3,218 cases of acute hepatitis B were reported from 48 states to the CDC.

Recent hepatitis B vaccine news:

• Hepatitis B Vaccine HBAI20 Produced Enhanced Seroprotection For Non-Responders
• A Scientific Strategy To Cure Hepatitis B
• Hepatitis B Vaccine Candidate For Long-Term Immunological Cure Doses 1st Patient 

Jeff Baxter, VBI’s president, and CEO said: “We expect top-line results from our second pivotal Phase 3 study, CONSTANT, around year-end 2019 – all subjects have received the final vaccination and safety follow-up visits are underway.”   

“Pending successful completion of CONSTANT, we remain on track to submit applications for regulatory approvals in the U.S., Europe, and Canada beginning mid-year 2020.”

Top-line data from the CONSTANT study is expected around year-end 2019.

Vaccines, like any medicine, can cause side effects. You are encouraged to report negative side effects of vaccines to the CDC.