VBI Shares Plunge On Mixed Late-Stage Hepatitis B Vaccine Trial Results

VBI Vaccines Inc VBIV shares were in penny stock territory Monday following the release of data from a late-stage study of its hepatitis B virus vaccine candidate.

What Happened

The thinly traded micro-cap biotech said the Phase 3 study dubbed PROTECT showed that both the co-primary endpoints were met but not the secondary endpoint.

The trial evaluated the efficacy and safety of a 10-microgram dose of Sci-B-Vac, its trivalent HBV, compared with a 20-microgram dose of comparator vaccine Engerix-B. Engerix B, marketed by GlaxoSmithKline plc GSK, is the current standard of care.

The study evaluated 1,607 patients; about 80% were 45 or older. It met the following co-primary endpoints:

• Non-inferiority of seroprotection rate, or SPR, of Sci-B-Vac versus Engerix-B in all subjects age 18 or older, four weeks after a third vaccination at day 196, and;
• Superiority of SPR Sci-B-Vac versus Engerix-B in subjects age 45 or older, four weeks after a third vaccination at day 196.

SPR is the percentage of patients achieving seroprotection, or anti HBsAg levels greater than or equal to 10 mlU/ml, VBI said.

The study did not meet the secondary endpoint of non-inferiority of two doses of Sci-B-Vac at day 168 compared with three doses of Engerix at day 196 in all subjects age 18 and up, according to the company. 

Why It's Important

HBV is one of the most serious global infectious disease burdens, requiring successful vaccination for controlling the infection.

"These results are truly exciting and demonstrate, in a large multicenter controlled trial, the impressive efficacy of Sci-B-Vac at a dose half that of other hepatitis B vaccines," Timo Vesikari, a principal investigator for the study, said in a statement. 

What's Next

VBI said successful completion of a second pivotal Phase 3 study dubbed CONSTANT is required for a BLA filing to the FDA, MAA filing to the EMA and NDS filing to Health Canada.

The company said it expects to release top-line results form the CONSTANT study around the end of 2019 and, contingent on successful completion of the study,expects to file regulatory applications in the U.S., Europe and Canada in mid-2020. 

VBI shares were down 64.8% at 67 cents at the time of publication Monday. 

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