Clinical Trial Info

A Study to Qualify an In-house Reference Standard Batch of Sci-B-Vac™

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This Phase 4 study was a post-marketing, open-label, single-arm study in healthy volunteers who had never been vaccinated with any hepatitis B vaccine and who were seronegative to HBsAg, Hepatitis B core (HBc), and HBs antibodies.

This study consisted of three periods: screening period (up to 1 month prior to first vaccination), treatment (Day 1 to month 6), and post-vaccination follow-up period (months 6 -12). Immunogenicity endpoints were examined one month after the first injection and at every month until month 6, then at months 7, 9, and 12.

The primary safety endpoint was the frequency, severity, and duration of adverse events, including clinically significant laboratory abnormalities after administration of Sci-B-Vac™.


In this open-label, single-arm Phase 4 study in 91 healthy adults age 20-40 years, this objective was achieved two months after the second dose – the SPR at month 3 was 98.8%. SPR is defined as the percent of participants who achieve antibody titers (anti-HBs titers) above the protective threshold of 10 mIU/mL.

Additional results from this Phase 4 study include:

By month 7, after receiving three doses, all enrolled participants (100%) were seroprotected

The majority of participants were high responders, defined as achievement of anti-HBs titers ≥ 100 mIU/mL – high-responder SPR was 81.4% and 97.6% at month 3 (after 2 doses) and month 7 (after 3 doses), respectively

The geometric mean concentration (GMC) of anti-HBs titers were also substantially above the protective threshold at 413.6 mIU/mL and 6799.9 mIU/mL at month 3 and month 7, respectively

Anti-HBs titers were maintained above 2000 mIU/mL at month 12, suggesting a potent and sustained response

Consistent with other clinical data, VBI’s 3-antigen HBV vaccine was well-tolerated with no safety signals observed.